Home

Care and Service of Passenger and Light Truck

1. STEP 2a STEP STEP 20 Calculated Scale Weight Ibs E 227 Calculate Other bs Side Weg Tro Lond be eer ination do psi G Travel Trailer To Obtain Individual Axle and Gross Vehicle Weights STEP 1d STEP 10 STEP at Scale Weight bs ls oara Ma A From Owners be e bs Manu un Gun E Obtain Individual Wheel Position Weights STEPad STER STEP at H One Site Js is de be Scale Weight a Calculate Other tbs tos m Sido Weight Germ Ut et rrr mre oum Dm Tire Load Ibs Ibs Ibs Ibs CTT Inflation Seer Nl 2 1 vehicle los dui ead dul apc om te an ay G to cll dual ad capat Chapter 4 Page 57 Sudden Ride iturbance ration If the vehicle experiences a sudden vibration or ride disturbance and or there is a possibility the tires and or vehicle have been damaged gradually reduce speed Do not abruptly brake or turn Drive with caution until you can safely pull off the road Stop and inspect the tire If the tire is under inflated or damaged deflate and replace it with the spare tire Ifa cause cannot be detected the vehicle should be towed to the nearest vehicle or tire dealer for an inspection Tire Rotation Rotating tires will help even out the a
2. tzebkPa 2a0 Pa CsoiPa KEJ 1589 F vas uses 9nmU su e vms 397 Chapter 1 Page 10 Uniform Tire Quality Grading Standards for Passenger Car Tires The National Highway Traffic Safety Administration NHTSA established the Uniform Tire Quality Grading Standards UTQG as a way to assist the consumer to compare various tres UTQG applies to the vast majority of passenger car ties excluding tires such as winter type snow tires NHTSA sets the standards that rate the relative performance of tires based on three criteria eadwear traction and temperature The grades are molded on the tire sidewall Replacement tires have label affixed to the tread that lists and explains these grades A vehicle s engine type transmission type gear ratios driving styles road surface inflation pressure etc can affect actual performance of the tire from one vehicle to another The UTQG tire characteristics are as follows readwear The treadwear grade is a comparative based on the wear rate of the tire when tested under controlled conditions on specified government test course In the example shown the treadwear grade is 600 which means
3. which provides abrasion scuff and weathering resistance Tread The tread rubber compound and tread pattem provide grip and abrasion resistance Contributing to traction and treadwear Chapter 1 page 2 Cross Section of Tire and Rim Section Height The height of a new tire from the nominal rim diameter to the top of the tread Section Width The width of a new tire including normal sidewalls but not including protective side ribs bars or other decorations Overall Diameter Twice the section height unloaded plus the nominal rim diameter Rim Width The measurement on the inside of the rim between the two flanges Rim Diameter Code The nominal rim diameter in inches 4 3 Size designation systems presently in use P Metric European Metric Metric LT High Flotation LT Numeric European Commercial Metric C Type Special Trailer Temporary Spare Size designations usually include letters as well as numbers which have the following meanings 2323232333 P P Metric Passenger Light Truck C European Commercial Light Duty ST Special Taller Temporary Spare R Radial Construction F Self Supporting Runflat D Diagonal Bias Construction Belted Bias Construction 33233233233 Other letters denoting speed symbols such as ST U IW Av n elc may appear in the tire size designation
4. Vehicle Certification Label Vehicle Tire Placard This chapter contains additional guidelines to help Motor Home Occupant and Cargo Carrying obtain the best performance from tires used on RVs Capacity Label Use this chapter in conjunction with the other FV Trailer Cargo Carrying Capacity Label chapters in this manual Unless otherwise specified Motor Home Supplemental Label 1 the term RV applies to motor homes travel RV Trailer Supplemental Label trailers sth wheel travel trailers and sldein Load Carrying Capacity Modification Label for pickup trucks and 2 the term RV tires fenes tics Used om RV vehicles More These placards labels may be found in diferent information about the specific vehicle and its tires is locations depending upon the vehicle including the contained in the owner s manual supplied by the following vehicle manufacturer Additional information concerning RV tires is available from the tire Left Side Driver s door edge hinge pillar or door latch Ri Forward mast exterior passenger door The Recreational Vehicle Safety Education hinge pillar or door latch post Foundation RVSE has weighed over25 000 motor Vehicle Interior Posted on a surface near the driver homes and travel trailers in conjunction with RV storage area events Of the RVs checked by RVSEF more than s7 Vehicle Exterior Posted on surface near the trailer percent had loads
5. Figure 4 Tread wear Indicators Wear Bar Based on the read Hears on the left side of the above the worn out Consumers should check their tire tread and sidewall areas during monthly inflation pressure checks looking for uneven or irregular tread wear cuts cracks scrapes snags bulges foreign objects other damage Driving on damaged tires is dangerous A damaged tire can suddenly fall leading to Situations that may result in serious personal injury or death Tires should be regularly inspected by a qualified tire service professional Pal pons 9 CFR STU and 6 CR TR A manual published by the Tire Industry Association entitled Passenger and Light Truck Tire Conditions Manual may be used by service garages tire dealers state motor vehicle inspection stations elc as a reference for inspection of tires rims and wheels Reasons for Tire Rim Wheel or Valve Removal If any of the conditions below are found when Inspecting a tire rim wheel or valve the item should be removed from service Note this list is not all inclusive Tread Conditions Wom to 2 32 1 6 mm or less anywhere on the face of the tread and or tread wear indicators showing Localized spot wear due to separation Cuts cracks bulges or snags in the tread or groove exposing cord or fabric material excludes repairable conditions Unrepairable punctures sidewall Conditions I
6. Chapter 4 page 48 Chapter 4 page 48 Chapter 4 page 49 Chapter 4 page 50 Chapter 4 page 52 Chapter 4 page 53 Chapter 4 page 54 Chapter 4 page 54 Chapter 4 page 58 Chapter 4 page 58 Chapter 4 page 58 Chapter 4 page 59 Chapter 4 page 60 Chapter 4 page 61 Chapter 4 page 61 Purpose The purpose of this manual is to provide both the service professional and end user consumen with an understanding of the many factors that are essential to the proper care and service of Passenger and light truck tires also known as vehicle tres This manual is not all inclusive RMA does not intend for it to eliminate the need for in depth hands on training especially in such areas as tire mounting and demounting and wheel balancing retreading re pressure monitoring systems TPMS and repairing Personnel that service tires must receive professional raining Tire manufacturers and Industry organizations such as the Industry Association provide comprehensive hands on training programs for service professionals The WARNINGS and CAUTIONS contained in RMA publications are important and must be followed Questions pertaining to specific products or pieces of service equipment should be addressed directly to the manufacturer of that product RMA does not endorse certify approve consent or confirm in any way products brands creationszinventions eic of any company corp
7. Remove any stones glass foreign objects etc embedded in the tread to prevent damage Even minor damage can lead to further injury and eventual tire failure Also it is a good practice to check between dual tire wheel assemblies for foreign objects like large rocks that may have become lodged between the tires especially after off road service Tires with excessive cracking on the tread or sidewalls should be removed from service This is typically caused by under inflation over loading improper storage and or improper long term parking RV tires should be checked for this condition and any other damage before every trip For more information regarding tire inspection guidelines and tire damage see Chapter 2 Tire Care and Service Driving on damaged tires is dangerous A damaged tire can suddenly fail leading to situations that may result in serious personal injury or death Tires should be regularly inspected by a qualified tire service professional Replace tires when worn to 2 32 1 6 mm depth remaining anywhere on the tread face For vehicles with a GVWR in excess of 10 000 pounds 4 536 kg federal regulations state that tires on the front axle should be removed when worn to 4 32 3 2 mm tread depth at Severe Service Operation RV tires will wear out faster when subjected to high speeds and high loads as well as hard comering rapid starts sudden stops and driving off road or on surfaces tha
8. change is affected by many elements such as temperature storage conditions and conditions of use eg load speed inflation pressure impacts Chapter 4 Page and road hazard injury to which a tire is subjected throughout its life Since service and storage conditions vary widely accurately predicting the service life of any specific tire based on calendar age is not possible RMA is not aware of scientific or technical data that establishes or identifies a specific minimum or maximum service life for passenger and light truck tires However in some cases a tire or vehicle manufacturer may make a specific tire Teplacement recommendation regarding its products If so the consumer should consult the manufacturer with any questions with regard to following the recommendation Further any such recommendation should not be considered a minimum service life for the tire Proper Tire Repair Tires driven even a short distance while under inflated may be damaged beyond repair Running tire under inflated is like running the vehicle s engine without enough oil or coolant It may seem to work fine for a time but serious permanent damage has occurred Adding oll or coolant won t repair engine damage and adding inflation pressure won t fix tire damage The tre will remain seriously damaged and can still fail even after inflation pressure is corrected 1 a tire is losing inflation pressure a tire service professional shoul
9. hub centric or lug centric wheels With larger passenger and light truck tires ange plate adaptors may be required to obtain accurate tire wheel balance Tire Wheel Installation Consult the vehicle owner s manual for recommendations on tire wheel assembly installation Identify lug torque specifications for proper installation It is recommended that lug nuts and bolts be tightened to exact torque specifications with a torque wrench Improper torque either too loose or too tight may cause loss of lug nuts breaking of the studis damage to the tire wheel assembly or detachment of the re wheel assembly from the axle Never use air tools to install custom wheels Always use a torque wrench for final tightening and follow accepted tightening torquing procedures TIRE SEALANTS AND BALANCING SUBSTANCES Solvent based liquids must not be used due to the possibility of creating explosive mixtures of vapors in the tire which may result in serious injury or death Chapter 2 Page 32 Ride Comfort Optimization Procedures and Diagnostics Manufacturer Match Mount Markings New tires are often marked by the manufacturer to indicate the location known as the high point that should be matched to a particular location on a wheel The marking is generally a colored spot on the sidewall It should be matched to a location on he wheel known as the low point often at or near the va
10. the vehicle should be rocked gently altemately using forward and reverse gears with the least amount of wheel spinning Repeatedly shift the gear lever from drive to reverse on automatic transmissions reverse to second on manual transmissions while applying gentle pressure to the accelerator Vehicles with ABS or traction control systems need to follow the instructions in their owners manual Never exceed 35 mph 66 km h indicated speed the speedometer Never allow anyone to stand near a spinning tire Excessive speed in a free spinning tire can cause the tire to explode from extreme centrifugal force The energy released by such an explosion is sufficient to cause serious physical injury or death Never spin tire above a speedometer reading of 35 mph 56 km h Never stand near a spinning Mounting and Demounting Procedures For detailed instructions on mounting passenger ind light truck tres refer to the RMA wall chart Demounting and Mounting Procedures for Passenger and Light Truck LT Tires Read and understand the procedures and safety warnings before proceeding For additional information on mounting low aspect ratio high performance passenger and light truck tires refer to RMA Tite information Service Bulletin Vol 46 Proper Tire Mounting of Low Aspect Ratio High Performance Passenger and Light Truck Tires Tire Bead Lubricants Used to Mount Tires Use c
11. Any tire that continually requires re inflation is a serious safety risk The cause may be the result of a puncture road hazard damage leaking valve tire mounting damage or other irregular condition Continuous use of a tire in an under inflated condition will result in heat build up and internal tire damage This may result in a tire failure including tread beit separation Tires that continuously require re Inflation should be inspected thoroughly by a tire service professional and be properly serviced or replaced immediately Inflating an unsecured is dangerous If i bursts it could be hurled into the air with explosive force resulting in serious personal injury or death Never inflate a tire unless it is secured to vehicle ire mounting machine or other restraining device Dual Tire Assemblies For vehicles equipped with dual tire assemblies duals if one of the dual tires becomes significantly underinflated or flat the other tire will the load for both tires resulting in an overloaded condition Both tires should be inspected by a tire service professional for damage Tire Pressure Systems TPMS I is still important to check inflation pressure at least once month even on vehicles that are equipped with a TPMS TPMS are designed to be beneficial and accurate However they should not be solely relied on for inflation pressure maintenance since some systems may have limitations
12. and follow the RMA wall chart Puncture Repair Procedures for Passenger and Light Truck Tires which covers the proper repair procedures for passenger and light truck tres through Load Range E Never repair a tire with an injury that is greater than Y inch 6mm in diameter Do not repair an injury outside the puncture repair area as shown in Figure 6 The basic principles for proper puncture repair Remove the tre from the wheel for inspection and repair Prepare the injured area lll the injury with a suitable vulcanizing material or rubber stem that must fll the injury and keep moisture out Seal the innerliner with a patch to prevent loss of inflation and keep moisture out and Re inspect the finished repair Refer to the RMA wall chart for complete step by step procedures Improperly repaired tires can fail while in service such as by tead belt separation which can lead to an accident and serious personal injury or death Tires must always be properly repaired as described in the RMA wall chart Puncture Repair Procedures for Passenger and Light Truck Tires Not all tires can be repaired In addition to the RMA puncture repair procedures there may be additional limitations based on individual manufacturer repair polices These may include the type of service such as speed rating load index run flat technology and commercial application When repairing a puncture Nev
13. any abnormal wear pattems that were starting to develop may be corrected see Tire Rotation on page 20 Tire and Wheel Assembly Out of Balance and wheel assembly that is out of balance can cause abnormal tread wear due to vibration and irregular road contact which may be worse at specific speeds see page 32 for information on tire Wheel balance Damaged Wheels Damaged wheels can cause a tire to contact the Toad unevenly and cause abnormal tread wear Wheel damage may not be visually obvious and should be checked by a tire service professional using proper measuring equipment Brakes in Disrepair If not in proper working order brakes can grab unevenly and cause abnormal tread wear Worn Struts Shock Absorbers A worn strut or shock absorber will not properly dampen vehicle motion and cause abnormal tread Worn or Loose Suspension and Steering Systems and Worn Ball Joints Excessive wear and looseness anywhere in the suspension and steering systems such tie rod ends and ball joints can cause tire and wheel assemblies to move in ways in which they were not designed This will cause rapid and or abnormal tread wear Examples of Abnormal Tread Wear Diagonal Wear Both Shoulder Wear Center Wear Toe Wear Cupping Wear chapter 2 page 23 Proper Tire Repair ires driven even a short distance while under inflated may be damaged beyond repair Running a tire under inflated
14. causing sparks a well ventilated area and with the tire secured to a vehicle tire mounting machine ther restraining device remove the valve core and completely deflate the tire Reinfale and deflate the tire a few times to further dissipate and expel potentially flammable vapor Never under any circumstance introduce a flammable substance into a tire Igniting this substance in an effort to facilitate seating the beads is extremely unsafe This may result in an explosion of the tire with force sufficient to cause serious personal injury or death This practice may also result in undetected damage to the tire or rim that could result in failure of the tire in service Serious injury or death may result from explosion of the and rim wheel assembly due to heating the rim wheel Never rework weld braze or heat a wheel or rim nation Serie let V 10 ete ta Tee rmt Seer Bley oA Tee Bead uns Ats Bead Sx DUM MEY a Tre Sealants Baan Chaper 2 Page 28 The centrifugal forces created by a rapidly spinning tire can cause an explosion by literally tearing the tire apart These forces act on the complete tire structure and can be of such magnitude as to break the beads in addition to rupturing the tire Some vehicles are able to bring a tire to its centrifugal force failing point in just 3 to 5 seconds When stuck on ice snow mud or wet grass
15. dressings cleaners check with the tire manufacturer recommendations for cleaning tires See Cleaning Tires on p 27 Tire Service Life t is important to have tires in good operating condition thus tires may need to be replaced because of service conditions long before the tread is wom To determine if tires including the spare should remain in service it is recommended Chapter 2 Page 18 Common Examples of Tire Damage Run Fiat i ug Only Sidewall Separation Sidewall Separation Tread Crown Break 2 Bead Cut Tear Diagonal Cracking Ozone Weather Cracking that they be periodically inspected by a tire service professional during routine maintenance intervals like changes and tire rotations The service life of tires includes their overall condition and vehicle usage factors not just tread wear All of these factors should be taken into account when considering tire replacement Follow the vehicle and tire manufacturers specific recommendations if any regarding tire service and replacement in order to determine the age of the tire look for the last four digits of the DOT tire identification number see Chapter 1 Basic Tire Information for details For example a tire with a DOT tire identification number ending with the last 4 digits of 0309 indicates it was manufactured the 3rd week of 2009 ires that have been permanently removed from service should be rendered
16. height of the tire is 60 of the section width P225 60R16 97T SECTION HEIGHT Aspect RATIO SECTION HEIGHT Isecrion HEIGHT 60 SECTION wom SERVICE DESCRIPTION includes the load index numeric and speed symbol alpha character In the example above 97 is the load index is the speed symbol The numeric load index is a cade generally ranging from 50 129 that represents the maximum load carrying capacity Alpha speed symbols represent the speed capability see page 10 for more information RADIAL A tire with radial construction must shaw the word RADIAL on the sidewall A radial tire is also delineated by the character in the size designation MAX LOAD 730 kg 1609 Ibs AND 240 kPa 35 psi MAX PRESSURE COLD Indicates maximum load and maximum cold inflation pressure of the tire Sidewall markings are given in both metric and English units Follow tire inflation pressure recommendations on the vehicle tire placard certification label or in the owner s manual PLIES FABRIC INFORMATION The ply fabric information identifies the number of plies and type of cord materials in the tire tread and sidewall areas DOT MA L9 ABCD 0309 The DOT symbol certifies the tire manufacturer s compliance with US Department of Transportation US DOT tire safety performance standards Next to these letters is the tire identification number TIN also known as the tir
17. if one valve is at the 6 o clock position then the other should be at the 12 o clock position It may be necessary to install an extension hose with a bolt in clamp in metal valve stem to check inflation on an inside dual tire some applications It is recommended to use extension hoses with stainless steel reinforcement and external braiding as protection The ends of the hoses should be securely attached to the wheels so that they cannot come loose while driving If the holes in the wheels are too small or in the wrong place to be able to check inflation pressure on the inside tires this situation must be corrected before travel Determining Inflation Pressure With actual weights of the loaded RV acquired by weighing itis possible to compare them against the GAWR GVWR and tire capacities posted on the vehicle tire placard or certification label These actual weights are also what should be used to determine any increase in inflation pressure for the tires if required See How to Determine an RV s Actual Weight on p 53 Inflation pressure recommendations may also be determined based on the tire manufacturers specifications which define the amount of inflation pressure necessary to a given load These inflation pressures may differ from those found on the vehicle tire placard or certification label However never use inflation pressure lower than specified by the vehicle tire placard certification la
18. in the tire rotation Use one of the re rotation patterns illustrated inserting the full size spare at the right rear position Always check and adjust the inflation pressure of the size spare when incorporating it Into the rotation scheme Conditions Affecting Tread Wear Service Conditions Tread wear is affected by many different vehicle operating conditions Abnormal wear typically results fom a combination of unsatisfactory conditions and may make an accurate diagnosis of the cause s difficult It is important to identify the emergence of abnormal wear in its early stage and correct the cause before valuable tire treadwear is lost Most of the causes of abnormal treadwear can be corrected The causes can include excessive tire stresses due to driving habits road surfaces terrain and axle position Driving Habits The way a vehicle is driven has a great deal to do with tread wear and safety Observe posted speed limits and avoid hard stops starts and cornering In addition avoid potholes objects on the road and curbs such as hiting forcing the against the curb when parking The rate of wear Increases during hard comering at both high and low speeds due to scuffing caused by lateral forces particularly the front tires Hard acceleration or braking will also cause increased wear due to torque and weight transfer The tires with the most weight on them typically the front tires are doing t
19. lacing OE passenger tires Replacing passenger car tires with light truck tires will require a significant inflation pressure adjustment in order to carry the same load as the original equipment size Passenger tire load carrying capacity must be reduced by dividing by 120 for light truck applications For example P235 75R15 which has a maximum load capacity for passenger vehicle application 2028 Ibs For a light truck application using the formula the maximum load capacity would be 2028 1 10 1844 Ibs In addition to the important considerations listed above be sure to consult with vehicle manufacturer tire manufacturer and or a professional tire dealer for the appropriate replacement size adjusted NOTE Yherwise specified by Tire Replacement Guidelines inflation pressure and load rating for the vehicle See Important Considerations Inflation Pressure OE vs Replacement on p 45 There is a danger of serious injury or death if a tire of one bead diameter is installed on a rim or wheel of a different rim diameter ALWAYS replace a tire with another tire of exactly the same bead diameter as the diameter of the rim on which it will be mounted For example 16 tire goes on a 16 rim NEVER mount 16 tire on a 16 5 rim A 16 5 tire ONLY goes on a 165 rim NEVER mount a 16 5 tire on 16 rim While it is possible to pass a 16 diameter tire over the lip or flange of a 16 5 size diame
20. mix tread pattern types such as all terrain and all season Winter snow tires it is always preferable to apply winter snow tires to all wheel positions including duals to maintain vehicle mobility and control If winter snow tires are applied to the front axle of a vehicle winter snow tires must also be installed on the rear axle DO NOT apply winter snow tires only to the front axle This applies to all passenger and light truck vehicles including front wheel drive 4WD and AWD vehicles If winter snow tires are installed on the rear axle of any vehicle itis recommended but not required that they also be installed on the front axle Studded winter snow tires Studded winter snow tires have higher traction qualities under most winter weather conditions If studded winter snow tires are installed on the front axle of any vehicle studded winter snow tires must also be installed on the rear axle DO NOT apply studded winter snow tires only to the front axle If studded winter snow tires are installed on the rear axle of any vehicle it is strongly TE ae MA Tre Information Service ben Vl 42 picuon of Wn Sow Tres anf tief Win T Chapter 3 Page 41 recommended that they should also installed on the front axle Only if studded winter snow tires are installed on all wheel positions of a vehicle will optimum handling Characteristics be achieved Installing winter snow tires studded unstu
21. of ihe sidewall when inflated This results in an Indentation Since the belt plies reinforce the tread only the sidewalls are indented Sidewall indentations are a cosmetic characteristic and will not affect the performance of the tire If bulges rather than indentations appear on the sidewall or If there is any question conceming the sidewall appearance the tire should be examined by service professional ZZE ee RN Te eon eris Ri VII Saloa Inr al T Chapter 2 Page 27 Tire Explosions and Flammable Substances Inflation pressure in a tire represents tremendous Potential energy If improperly treated a tire can explode suddenly releasing the stored up energy which may result in serious injury or death Causes for tire wheel assembly explosions can include Tire damaged during mounting demounting Tire mounted on wrong size rim Improper mounting demounting procedures Use of flammable solvents during tire mounting or to seat beads Exceeding tie maximum pressure limitation Flammable liquids or vapors introduced into the tire including sealents and aerosol infators Welding heating or brazing an inflated tire wheel assembly Improper tube fitment and pinching of the tube between the rim and tire during inflation Re inflating a tire which has been run in an under inflated or over loaded condition Tire damaged in service or improperly repaired and reinflated Exceeding rim maximum pr
22. or speed symbol marked on the tire Tire Service Desci Load Index The load index is a numerical code associated with the maximum load a can at the speed indicated by its speed symbol under peche service conditions up to 130 mph 010 km h For speeds in excess of 130 mph 210 km ihe load the tire shall be reduced im accordance with selection For detailed information refer to the appropriate standards manual such as The Tire and Rim Association Yearbook for the vehicle load adjustment based on speed for V W Y and ZR rated tires Tres with the same load index regardless of the tire size may the same load but not always and they may require diferent inflation pressures In addition some tire sizes are available in more than one load index Refer to Table 1 for diferent examples The load index may not be used independently to determine replacement tire acceptibility for load capacity An equal or greater load index does not always correspond to equal or greater capacity at all inflation pressure settings particularly when Comparing P meti and European metic passenger Speed Symbol The speed symbol in a service description is also known as a speed rating See Table2 The speed symbol indicates the speed category at which the can carry a load corresponding to its load index under specified service conditions Speed ratings are based labor
23. peter to RMA Tire information Service Bulletin Vl TREADWEAR 600 TRACTION A TEMPERATURE B Treadwear traction and temperature are quality grades established and required by U S DOT under the Uniform Tire Quality Grading Standards UTQG These standards are only applicable to passenger car tires with some exclusions See page 11 for a more detailed explanation UTQG The following pertains to the Light Truck Sidewall shown in Figure 2 other markings on a light truck tire sidewall have the same meanings as those defined for passenger car tires LTA S 5RIG Load Range E This marking indicates that the size designation is for a metric light truck tire with a Load Range E The load range identifies the tire s load and inflation limits SERVICE DESCRIPTION Includes the load index numeric and speed symbol alpha character In the light truck sidewall illustration 120 11 the load indices for single dual application is the speed symbol The numeric load index is a code generally ranging from 50 129 that represents the maximum load carrying capacity the light truck example single and dual application load indices are listed Alpha speed symbols represent the speed capability See page 10 for more information MAX LOAD SINGLE 1380 kg 3042 Ibs AT 550 kPa 80 psi MAX PRESSURE COLD indicates the maximum load of the tire and corresponding maximum cold inflation pressure for that load when u
24. should be replaced For inflation pressures above 65 psi 450 kPa a high pressure valve must assembly When new tires are installed it is recommended to also replace components that are included in the TPMS valve replacement kit In addition whenever the sensor is disassembled for any reason install a new TPMS replacement Kit Always replace any damaged sensor be used The proper valve must be used for the particular tire wheel application Tire viheel assemblies that are equipped with a tire pressure monitoring system TPMS may have sensor that is attached to or is part of the valve conseua erie ire changing can be dangerous and should be done by trained personnel using proper tools and procedures Always read and understand any manufacturers warnings contained in owner s manuals on the equipment listed on websites and molded onto tire sidewalls Failure to comply with these procedures may result in faulty positioning of the tire and or rim parts and cause the assembly to burst with explosive force sufficient to cause serious physical injury or death Never mount or use damaged tires or rims For more information on tire mounting safety and procedures refer to the RMA wall chart Demounting and Mounting Procedures for Passenger and Light Truck LT Tires NEVER INFLATE BEYOND 40 PSI TO SEAT BEADS NEVER STAND LEAN OR REACH OVER THE ASSEMBLY DURING INFLATION Inspect both sides of the tire to be sur
25. that exceeded the capacity of one hitch or more tires on the vehicles Most of the weight was on the rear In a separate survey conducted by a tire company 4 out of 5 RVs had at least one under inflated tire a third of which were significantly under inflated and at risk of failure TIRE AND LOADING INFORMATION An under inflated tire cannot adequately carry the load placed upon it and will be subjected to excessive stress strain and heat build up which can lead to tre failure Also the under inflated tire in a dual pair can cause a weight transfer to the properly inflated tire resulting in it being over loaded which may lead to tire failure Often these significantly under inflated tires were the inner tires of dual pairs tires that are more difficult to see and service On average RVs were over loaded by over 900 pounds based on the RV manufacturer s Specifications Examples of RV Tire and Vehicle Placards Labels RV Tire and Vehicle Placards Labels In order to determine specifications for tire size tire inflation pressure and vehicle loading it may be necessary to consult different placards labels depending upon the vehicle type model year and manufacturer These placards labels include the following 18 consumen can also fid is imation in he AA boll V Tre Care and Sy Guide Chapter 4 Page 44 The type of important tire and loading information th
26. the inflation pressure Motorists should have their own gauge and keep it in the vehicle When To Check Inflation Pressure Check inflation pressure when tires are cold that is when the vehicle has been parked for at least 3 hours or has been driven less than one mile at moderate speed The inflation pressure all tres including the spare tire and inside duals should be checked with an accurate tire gauge at least once per month before each trip and each morning you drive during a trip This includes vehicles equipped with a Tire Pressure Monitoring System TPMS Maintaining proper inflation pressure maximizes fuel economy and optimizes overall tire performance Never bleed or reduce inflation pressure when tires are hot from driving as it is normal for pressures to increase above recommended cold pressures If a hot tire pressure reading is at or below recommended cold inflation pressure it may dangerously under inflated Under inflation and or over loading of a tire causes excessive heat build up and internal structural damage This may cause a tire failure including tread belt separtion even at a later date which can lead to an accident and serious personal injury or death Over loading an RV can have other serious safety consequences such as suspension or wheel failure increased braking distance or brake failure particularly steep grades and adverse vehicle handling stability Consult the
27. three 3 months so the flex area is changed tires from storage back to service Before placing stored tires back into service a tire service professional should conduct a visual and tactile inspection to be sure each tire is clean dry free of foreign objects and or does not show signs of damage See Tre Inspection Guidelines on p 16 Once mounted on a rim wheel the tire including the spare tire should be inflated to the recommended inflation pressure See Proper Tire Inflation on p 13 Cleaning Tires Clean tires with soap and water and a soft bristle brush or a shop cloth Treating tires with incompatible dressings or harsh cleaning agents will hasten oxidation and result in premature cracking Never use petroleum based products as dressings cleaners Use of a pressure washer or steam cleaner may be damaging to the tire Tire Sidewall Indentations The condition sometimes referred to as sidewall undulations is a common characteristic of radial lire construction see Figures 7 and 8 These indentations are more noticeable tire sizes with higher aspect ratios and or higher inflation pressures Figure 7 Sidewall Indentation n a radial tire the body ply cords run straight across the tire from bead to bead The joining of the ply material creates a narrow overlap of ply cords in the radial direction at each junction These overlapped ply cords slightly restrict the natural expansion
28. unserviceable and destroyed so no one else can use them Driving on damaged tires is dangerous damaged tire can suddenly fall leading to Situations that may result in serious personal injury or death Tires should be regularly inspected by a qualified tire service professional Tire Service Life is Not Determined by Chronological Age Tires are composed of various materials including rubber having performance properties essential to the proper functioning of the tire These component properties evolve over a combination of time service and Storage conditions For each individual tire this change is affected by many elements such as temperature storage conditions and conditions of use eg load speed inflation pressure impacts and road hazard injury to which a tire is subjected throughout its life Since service and storage conditions vary widely accurately predicting the service of any specific tire based on calendar age is not possible RMA is not aware of scientific or technical data that establishes or identifies a specific minimum or maximum service life for passenger and light truck tires However in some cases a tire vehicle manufacturer may make specific tire replacement recommendation regarding its products if so the consumer should consult the manufacturer with any questions with regard to following the recommendation Furthermore any such recommendation should not be considered a minimum s
29. vehicle tire placard certification label and owner s manual for the recommended vehicle load limits and tire inflation pressures Chapter 4 Page 50 this case immediately determine the cause and or have the tire checked by a tire service professional passenger light truck tire used on an RV may lose to 2 psi inflation pressure per month under normal conditions and 1 to 2 psi for every 10 degrees F temperature drop Truck bus tires may lose more due to their higher operating pressures If an RV tire continually loses more than 2 psi per month 4 psi for truck bus tires have it checked by qualified tire service professional Significant changes in altitude or temperature at which a vehicle will regularly operate will result in changes in inflation pressure and will require an inflation pressure check and adjustment Valves Metal valve caps with rubber seals are recommended for RV applications due to generally higher operating pressures The metal cap with a rubber gasket provides a seal that a plastic valve cap not provide Boltin clamp in metal valve stems recommended for RV applications They MUST be used when valve extensions are installed because the extra weight of the extension or hose can distort rubber stems and ultimately cause loss of inflation When dual tires are mounted on a vehicle they should always be installed with the valve stems 180 degrees apart for example
30. 33 Inspection Procedures to Identify Potential Sidewall Zipper Ruptures in Steel Cord Radial Truck Bus and Light Truck Tires Chapter 2 Page 34 Tire Retreading While retreading tires is predominantly a practice used for commercial truck and bus tires there are some companies that retread light vehicle tires Note that it takes special equipment and expertise to retread passenger car and light truck tires For more detailed information on retreading passenger and light truck LT tires refer to the RMA Shop Bulletins for tie reteading and tire repairing Chapter 2 Page 35 Overview The purpose of this chapter is to provide tire industry recommended guidelines and important safety information when replacing tires for light vehicles 13 While this chapter is intended to outline general guidelines and considerations for tire replacement it is not all inclusive Questions pertaining to specific products and or vehicle fitments should be addressed to the vehicle manufacturer tire manufacturer or tire dealer Because tire technology continually evolves visit the RMA web site at www ma org for current information 8 5 I T n SoA WERE cap TRE UO RS MSSE m es ALWAYS refer the vehicle manufacturer s recommendations and The Right Tire for the Vehicle When tires need to be replaced do not guess what tire is right for the vehicle For the answer refer t
31. Care and Service of Passenger and Light Truck LT Tires Including Tire Replacement Guidelines and Recreational Vehicle Applications RUBBER manufacturers association Rubber Mantacturers Associaton August 2011 Care and Service of Passenger and Light Truck LT Tires Including Tire Replacement Guidelines and Recreational Vehicle Applications Table of Contents Chapter 1 Basic Tire Information overview Chapter 1 page 2 Construction and Terminology Chapter 1 page 2 Size Designations Chapter 1 page 3 The Sidewall Story Chapter 1 page 6 Service Description Chapter 1 page 10 Uniform Tire Quality Grading Standards for Passenger Car Tires Chapter 1 page 11 Sidewall Marking for Retread Tires Chapter 1 page 11 Chapter 2 Tire Care and Service overview Chapter 2 page 13 Proper Tire inflation Chapter 2 page 13 Tire Loading Chapter 2 page 16 Sudden Ride Disturbance or Vibration Chapter 2 page 16 inspection Guidelines Chapter 2 page 16 Tire Service Life n Chapter 2 page 18 Tire Rotation Chapter 2 page 20 Conditions affecting Tread Wear Chapter 2 page 22 Proper Tire Repair Chapter 2 page 24 Passenger and Light Truck Used Tires Chapter 2 page 26 Spare Tire Maintenance Chapter 2 page 26 Tire Storage Recommendations Chapter 2 page 26 Cleaning Tires Chapter 2 page 27 Sidewall ndentations Chapter 2 page 27 Explosions and Fla
32. INFORMATION 0811 Chapter 1 Page 1 Overview Tires are designed and manufactured to meet strict governmental requirements internal company Standards vehicle performance characteristics and consumer expectations Modern tire technology blends a unique mix of chemistry physics and engineering to give consumers a high degree of tire performance that provides safety reliability efficiency long wear and comfort Tires are manufactured inspected and tested to assure consumer safety and satisfaction As result properly cared for tires will provide a longer service Tire Construction and Terminology Nearly all passenger and light truck tires are radial ply construction that provides sidewall flexibility with body cords that run across the tire nearly perpendicular to the beads Radial tires have belt plies With steel and or other cords laid diagonally under the tread to stabilize and reinforce the tread area during contact with the road Passenger Tire vs Light Truck Tire Construction Differences between passenger and light truck construction are due to their different uses and operating conditions compared to passenger tires light truck tires usually operate at higher inflation pressures and carry greater loads on a regular basis Light truck tires are typically designed for more severe service such as in commercial vehicle applications or for off road use In order to meet these performance nee
33. R limitations are achieved 2 Weigh the travel trailer while attached to the towing vehicle The towing vehicle should not be on the scale The result is the weight exerted on all of the trailer tires Subtract this weight from the overall weight in Step to determine longue weight 3 With the trailer still attached to the towing vehicle each wheel position should be weighed separately to be sure each tire is not over loaded If an over load condition exists on any wheel position trailer contents must be redistributed or removed 4 The individual wheel positions particularly the rear positions on the towing vehicle should also be weighed while the trailer remains attached This is especially important on Sth wheel applications If an over load condition exists on the towing vehicle trailer contents must he redistributed or removed and Steps 2 through 4 must be repeated Refer to the diagrams on p 55 to 57 to record your results RV Tire Inspection Guidelines In addition to maintaining inflation regularly inspect the tires tread and sidewalls for irregular tread wear cracking scrapes bulges cuts snags foreign objects other damage resulting from use Itis recommended that RV tires including the spare be periodically inspected by a tire service Professional including an inspection before every travel season and during routine RV maintenance intervals like oil changes and tire rotations
34. Wgrmuk Ta ih thes 3 E European Commercial Metric C Type maar pA vag ameet ranor Es ST Type Special Trailer Wai a ato eget NOTE Tre designations witout ence descptons are no longer n general 18s common prz Meri and European Mti are sizes to be placed n pickups vans sport vehicles and other vehicles that might be peccet as a ight tuck Check o see which of tre the veide For more see Chapter 3 hie Replacement Guanes tH Tres designad spel for traer sem hgh sence Chapter 1 Page The Sidewall Story Ties have very useful information molded onto their sidewall It shows the brand and model name of the ire its size whether it is tubeless or tube type the maximum load and the maximum inflation safety waring s and much more Figures 1 and 2 on p 8 9 show typical information on the sidewall of passenger car and light truck tires P225 60R16 97T Size marking and Service Description load index speed symbol for a P Metric speed rated passenger An aspect ratio number typically ranging from 30 to 80 in tire size designation indicates the ratio of the tire section height to section width Aspect ratios are also referred to as series and profile numbers In the example below of a tire with an aspect ratio of 60 the section
35. aintain mobility the consumer will need to acquire additional equipment such as a spare tire new rim wheel assembly hand jack etc Vehicle TPMS visual displays audible alarms and logic designed for runflat operation may be affected Vehicle handling stability and performance can be affected Vehicle owner s manual reference regarding OE runflat tire fitment may no longer apply standard practice any replacement tires should be of the same size inflation pressure load carrying capacity and speed rating noted on the vehicle tire placard Replacing Conventional Tires with Runflat Tires Depending on the specific tre Vehicle wheel TPMS and other factors runflat tires may be acceptable replacements for conventional tires However a vehicle or tire manufacturer may advise against the application of certain runflat tires to certain vehicles that were not originally equipped with runflat tires Therefore the vehicle and tire manufacturers must be consulted on their tire replacement recommendations for specific vehicles and runflat tires If conventional tires are to be replaced by runflat tires follow the same tire replacement recommendations established for conventional tires that include selecting the proper tire size s and meeting inflation pressure capacity load carrying capacity and speed rating requirements Refer to the vehicle and tire manufacturers tire replacement recommendations and the vehicl
36. an have an adverse ellect on suspension systems gear ratios transmission and tire treadwear If single tire replacement is unavoidable itis recommended that the single new tire be paired with the tire that has the deepest tread and both be placed on the rear axle Placing greater traction on the rear axle on wet surfaces is necessary to prevent possible oversteer condition and loss of vehicle stability Tire Rim Wheel Selection Tires should only be mounted on approved rim widths for more information refer to tire manufacturer product literature for rim width specifications Figures 10 and 11 illustrate examples of series profile and rim width respectively Figure 10 Serles Profile Example m L cos ae Figure 11 6 inch Rim Width Example DSM Chapter 3 Page 42 Always check to be certain that the diameter designation for both tire and rim are the same For example a P235 75R16 tire must be mounted 16 inch rim see the rim WARNING on p 39 If replacement tires or rims wheels are of a different size from the OE be sure that the outside circumference of all four tires is within the accepted tolerance of the vehicle manufacturer Some rims wheels may not allow correct bead seating unless the OE tire is used Consult vehicle manufacturer Never exceed the maximum pressure and or load capacity of the rim wheel High pressure T type temporary spare tires sho
37. apid and or abnormal wear Improper vehicle handling and decreased fuel economy Over inflation can also result in rapid and or abnormal tread wear decreased traction and premature wear of suspension components Improper tire inflation may cause a tire failure including tread belt separation even at a later date which can lead to an accident and serious personal injury or death Check and adjust tire pressure including the spare at least Chaper2 Page 22 per month with a pressure gauge see Proper Tre Inflation on page 13 Vehicle Wheel Vent Ifthe vehicle wheels are not properly aligned tires will experience stresses as if they were constantly cornering This will cause increased and abnormal read wear A qualified mechanic should correct misalignment of wheels Front wheel drive vehicles and those with independent rear suspension require special attention with alignment of all four wheels For any vehicle four wheel alignment can identify problems such as dog tracking when the rear tires do not follow in the paths of the front tires This can also result in abnormal tread wear The vehicle alignment geometry should be checked periodically as specified by the vehicle owners manual or if misalignment is suspected Lack of Tire Rotation Tire rotation procedures are established to equalize the tread wear for each tire to prolong tread By regularly changing a tite to another position on the vehicle
38. are permanently marked on the sidewall with DOT R and followed by 7 to 13 character tire identification number TIN If the original new tire was certified by the manufacturer to the applicable safety standards and regulations the original DOT certification mark and the new tire TIN may remain on the tire casing after retreading along with the retreader s TIN Ia speed rated tire is retreaded the speed rating is no longer valid Chapter 1 rage Tire and Service CHAPTER 2 OF A 4 CHAPTER SERIES TIRE CARE AND SERVICE eSPLT2 0811 Chapter 2 Page 12 Overview Tires are designed and manufactured with advanced technology and great care to provide thousands of miles of excellent service For maximum safety performance and service they must be maintained properly THE MOST IMPORTANT FACTORS IN TIRE SAFETY PERFORMANCE AND SERVICE LIFE ARE PROPER TIRE SIZE TYPE AND LOAD CAPACITY OR LOAD RANGE PROPER INFLATION PRESSURE PROPER VEHICLE LOADING REGULAR TIRE ROTATION REGULAR INSPECTION PROPER TIRE VEHICLE CONDITION ALIGNMENT AND MAINTENANCE GOOD DRIVING HABITS This chapter will address these and other factors relative to the care and service of passenger cat and light truek tires Driving on tires with improper inflation pressure is dangerous Under inflation causes excessive heat build up and internal structural damage Over inflatio
39. atory tests that relate to performance on the road but are not applicable if tires are underinflated overloaded wam out damaged or altered Although a tire may be speed rated RMA does not endorse the operation of any vehicle in an unsafe unlawful manner Furthermore tire speed ratings do TABLE 1 Examples of Tire Size and Load Index Value Differences TABLE 2 Speed Symbols Speed Speed Speed ing Category Symbol ap kg u a 12 a ta T0 x ue 170 5 180 190 v u fis 200 ET Y f w w iar zm x ise 300 LJ suc tray tes hy ge td pay dnd on frs such San pesar bal canti wat ad ing tre hang speed capi 149 ph BA oA may at Be tre monitus delen alea or res ag a sped pati above 186 ph GOO LV 2 a as b be deinen and uc uk a serae mr he tre manufacture ped capat when there oo erie c eod mara on re ps macspeed gt 149 mph const te t mat speed Mag FIT AGAM 930 man oa mel EN speed 2 164 ph PUSAAVRIT ma 186 ph consi Load Copaci Sat Varius Pressumes Sue Toad index
40. ay or at higher speeds whether on or off road Using Nitrogen Inflation Nitrogen may be offered an alternative to air for tire inflation Nitrogen is am inert non flammable gas basically nothing more than dry air with oxygen removed air contains about 78 nitrogen Because of its inert properties nitrogen is often used in highly specialized service applications and or demanding environments For instance aircraft mining and commercia heavy applications use nitrogen to help reduce the risk of internal combustion fire if the brake rim wheel components overheat Also dry nitrogen is used in professional racing to help reduce variation in Inflation pressures caused by moisture where even small differences in pressure can affect vehicle handling at the extreme limits of performance For normal tire service applications nitrogen inflation is not necessary However nitrogen inflation is permissible as its properties may Contribute to minor reductions in inflation pressure loss Nevertheless several other sources of pressure leaks such as punctures tire rim interface bead valve valve rim interface and the wheel may negate the benefit of nitrogen If the tire inflation pressure is below the pressure specified on the Vehicle tite placard certification label or owner s manual the tire must be re inflated whether with or nitrogen to the proper inflation pressure Do not operate tires under Inf
41. bel or owner s manual Nor should inflation pressure exceed the maximum pressure molded on the tire sidewall Load and cold inflation pressure imposed on a rim wheel must not exceed the rim wheel manufacturer s recommendation even though the tire may be marked for a higher load and inflation Matching radial tires with rim wheels must be done with care Older rims wheels may not be approved for use with radial tires Consult the RV or the rim wheel manufacturer for acceptable rims wheels for a specific radial tire 20 eke to A Tee Information Service ulti Vol 40 ks pe ie Re Passenger an Let Huck Tes cdg Tues nsn Tre ahe Chapter 4 Page 51 Proper RV Tire and Vehicle Loading Tires used on RVs are typically subjected to a greater variety of loading conditions often at or near maximum loads than automobile light truck and truck applications Many RVs end up over loaded simply because people put too many things in them There is often no quick way to determine the weight of the items loaded so there is a temptation to keep loading until most of the available space is filled Most people tend to load by volume when weight is far more important Unfortunately these circumstances will tend to exceed the load carrying capacity of the tires or axles long before everything is on board The only way to determine if the vehicle is aver loaded is to have it weighed See How to Determine Actual Weight on page 53 I
42. cement tires or as equipped on a used vehicle Once tires are applied to a vehicle and put into service this includes spare tires they are considered used There is a potential risk associated with the installation of used tires that have uncertain or unknown history of use maintenance storage conditions Such tires may have damage that could eventually lead to tire failure Driving on damaged tires is dangerous A damaged tire can suddenly fail leading to situations that may result in serious personal injury or death Tires should be regularly inspected by a service professional qualified tire Not all tire damage that can lead to tire failure is outwardly visible For instance improper repairs damage toa tire s innerliner can only be observed by inspecting the inside of the tire demounted from the wheel A qualified tire service professional should inspect the internal and external condition of the used tires prior to application In the case of a used Tire Replacement Guidelines vehicle purchased by a consumer the only way to determine the condition of its tres is to have them demounted by a tire service professional for the same type of inspection 17 nettene to RA Tre Information Service Vo 48 Passenger and ih Mack Led hes Chapter 3 Page 46 4 IN A 4 CHAPTER SERIES RECREATIONAL VEHICLE APPLICATIONS CSPLTA OBII Chapter 4 Page 47
43. d check the surface and the valve for the source of the eakts by using water or soap solution prior to demounting the tre from the Tim Mark the injured area and totally deflate the tire Then remove the tire from the wheel being careful to avoid further damage to the tire particularly to the bead area Perform a complete internal inspection For RV s equipped with dual tire assemblies duals if one of the dual tires becomes significantly underinflated or flat the other tire will the load for both tires resulting in an overloaded condition Both tires should be inspected by a tire service professional for damage See Tire Inspection Guidelines on page 16 in Chapter 2 Always read understand and follow the RMA puncture repair wall charts Puncture Repair Procedures for Passenger and Light Truck Tires or Puncture Repair Procedures for Truck Bus Tires These wall charts cover the proper repair procedures for passenger and light truck tires through Load Range E and truck bus tires load range F and above Never repair passenger or light truck tire with an injury that is greater than 1 4 inch 6mm in diameter Never repair a load range F and above truck bus tire with an injury that is greater than 3 8 inch 10mm in diameter not repair an injury outside the puncture repair area as shown in Figure 13 Figure 13 Puncture Repair Area Puncture repairs are to the tread area a
44. d proper repairs Such products may be flammable and potentially explosive may damage the tire may void the tire manufacturer s warranty and may interfere with or damage pressure monitoring system sensors Consult the tire manufacturer s service recommendations and warranty policy See Tire Explosions and Flammable Substances on p 28 Chapter 2 Page 25 Passenger and Light Truck Used Tires This information pertains to used passenger and light truck tires installed as replacement tires or as equipped on a used vehicle Once tires are applied to a vehicle and put into service this includes spare tires they are Considered used There is a potential risk associated with the installation of used tires that have uncertain or unknown history of use maintenance or storage conditions Such tires may have damage that could eventually lead to tire failure Not tire damage that can lead to tire failure is outwardly visible For instance improper repairs damage to tire s innerliner can only be observed by inspecting the inside of the tire demounted from the wheel A qualified tire service professional should inspect the internal and external condition of the used tires prior to application In the case of a used Vehicle purchased by a consumer the only way to determine the condition of its tires is to have them demounted by a tie service professional for the same type of inspection Driving on
45. damaged tires is dangerous A damaged can suddenly fall leading 10 situations that may result in serious personal injury or death Tires should be regularly inspected by a qualified tire service professional Spare Tire Maintenance Spare tire full size and temporary spare inflation pressure should be checked monthly and before any long trips Use an accurate gauge temporary spate tires require 60 psi 420 kPa When adjusting inflation pressure in T type tires do so in small amounts since the is smaller and the pressure level changes rapidly Do not over inflate Inspect the spare tire rim wheel periodically Le during tire rotation interval for any visible damage to the or corrosion on the wheel 1f the vehicle has a matching full size spare tire it is recommended that it be included in the tire rotation Always check and adjust the inflation pressure of the full size spare when incorporating it Into the rotation scheme Type temporary spare tires should only be used with rims wheels specifically intended for them Rims wheels intended for use with T type tires should not be used with any other types of tres temporary spare tite and wheel assembly should never be used on a vehicle with which itis compatible Never use more than one temporary spate tire at a time Tire Storage Recommendations Stored tires should be protected against environmental effects such as s
46. dded only on the front axle may cause the vehicle to experience adverse handling characteristics This may result in an accident which could cause serious injury or death Some states prohibit the use of studded tires and many states have seasonal limitations on their use Before installing check with state and local regulations Replacing Less Than Four Tires When replacing tires on a vehicle it is recommended and preferred that all four tires replaced at the same time for continued optimal vehicle performance However for those cases where this is not feasible below are some general guidelines to consider when replacing less than four tires for a light vehicle whether it is one or two tires Also see Tire Mixing on p 41 If the vehicle manufacturer has alternate recommendations always follow their recommendations Replacing Two 2 Tires When a pair of replacement tres is sclected in the same size and construction as those on the vehicle the two newer tires should be installed on the rear axle Generally new tires with deeper tread will provide better grip and evacuate water more effectively which is important as a driver approaches hydroplaning situations Placing greater traction on the rear axle on wet surfaces is necessary to prevent a possible oversteer condition and loss of vehicle stability Tire Replacement Guidelines Replacing One 1 Tire Replacing a single tire on vehicle c
47. dewalls for irregular tread wear cracking scrapes bulges cuts snags foreign objects or other damage resulting from use Lis recommended that tires including the spare be periodically inspected by a tie service professional during routine maintenance intervals such as oil changes and tire rotations Remove any stones glass foreign objects etc embedded in the tread to prevent damage Even minor damage can lead to further injury and eventual tire failure Also it is good practice to check between dual tire wheel assemblies for foreign objects like large rocks that may have become lodged between the tres especially after off road service Tires with excessive cracking on the tread or sidewall s should be removed from service This is typically caused by under inflation over loading Chapter 2 Page 16 improper storage and or improper long term parking Replace tires when worn to 2 32 1 6 mm depth remaining anywhere on the tread face For vehicles with a GVWR in excess of 10 000 pounds 4 536 kg federal regulations state that tires on the front axle should be removed when worn to 4 32 3 2 mm tread tread wear indicators or wear bars which look like narrow strips of smooth rubber across the tread will appear on the tire when the tread is wom 102 327 1 6 mm see Figure 4 When a wear bar is Mush with the tread surface the tire is worn out and itis time to replace it
48. ds light truck tires may have additional components layers and heavier duty materials As a result light truck tires tend to be heavier than passenger tires Rubber Compounding Rubber compounding is a complex science of mixing different raw materials together to produce rubber compounds with specific characteristics Rubber compounds differ due to their location and functional purpose in the tire Example Outside tread compound provides traction and treadwear characteristics although rubber is the main material used for making tires there are a number of other materials used as well These materials are combined with specific rubber compounds in the different components that make the construction Tire Cutaway Typical Construction Features Body Ply Most tires have one or two body plies each typically comprised of polyester rayon nylon cords within a rubber layer Body plies function as the structure of the tire and provide the strength to contain the inflation pressure Bead Tire bead bundles usually strands of wire secure the to the wheel Belts typically two belts with steel cords laid at opposing angles Belts provide stability to the tread area of the tire which contributes to wear handling and traction Innerliner A rubber compound used to retain the inflation pressure inside the Sidewall rubber compound used to cover the body plies on the sides of the
49. e serial number The first two digits are the factory code indicating where the tire was made The last four digits are numbers identifying the week and year of manufacture Example 0309 means third week of the year 2009 Chapter 1 page 6 Other characters in between the first four and last four are optional manufacturer s codes for tire type make elc AI tires produced after September 2009 must have the full TIN on the intended outboard side of the tire and at least a partial TIN the other sidewall The partial TIN does not include the date code Prior to the year 2000 the last three digits of the TIN represent the date code Example 025 is the second week of 1995 For the 1990 1999 decade some tires may be marked with a symbol such as triangle after the TIN date code Beginning in the year 2000 the last four characters are numbers Identifying the week and year example 0309 means the third week of the year 2009 DOT TIN Example MA L9 ABCD 0309 MA 49 ABCD 0309 TUBELESS The tite must be marked either or tube type M S This mark is commonly found on all season tires In several formats the letters M and indicate the tire is intended for limited mud and snow service Other formats include 5 M S oU M amp S T boire Ec P744 ERE E erp a elo ol a mounah Wi evite pru
50. e manufacturer s loud and ination table or the eval of the es mounted en the vehicle Nol 2 I vehicle has dui ead dul apc om an ay to cll dual ad capacity Chapter 4 Page 55 Weighing a Tandem Axle Recreational Vehicle RV To Obtain Individual Axle and Gross Vehicle Weights sre stepid 00 Seale Weight be m m Bam Geru omy From Owners be bs bs bs Ma cun E E own STEP 20 STEP 2 STEP 20 z 1 one Side bs bbs bs sele Weight Sap aa EZ a Rouen Qoa Calculate Other tos be m SideWeight Tre Load bs m Gener psi Weighing a Pulling Vehicle and Travel Trailer Pulling Vehicle To Obtain Individual Axle and Gross Vehicle Weights STEP 1a STEP 1b STEP 1e Calculated Scalo Weight Ibs Ib Ibs pope Bp eW Sip Te Paar le From Owner s Je Ibs Manual own p Mk Y vehicle as duais rod dual oem mp cse cpi Chapter 4 Page 56 Weighing a Pulling Vehicle and Travel Trailer continued To Obtain Individual Wheel Position Weights
51. e photo above is an example of a tire that was operated in an underinflated condition with puncturing object that caused dangerous non repairable damage to the innerliner and body ply material This type of damage would not have been visible from the outside of the tire Every tire must be removed from the wheel for an inspection and to assess repairability Parking an RV When parking an RV for extended periods of time it is important to make sure the vehicle is as level as possible not only for convenience and comfort Purposes but also to avoid over load tire conditions due to weight transfers On RVs without built in leveling devices it is customary to the low wheel positions Care must be taken to ensure that the tires are fully supported when using blocks Chapter 4 Page 60 The load on the tire must be evenly distributed the block and in the case of duals evenly distributed blocks for both tires If this isn t done properly sidewall casing cables may be damaged which may lead to premature sidewall fatigue and ultimate tire failure Refer to Figure 14 for blocking methods for Rvs Figure 14 Tire Blocking Methods Correct Singles me Passenger and Light Truck Used Tires This information pertains to used passenger and light truck tires installed as replacement tires or as equipped on a used vehicle Once tires are applied to a vehicle and put into s
52. e placards labels includes the following 1 Gross Vehicle Weight Rating GVWR 2 Gross Axle Weight Rating GAWR for each axle 3 Tire and whecl rim sizes 3 Recommended cold tire inflation pressures Consult the vehicle owner s manual for additional tire and loading information Follow the vehicle tire placard certification label and owners manual for recommended vehicle load limits and tire inflation pressures When replacing RV tires refer to the certification label for the tire size s and load capacity load index recommended by the RV manufacturer If replacing with a tire size other than shown on the certification label consult the RV manufacturer or tire service professional for recommendations Using the wrong tire size or load range load index can lead to tire failure Vehicle modifications such as lift kits and other suspension alterations and or use of tires not recommended by the vehicle tire manufacturer can adversely affect vehicle handling and stability Tires specifically designed for travel trailer use in highway service have an Special Trailer molded on the tire sidewall ST225 75RI5 or ST235 80RI6 ST tires have different load capacity characteristics Therefore ST tires should not be replaced with any other type tire RV Tire and Vehicle Load Limits TO avoid overloaing tires maintain the proper lation pressure and never exceed the volcb s sss axle weight ratings CAWR or the Gro
53. e that the beads are evenly seated If tire is mounted a machine that does not have a positive lock down device to hold the wheel inflation should be done in a safety cage or other restraining device If both beads are not properly seated when pressure reaches 40 psi completely deflate the assembly reposition the and or tube on the rim relubricate and reinfate Inflating beyond 40 psi inflation pressure when trying to seat the beads is a DANGEROUS PRACTICE that break a tire bead or even the rim with explosive force possibly resulting in serious injury or death After the beads are fully seated pressure may be increased above 40 psi to operating pressures as shown on the vehicle placard but not to exceed the maximum molded on the tire sidewall Chapter 2 page 30 There is a danger of serious injury or death if a tire of one bead diameter is installed on a rim or wheel of a diferent rim diameter Always replace a tire with another of exactly the same bead diameter as the diameter of the rim on which it will be mounted For example a 16 tire goes on a 16 rim Never mount a 16 on a 1657 rim A 165 goes on a 16 5 rim Never mount a 165 on a 16 rim While itis possible to pass a 16 diameter over the lip or flange ofa 16 5 size diameter rim it cannot be inflated enough to position itself against the rim flange If an attempt is made to seat the tire bead by inflating the tire bead
54. e tire placard certification label and or owner s manual In addition note the following recommendations The vehicle must have an operational TPMS If not originally equipped with a TPMS a system must be retro fit to the vehicle 5 Do not mix tires with incompatible runflat Service ln V 47 General emat n Se Supporting Chapter 3 Page 40 technologies a vehicle for example all tires should be the same type of self supporting runflat The wheels must be the recommended size rim contour such as extended hump example EH2 and EH2 marked rims and must be compatible with the runflat tires and any TPMS sensors The Inflation pressure recommendations for runflat tires are the same as those for conventional tres that have the same size code load index and speed rating Never mix runflat tires with conventional tires unless in an emergency situation on a limited temporary basis See Emergency Temporary single Conventional Tire Replacement above Tire Mi It is recommended that all four tires be of the same size load index speed rating and construction radial non radial In some cases the vehicle manufacturer may require different sized tires for either the front or rear axles NEVER mix P Metric or European Metric passenger tires with light truck LT sized tires on the same vehicle Match tire size designations in pairs on an axle except for temporary use of a spare t
55. eat the tire bead by inflating the tire bead will break with explosive force and could cause serious injury or death Rims of different diameters and tapers cannot be interchanged The following diagram illustrates the difference between rims of two different tapers and diameters m The following diagram shows how beads of a 16 tire will not seat on a 16 5 rim The beads cannot be forced out against the rim flanges by using more air pressure because this will break the beads and the tire will explode with force sufficient to cause serious injury or death LI tires from storage back to service If tires are mounted on a stored vehicle Store the vehicle such that all weight is removed from the tires If vehicle weight cannot be removed unload the vehicle to minimize the weight Maintain the recommended tire inflation pressure including the spare The surface where parked stored should be firm reasonably level well drained and clean The vehicle should be moved every three 3 months so the tire flex area is changed Before placing stored tires back into service a tire service professional should conduct a visual and tactile inspection to be sure each tire is clean dry free of foreign objects and or does not show signs of damage See RV Tite Inspection Guidelines on p 54 Once on a rim wheel the tire including the spare tire should be inflated to the recommended inflation pressure S
56. ed on the front and rear axles and these different sized tires have rotation restrictions For these special cases check the recommendations in the vehicle owner s manual for proper rotation When tires are rotated the inflation pressures must be adjusted for the tires new positions in accordance with the vehicle manufacturers Chapter 2 page 20 Figure 5 Typical Rotation Patterns When Tires are the Same Size and Front Wheel D Al Vehicles wth Full Size 0 mor Vehicles Tie FRONT Front Whee Drive Rear and Four Ali Vehicles Vehicles eel Drive Vehicles FRONT th Dual Rear Wheels Sh Tre Rotation 8 Front 0 FRONT MOM 5 Chapter 2 Page 21 recommendations see the vehicle tire placard certification label or owners manual Under inflation may result in rapid and or abnormal readwear improper vehicle handling and decreased fuel economy Over inflation can also result in rapid and or abnormal tread wear decreased traction and premature wear of Suspension components Improper tire inflation may cause a failure including tread belt separation even at a later date which can lead to an accident and serious personal injury or death See Proper Tire Inflation on p 13 Do not include a Temporary Use or T type spare tire in any of these rotation patterns If the vehicle has a matching full size spare tire it is recommended that it be included
57. ee Proper RV Tire Inflation on p 50 Chapter 4 Page 62
58. er perform a tire repair on the wheel Never use only a plug stem Never use only a patch Chapter 2 Page 24 Tire changing can be dangerous should done by trained personnel using proper tools and Procedures Always read and understand any manufacturers warnings contained in owners manuals on the equipment listed on websites and molded onto sidewalls Failure to comply with these procedures may result in faulty positioning of the tite and or rim parts and cause the assembly to burst with explosive force sufficient to cause serious Physical injury or death Never mount or use damaged tires or rims For more information on mounting safety and procedures refer to the RMA wall chart Demoun ng and Mounting Procedures for Passenger and Light Truck LT Tires Vehicle Original Equipment Temporary Tire Mobility Kits A temporary tire mobility kit may be supplied by the vehicle manufacturer as an alternative to a spare or runflat tire in passenger car and light truck applications The temporary tire mobility kit is normally comprised of a puncture sealant and a small ait compressor or container of propellant Use of a temporary tire mobility kit Is not considered a repair to the tire Orly provides temporary solution to promptly reach a service location for professional inspection and possible repair of the affected tire Refer to tire manufacturer for specific guidelines regarding
59. ervice this includes spare tires they are considered used There is a potential risk associated with the installation of used tires that have uncertain or unknown history of use maintenance or storage conditions Such tires may have damage that could eventually lead to tire failure Not all tire damage that can lead to tire failure is outwardly visible For instance improper repairs or damage to a tire s innerliner can only be observed by inspecting the inside of the tire demounted from the wheel A qualified tire service professional should inspect the intemal and external condition of the used tires prior to application In the case of a used vehicle purchased by a consumer the only way to determine the condition of its tires is to have them demounted by a tire service professional for the same type of inspection Driving on damaged tires is dangerous A damaged tire can suddenly fail leading to situations that may result in serious personal injury or death Tires should be regularly inspected by a qualified tre service professional Stoi g RV Tires Stored tires should be protected against environmental effects such as sunlight high heat ozone and other potentially damaging conditions Store tires where the area is clean dry and well ventilated but with a minimum of circulating Store tires in an area with temperate ambient conditions mild temperatures shaded or dark Store tires raised off a
60. ervice life for the tire Tire Rotation Before rotating tires always consult the vehicle and or tire manufacturer for specific recommendations regarding rotation The purpose of regularly rotating tires is to prolong tread life and promote more uniform tread wear for all tires a vehicle If no rotation period is specified tires should be rotated every 5 000 to 8 000 miles or per the manufacturers recommendations ar at any sign of uneven wear The first rotation is the most important Going for extended mileage where the tires are not rotated can result in a situation where pair of tires wears prematurely and unevenly If tires show uneven tread wear check for and correct any misalignment imbalance or other mechanical problems before rotation Any vehicle showing a tendency for wear differential should have tires rotated more often Always consult the vehicle and or tire manufacturer for specific rotation instructions Many vehicle manufacturers recommend replacing all ties on the vehicle at the same time This makes rotation even more important for maintaining uniform tread depth and optimum tread wear of the entire set n the absence of vehicle manufacturer rotation recommendations follow the rotation patterns in Figure 5 Note that certain types of ties cannot be rotated in the manners shown Such tires may include directional and asymmetrical tires Also some vehicles may have different sized tires mount
61. essure limitation Brake over heating Avoid flammable vapors inadvertently being pumped into tire when the tire is inflated Do not use alcohol methanol dry gas or any other flammable material in the compressor tank to prevent freezing or condensation Do not store flammable solvents or rubber cements near the intake of the compressor Do not clean the compressor Intake screen flter with flammable solvents such as gasoline Do not use a battery charger near the compressor intake This can result in hydrogen gas being drawn into the compressor Locate compressor indoors where freezing will not occur and in an area by itself away from operations such as tire repairing battery charging etc Each day open the bleed valve on the tank to expel moisture Add filter trap or dryer to the compressor to remove moisture Aftermarket Sealants Infiators Flammable propellants and or liquids in aftermarket sealants or aerosol inflators may cause to explode under certain circumstances Never introduce flammable substance into Tire service professionals should assume that any aftermarket product used to seal or inflate a tire is Tammable I addition to following proper demounting procedures see p 29 take the following precautions Keep the tire away from heat flame sparks or other ignition sources Use tools with caution particularly tire irons reamers and hammers to avoid
62. fender wells around brake components shock towers and other suspension components These wheel positions must be checked for full suspension jounce and rebound Vehicle Modifications Lift kits and other types of suspension alterations or use of tires not approved by the vehicle or tire manufacturer can adversely affect vehicle handling and stability State Local Laws Check to be sure that the fitment complies with any state local regulations Important Con erations Inflation Pressure OE vs Replacement Fitment of a new tire other than the OE size on the vehicle may require a higher inflation pressure than specified on the vehicle tire placard to adequately the load If so the installer should inform the owner of the new required inflation pressure The installer should also place a sticker or decal next to the vehicle tire placard showing the new tire size and inflation pressure requirements for future reference Never inflate a tire below the recommended pressure shown on the vehicle s tire placard Standard Load SL Reinforced Extra Load XL Fitments Some passenger tires have extra load capabilities Generally these tires will have XL or Extra Load or Reinforced molded on the sidewall of the tire Special care should be exercised when considering reinforced or extra load tires as substitutes for standard load SL tires A reinforced or XL tire offers higher max
63. flation and or over loading of a tire causes excessive heat build up and intemal structural damage This may cause a tire failure including tread belt separation even at a later date which lead to an accident and serious personal injury or death t is important to inspect tires for under inflation and or aver loading damage such as internal tire separation heat discoloration cracking rim flange grooving and localized accelerated treadwear spot Wear Punctures cuts snags etc can lead to further damage if not repaired in time The tire must be demounted and carefully inspected to determine whether it is repairable Some road hazard damage may result in gradual inflation pressure loss If not corrected as soon as possible such damage can ruin tires that could otherwise have been repaired For information on proper tire repair see Proper Tire Repair on page 24 Impact Damage Impact damage to the tite may intially show litle or exterior evidence However internal damage can progress with additional mileage and eventually Cause internal tire separation detachment or sudden loss of inflation Impact damage may cause gradual inflation pressure loss After experiencing an unusual impact have the tire inspected by a tire service professional A rim bruise break pinch shock occurs when the tire strikes rigid object like a curb or pothole hard enough to crush the tire s sidewall between the rim fla
64. he most braking Road Surfaces Terrain Rapid or abnormal tread wear may be caused by abrasive road surfaces such as those with sharp oF coarse highway paving materials Areas that have numerous hills or curves can also lead to accelerated treadwear Axle Position The position of a tire on a vehicle determines what stresses the tire will experience The tires on the drive axle are affected by acceleration Depending the vehicle this can be the rear axle the front axle or in the case of four wheel drive both axles On front wheel drive vehicles the front axle also steers the vehicle and performs most of the braking Free rolling rear tires may also experience some abnormal tread wear Rotating tires on the vehicle may help to minimize abnormal wear Maintenance Conditions There is close relationship between several mechanical systems on a vehicle and its tires Tires wheels brakes shock absorbers drive train steering and suspension systems etc must all function together to perform safely and comfortably and to give optimum tread wear Improper or inadequate vehicle maintenance can cause tires to wear rapidly and or abnormally of the following maintenance conditions can be adjusted or repaired Improper Tire Inflation For optimum service use the inflation pressures specified by the vehicle manufacturer on the vehicle tire placard certification label or owner s manual Under inflation may result in r
65. imum load capacity than a SL tire of the same size however XL tires require higher inflation pressure to attain the added load capacity See Inflation Pressure above Tire Replacement Guidelines For XL tires an equal or greater load index is mot always an adequate indicator of a tires suitability for the load capacity As a result the maximum load capacity and inflation pressure which is also molded on the tire sidewall must be referenced Load Index The load index is the number preceding the speed symbol on a tire s sidewall For example if the tire is labeled as P215 65R15 95H then 95H is the service description where 95 is the load index For more detailed information see page 10 in Chapter 1 Tires with the same load index regardless of the tire size may carry the same load but not always and they may require different inflation pressures In addition some tire sizes are available in more than one load index The load index may not be used independently to determine replacement tire acceptibility for load capacity An equal or greater load index does not always correspond to equal greater capacity at all inflation pressure settings particularly when comparing P metric and Euro metric passenger tires Refer to the tire manufacturers recommended inflation pressures for the tire selected see Inflation Pressure OE vs Replacement Speed Rating Speed
66. in the accepted tolerance of the vehicle manufacturer Differences in overall diameter may affect vehicle handling and stability as well as the following speedometer odometer ABS tire pressure monitoring system 4WD AWD traction control and other electronic systems To maintain accuracy resetting or recalibration of these systems may necessary Compare the nominal dimensions on the vehicle placard and candidate replacement sizes Check the vehicle manufacturer s recommendations Plus g Plus sizing for light vehicles in the after market is primarily based on the following tire wheel Characteristics 1 Maintain overall tire diameter of the OE tires 2 Increase the tire section width contact patch footprint becomes shorter and wider 3 Decrease the series profile aspect ratio or section height 4 Increase the rim wheel diameter the appropriate ny standards organizations ching the Tre e ye Asolo E ry he manc For mone information approved rm refer to ire produc erature Er im vit Chapter 3 Page 43 Tire Replacement Guidelines Figure 12 Plus Size Concepts Hypothetical Examples Plus Concept Passenger Plus Concept SUV and Truck oMa O O Plus sizing is generally conveyed in terms of Plus 1 Plus 2 Plus 3 etc Examples of plus sizing are illustrated in Figure 12 If tire fitments
67. individual axle weights and total vehicle weights simultaneously when the vehicle is positioned properly These scales provide an easier method to determine individual position loads Single Axle Platform This scale weighs one axle at a time all tires on the same axle These scales provide an additional method to determine individual position loads Regardless of the method used the RV must remain as level as possible even if an axle or side is not physically on the scale There must be enough space the side of the scale to accommodate the RV being partially off the scale If there is a difference in the weights on one side of the vehicle compared to weights on the other side suspension components tires wheels brakes springs etc on the heavier side could be overloaded even if the total axle load is within the GAWR Redistributing the load is essential to avoid component failure as well as to improve the handling characteristics of the vehicle The actual or calculated weights can be compared with the GAWR GVWR and tire capacities The Chapter 4 Page 53 weights also help determine the proper inflation pressure for the tires HOW TO WEIGH A TRAVEL TRAILER 1 Weigh the travel trailer in its entirety while detached from the towing vehicle The overall weight must be less than oF equal to the GVWR for safe operation If the overall weight is greater than the GVWR contents must be removed until GVW
68. ire If two radial tires and two non radial tires are used on a vehicle put radials on the rear axle If radial and non radial tires are used on a vehicle equipped with dual rear tires the radial tires may be used on either axle Speed rated tire Ifthe vehicle tire placard and or owner s manual specifies speed rated tires the replacement tires must have the same or higher speed rating to maintain vehicle speed capability Tire speed ratings do not imply that vehicles can be safely driven at the maximum speed for which the tire is rated particularly under adverse road and weather conditions or if the vehicle has unusual characteristics Never operate a vehicle in an unsafe or unlawful manner Tire Replacement Guidelines If replacement tires have lower speed capability than specified by the vehicle manufacturer the vehicle s speed must be restricted to that of the replacement tire Also vehicle handling could be affected Consult vehicle manufacturer or tire manufacturer for recommendations Four wheel drive 4WD and all wheel drive AWD vehicles If no instructions for tire mixing appear in the vehicle owner s manual follow these guidelines DO NOT mix tire sizes All four tires must be marked with the same tire size unless otherwise specified by the vehicle manufacturer This also applies to winter snow ires DO NOT mix radial and non radial tires All four must be either radial or non radial DO NOT
69. ire failure even at a later date Do not exceed the maximum inflation pressure shown on tire sidewall Over inflated tires over the maximum molded on the tire sidewall are more likely to be cut punctured or damaged by sudden impact from hitting an obstacle such as a pothole maintain the correct pressure in RV tires check the inflation pressure regularly with dual head pressure gauge that is calibrated up to 120 psi in at least 2 psi increments Even if it is difficult to check the inflation pressures of inside tires in dual fitments it is imperative that these inflation pressures be checked and properly maintained because the inside dual tires are subjected to more severe operating conditions such as High heat exposure due to close proximity to brakes Lower air circulation to assist in cooling Crowned road surfaces which can cause inside dual tires to support more of the load than the outside dual tires Proper Inflation is Critical inflation pressure enables a tire to support the load and to control the vehicle therefore proper inflation is critical With the right amount of inflation pressure the vehicle and the tires will achieve their optimum performance In addition to tire safety this means your tires will wear longer and improve vehicle fuel consumption It is impossible to determine whether radial tires are properly inflated just by looking at them You must use a tire gauge to properly check
70. is like running the vehicle s engine without enough or coolant it may seem to work fine for a time but serious permanent damage has occurred Adding or coolant won t repair engine damage and adding inflation pressure won t fx damage The tire will remain seriously damaged and can still fall even after inflation pressure is corrected 1f a tire is losing inflation pressure a service professional should check the tire surface and the valve for the source of the leak s by using water soap solution prior to demounting the from the rim Mark the injured area and totaly deflate the tire Then remove the tire from the wheel being careful to avoid further damage to the tire particularly to the bead area Perform a complete internal inspection For vehicles equipped with dual tire assemblies duals if one of the dual tires becomes significantly lunderinlated or flat the other tire will carry the load for both tires resulting in an overloaded condition Both tires should be inspected by a service professional for damage See Tire Inspection Guidelines on p 16 Figure 6 Puncture Repair Area Puncture repairs are nid DO NOT make rats whae damage exends into the shoulder edge area OR where extends at an angle into shoulder area tere E any question that injury extends into hoo ge ae then tent be scrapped Always read understand
71. it would wear twice as well on the government course as a tire graded 300 The relative performance of tires depends upon the actual conditions of their use and may depart significantly from the norm due to variations in driving habits service practices and differences in road characteristics and climate Traction The traction grades from highest to lowest are AA A B and C and they represent the ability to stop on wet pavement as measured under controlled conditions specified government test surfaces of asphalt and concrete The traction grade assigned is based on braking 3 neler to Code of Federal Regulations 49 CFR 575 104 4 neler to Code of Federal Regulations 49 CFR 571 139 straight ahead traction tests and does not include comering tuming traction Temperature The temperature grades are A the highest B and C representing the tires resistance to the generation of heat and its ability to dissipate heat when tested under controlled conditions on a specified indoor laboratory test wheel The temperature grade is established for a tire that is properly inflated and not overloaded Excessive speed underinflation or overloading either separately or in combination can cause heat buildup which may result in tire damage and or tire failure UTQG Tire Marking Example TEMPE une Sidewall Marking for Retread Tires Applicable retread tires which operate on public roads in the United States
72. keep moisture out and Re inspect the finished repair Refer to the RMA wall charts for complete step by step procedures Tire changing can be dangerous and should be done by trained personnel using proper tools and procedures Always read and understand any manufacturer s warnings contained in owners manuals on the equipment listed on websites and molded onto tre sidewalls Failure to comply with these procedures may result in faulty positioning of the tire and or rim parts and cause the assembly to burst with explosive force sufficient ta cause serious physical injury or death Never mount or use damaged tires or rims For more information on tire mounting safety and procedures refer to the RMA wall charts Demounting and Mounting Procedures for Passenger and Light Truck LT Tires or Demounting and Mounting Procedures for Truck Bus Tires Ifa tire continually loses inflation pressure or has lost all or most of its inflation pressure it must be removed from the wheel for complete internal inspection to check for damage Driving on damaged tires is dangerous A damaged tire suddenly fail including by tread belt separation even ata later date which can lead to an accident and serious personal injury or death Never perform a tire repair without removing the tire from the wheel assembly for an internal inspection Do not perform an outside in tire repair or an on the wheel repair Th
73. lated and or over loaded Depending on nitrogen alone to reduce the requirements for inflation maintenance may lead to under inflated operation which may result in premature tire faure With the right amount of Inflation pressure the vehicle and tires will achieve Chapter 2 page 15 their optimum performance m addition to tire safety this means your tires will wear longer and improve vehicle fuel consumption Nitrogen and air can be mixed in any and al proportions Nitrogen filled tires can and should have air added whenever nitrogen is not readily available to maintain proper inflation as specified by the vehicle manufacturer For information on storing and handling nitrogen follow the manufacturer s and or supplier s safety guidelines Tire Loading To avoid over loading tires maintain the proper inflation pressure and never exceed the vehicle s load capacity gross axle weight ratings GAWR or the Gross Vehicle Weight Rating GVWR stated on the vehicle tie placard certification label or the vehicle owner s manual The vehicle load must also be distributed so that no individual axle tire or dual assembly is over loaded The maximum load for each tire is molded on the tire sidewall along with the maximum inflation pressure for that load Never exceed the maximum limits on the rim or wheel assembly For improved fuel efficiency reduce vehicle weight much as possible by removing unnecessary i
74. le has been parked for at least 3 hours or has been driven less than one mile at moderate speed The inflation pressure in tires including the spare and inside duals should be checked with an accurate tre gauge atleast once per month Additional checks should be made before long trips carrying heavy loads towing traller and any time high speeds anticipated This includes vehicles equipped with a Tire Pressure Monitoring System TPMS Maintaining proper inflation pressure maximizes fuel economy and optimizes overall tire performance Never bleed or reduce inflation pressure when tires are hot from driving as it s normal for pressures to increase above recommended cold pressures If a hot tire pressure reading is at or below recommended cold inflation pressure it may be dangerously under inflated In this case Immediately determine the cause and or have the tire checked by a tire service professional Passenger and light truck tires may lose 1 to 2 psi inflation pressure per month under normal conditions and 1 to 2 psi for every 10 degrees temperature drop if tire continually loses more than 2 psi per month have it checked by a tire service professional Significant changes in altitude or temperature at which a vehicle will regularly operate will result in changes in inflation pressure and wil require an inflation pressure check and adjustment Continuous inflation Pressure Loss
75. le and the vibration is still present next check the tire and rim for run a Place the suspect tire and wheel assembly the balance machine b Place a run out gauge or dial indicator in the center of the tread Set the gauge at c Slowly rotate the tire and rim assembly 360 degrees While rotating observe the gauge and determine the location of greatest run Mark that location on both the tire tread and wheel d Deflate the and rotate it until the mark the tire is exactly opposite from the mark the wheel 180 degrees e Reinfate the tire Recheck the tire wheel assembly run out by slowly rotating the assembly 360 degrees Ifthe run out has been reduced install the tire wheel assembly on the vehicle and perform a test drive If the run out has not been reduced find the peak run out If the peak run out is located near the area where the rim was originally marked the rim may be the cause Consult the rim manufacture If the peak run out is located near the area where the tire was marked the may be the cause of vibration Consult the tire manufacturer Chapter 2 rage 33 Zipper Ruptures in Steel Cord Radial Medium and ight Truck Tires following applies to tires with steel cord casings Any inflated tire suspected of having been operated under inflated and or over loaded must be approached with caution A tire service professional must remove the
76. le functions with the replacement runflat tires Emergency Temporary Single Conventional Tire Replacement Depending on the circumstances some runflat tires must be replaced after they have experienced low zero inflation pressure Never mix runflat tires with conventional tires tires that do not have runflat technology unless in an emergency situation on limited temporary basis The conventional tire should be replaced with a runflat tire as soon as possible It is nat recommended to mix incompatible runflat technologies products If a conventional tire is used on a temporary basis it is important to note that vehicle handling characteristics may be affected Also it is recommended that the conventional replacement tire is of the same size inflation pressure load carrying capacity and speed rating noted on the vehicle tire placard Runflat Replacement with Four Conventional Tires itis recommended and preferred to replace runflat tires with runflat tires however a consumer may wish to replace the OE runflat tires with non runflat conventional tires Consult with the vehicle and tire manufacturers before replacing runflat tires with conventional tires to identify any vehicle operation restrictions Ifthe conventional tire option is chosen then application restrictions apply including but not limited to the following Tire Replacement Guidelines Loss of runflat capability Emergency mobility is negated to m
77. lve Consult with the tire manufacturer for the meaning of match mount markings and recommendations for match mounting to wheels Match Mount Balancing Machines Consumer expectations and increased sensitivity of vehicles have resulted in additional procedures to produce smooth quiet ride Modern ride optimization machines may be used to resolve many ride vibration complaints These machines have the capability of evaluating the tire wheel assembly and the wheel alone following prescribed maich mounting procedures Match mounting techniques minimize Potential vibration Wheel measurements can highlight possible wheel irregularities Use of these machines can assist with diagnosis of tire wheel related vibration complaints However match mounting balancing machines are not laboratory or factory grade tire unformity measurement machines and should never be used to screen new tires for uniformity Consult the tire manufacturer for their policy regarding tires evaluated using match mount balancing machines Manual Ride Optimization Procedure Manual Run Out Method Follow these steps to manually diagnose tire wheel assembly suspected of causing vibration 1 Test drive the vehicle to determine where the vibration is originating 2 Place the suspect tire and wheel assembly on the balance machine and check its balance Correct if necessary and test drive the vehicle again 3 1f the balance is acceptab
78. mmable Substances Chapter 2 page 28 Tire Spinning Chapter 2 page 29 Mounting and Demounting Procedures Chapter 2 page 29 Tire Wheel Balancing and Installation Chapter 2 page 32 Zipper Ruptures in Steel Cord Radial Medium and Light Truck Tires Chapter 2 page 34 Tire Retreading Chapter 2 page 35 Chapter 3 Tire Replacement Gi Overview The Right Tire for the Vehicle Tire Size Inflation amp Load Self Supporting Runflat Tire Replacement Mixing Replacing Less Than Four TES n Rim Wheel Selection Vehicle Clearance and Tire Diameter Plus sizing Important Considerations Passenger and Light truck Used Tires Chapter 4 Recreational Vehicle Applications Overview RV Tire and Vehicle Placards Labels RV Tire and Vehicle Load Limits Proper RV Tire inflation Proper RV Tire and Vehicle Loading How to Determine an RV s Actual Weight RV Tire Inspection Cuidelines Severe Service Operation Sudden Ride Disturbance Vibration Rotation RV Service Life Proper Tire Repair Parking an RV Passenger and Light Truck Used Tires Storing RV Tires Chapter 3 page 37 Chapter 3 page 37 Chapter 3 page 37 Chapter 3 page 40 Chapter 3 page 41 Chapter 3 page 42 Chapter 3 page 42 Chapter 3 page 43 Chapter 3 page 43 Chapter 3 page 45 Chapter 3 page 46
79. mount of wear on each tire and extend the serviceability of the entire set Most RVs have a matching full size tire as its spare It is important that the full size spare is included in the RVs tire rotation See vehicle owners manual for rotation recommendations If tires exhibit uneven wear check for and correct if possible any misalignment imbalance or other mechanical problems before rotation When tires are rotated on an RV the inflation pressures may need to be adjusted for the tires new positions in accordance with the actual load on that wheel Position Under or over inflated tires may result in poor vehicle handling uneven treadwear increased fuel consumption and tire failure Note Lug nuts should be properly torqued anytime a tire rim whoel assembly is re installed on the vehicle RV Tire Service Life Tires used on RVs are typically subjected to a greater variety of service conditions often at or near maximum loads than automobile light truck and truck applications It is important to have the RV and its tires in good operating condition Even though RV users often put no more than a few thousand miles on their tires a year RV tires may need to be replaced because of service conditions long before the tread is worn out To determine if RV tires including the spare should remain in service it is recommended that they be periodically inspected by a tire service professional including an inspection before e
80. mpact break eg rim bruise break Bulges blisters or deep cuts cracks Excessive sidewall abrasion Exposed cords or fabric material Bead Conditions Sharply bent or broken beads or bead wites Deep cuts cracks Tom or severely chafed bead covers exposing fabric or wire Excessive rim flange grooving Innerliner Conditions Exposed body ply cords Unrepairable punctures Previous improper repairs Foreign object damage Cracking with visible cord material Run flat damage as exhibited by abrasions cracking blisters wrinkles discoloration breakdown of cord material Rim wheel and valves should be removed from service and replaced if any of the following are found Chapter 2 Page 17 Any rim wheel that is bent dented cracked excessively corroded or otherwise damaged Damaged valve and or valve core Common Types of Tire Damage Several types of tire damage are covered in this section However it is not all inclusive and should only be used as a general guideline for identifying a variety of damage conditions Refer to TIA s Passenger and Light Truck Tre Conditions Manual for additional information Under Inflation and or Over Loading Damage Under inflation and or over loading is the leading cause of tire failure so it is important to maintain inflation pressure and to properly load the vehicle See Proper Tire Inflation on p 13 and Tire Loading Under in
81. n makes it more likely for tires to be punctured or broken by sudden impact These situations can cause a tire failure including tread belt separation even at a later date which could lead to an accident and serious personal injury or death Consult the vehicle tire placard certification label or the owners manual for the recommended inflation pressures Proper Tire Inflation The recommended inflation pressures for tires are typically measured in pounds per square inch psi and are indicated on the vehicle tire placard certification label or in the owners manual Never set tire inflation pressures below the recommended inflation pressure found on the vehicle tie placard certification label or owner s manual Under Inflation causes excessive heat build up and intemal structural damage that may lead to a tire failure even at a later date Do not exceed the maximum inflation pressure shown on tire sidewall Over inflated tires over the maximum molded on the sidewall are more likely to be cut punctured or damaged by sudden impact from hitting an obstacle such as a pothole Example of a Vehicle Tire Placard 98 SEE 205 55 R6 9i Proper Inflation is Critical Inflation pressure enables a tire to support the load and to control the vehicle therefore proper inflation is critical With the right amount of inflation pressure the vehicle and the tires will achieve their optimum performa
82. nce In addition to tire safety this means your tires will wear longer and improve vehicle fuel consumption allowed in the tire irrespe Follow the vehicle man Chapter 2 Page 13 Note that some vehicles may have different cold inflation pressures for tites on the front and rear axles 1t is impossible to determine whether radial tires are properly inflated just by looking at them see Figure 3 You must use a tire gauge to properly check the inflation pressure Motorists should have their own gauge and keep it in the vehicle VE ned YOu cannot jast aking Properly Inflated Check inflation pressure with an accurate tre gauge A gauge calibrated in 1 psi increments up to 60 psi is sufficient for most passenger tires A dual head gauge calibrated in 2 psi increments up to 100 psi is Sufficient for light truck tres Even if it is difficult to check the inflation pressures of inside tires in dual fitments it is imperative that these inflation pressures be checked and properly maintained because the inside dual tires are subjected to more severe operating conditions such as 50 Under Inflated High heat exposure due to close proximity ta brakes Lower air circulation to assist in cooling Crowned road surfaces which can cause inside dual tires to support more of the load than the outside dual tires When to Check Inflation Pressure Check inflation pressure when tires are cold hat is when the vehic
83. nge and the rigid object Vehicles operated off Toad or in areas away from paved roads can encounter many objects that can cause tire damage Careful inspection of the tires should be made after use in off road service or ires that have been damaged by improper demounting mounting procedures may fail prematurely For instance tom bead may cause gradual inflation pressure loss and even lead to internal tire separation See RMA wall cham Demounting and Mounting Procedures for Passenger and Light Truck LT Tires Also see RMA Tire Information Safety Bulletin Vol 43 Avoid Tre Bead Damage on Tre Mounting Machines that Secure the Rim from Underneath Ozone Cracking or Weather Checking Weather checking ozone cracking can occur during direct and extended exposure to damaging effects of the environment such as ozone and heat from sunlight Ozone cracking can also be caused by exposure to electric motors welding equipment other ozone generating sources levels should not exceed 0 08 ppm parts per million Tires with severe weather checking ozone cracking any cracking extending to the casing cords plies should be removed from service For details on storing mounted and unmounted tires see Tre Storage Recommendations on p 26 Treating tires with incompatible dressings or harsh cleaning agents will hasten oxidation and result in premature cracking Always avoid petroleum based lire
84. o the vehicle tire placard and or certification label usually located on the vehicle door edge door post glove box or fuel door Also check the vehicle owner s manual for any additional tire replacement recommendations The vehicle tire placard identifies the size of the tires including the spare that were installed on the vehicle as original equipment The placard also specifies the recommended cold inflation pressures for the tires on the front rear axles and for the spare The placard may include seating capacity and combined weight of occupants and cargo Ifthe vehicle does not have a vehicle tire placard or certification label consult the vehicle Owners manual vehicle manufacturer or tire manufacturer A tire dealer should also be familiar with these requirements and is an excellent In addition tires have very useful information molded into the sidewall including the tire brand model size speed rating maximum load maximum inflation and safety warning s See Chapter 1 Tire Size Inflation and Load Tire Replacements Replacement tires should be the same as the OE size designation or approved options as recommended by the vehicle or tire manufacturer Never choose a replacement tire of a smaller tire size or with less load carrying capacity than the OE tire size at the specified vehicle placard pressure Under certain circumstances vehicle manufacturer may recommend or permit a specific s
85. o determine actual weights is to weigh the fully loaded RV wheel position by wheel position and axle by axle on level commercial scales Individual wheel position weights are the most critical for accurate load determination Certified public scales may be found at moving and storage lots farm suppliers with grain elevators gravel pits recycling companies and commercial truck stops Consult telephone book under scales weighing Allow adequate time since the entire process can lake up to 30 minutes There may be small fee for each weight taken but the expense is a worthwhile investment towards the safe and economical operation of the vehicle For the weighing of the RV to be meaningful it must be weighed fully loaded including passengers food clothing fuel water propane supplies etc Any towed vehicle car pickup boat or trailer or any item loaded on brackets on the back of the RV such as bicycles motorcycles storage units etc should also be included in the weighing PORTABLE WHEEL POSITION SCALES The most effective method of determining wheel position weights is to use portable scales designed for individual wheel position measurement Place a scale at each wheel position and record the load FIXED SCALES Platform long enough to weigh the complete vehicle Follow the steps on pages 55 to 57 for your particular vehicle to deterime individual position loads Segmented Platform provides
86. ommercially available lubricants made for bead seating to seat tire beads Also vegetable and animal soap solutions may be used Ifa lubricant is water based it should contain a rust inhibitor Care should be exercised to avoid excessive application of lubricant to minimize moisture in the pressure chamber Do not allow any lubricant to run between the tube and casing in tube type tires or on the inside surface of tubeless tires When dry the lubricant should not remain slippery Tire Mounting Aids and Bead Sealers Some mounting aids such as rubber O rings or donuts become trapped between the tire bead and rim during mounting This prevents the bead from properly seating on the rim which can lead to failure Bead sealers may also impede bead seating if allowed to dry on beads and rim contact surfaces before mounting Valve Maintenance Always remove and replace snap in valves when replacing tires Never reuse snap in valves Only valves that are compatible with the rim being serviced should be used Always cover the valve stem with a sealing cap This helps prevent moisture dirt and other contaminants Indes tin trc etn V al pe cg Uh ik To ddr Min up tn re ahe tin Chapter 2 Page 29 from entering the valve core as well as providing an additonal seal Any time a tire Is demounted for any reason including repairs inspect the valve stem for damage crack tears etc to determine if the valve stem
87. on pressure when seating beads Always use safety cage or other restraining device with clip on extension hose Only specially trained persons should mount ties Tire Wheel Balancing and Installation Tire wheel balance is important for proper tire tread wear Out o balance conditions may reduce tire mileage significantly and can be the source of vehicle vibration and bounce Maintaining tire wheel balance over the service of the tire helps to maximize the tire s performance There are two types of out of balance conditions for tire wheel assemblies that cause vibration at highway speeds See Figure 9 Static balance also known as single plane balance may result in vibration due to vertical up and down movement It can be corrected using a bubble or spin balancer Uneven distribution of weight across another axis of the wheel causes vibration due to rotational movement wobble or shimmy It can only be corrected using a dynamic spin balancer which also can correct static imbalance Dynamic Computer Controlled Balance Machine Set up and Usage Tire wheel service centers using dynamic spin balancing machines establish the optimal balance of the tite wheel assembly by correcting both types of imbalance Only trained tire service professionals should perform tire balancing Balancing equipment should be properly set up and calibrated with particular attention to the wheel assembly alignment eg
88. or service description See Tire Service Description on 10 for more information Merk tres do ot have an alpha character ref in size designation Chapter 1 Page 3 Passenger Tire Examples P Metric Womisms Gallon Win Diameter Cole Secon wan rose section wah Speed Symbol Wan aspecto Tonna Wao Spend Sibel With Cro econ Conamicton wan European Metric Metric Nominal Gear secion RG TT Ra WimD mercie Ladmdera seni Wath sehon Wath Symbol aspect ay sere Description T Type Temporary Spare Temporary Spare Nominal Gossaedion aloofness D Diagonal ar Rim Diameter Cale Wd wil fall Construction silices aspect rao NOTE Tre size designations without sence desrplons are no longer n general Chapter 1 page 4 Light Truck Tire Examples LT Metric T Tapa Umi aspect rasor TE Fara GE E TET ae 1 scan wah tes Conan Cae Speed symbol secion Wah pet rai Flotation Sra Ba Raa ar TTT Taal nes LT Numeric Tan oon TET GERE
89. oration business or firm Introduction The Rubber Manufacturers Association RMA represents companies that manufacture tres inthe United States The RMA and its members recognize how important tires are to safety ires are designed and manufactured with advanced technology and great care to provide thousands of miles of excellent service For maximum safety performance and service life they must be maintained properly This Care and Service Manual will address these and other factors relative tothe care and service of passenger car and light tuck tires For the most current printed materials visit RMA web site at rw rma org and click on Publications to search for other manuals bulletins wall charts etc For questions regarding RMA publications call 202 62 4900 and Light Truck LT Tires Including Tire Replacement Guidelines and Recreational Vehicle Applications CHAPTERS 1 Basle Tire Information 2 Tire Care and Service Tire Replacement Guidelines 4 Recreational Vehicle Applications published by Rubber Manufacturers Association 1400 K Street NW Suite 900 Washington DC 20005 Ai rights reserved The contents of us publication may not be reprinted or otherwise reproduced in any form without the express permission o RMA Rubber Manufacturers Association August 2011 Basic Tire Information CHAPTER 1 OF A 4 CHAPTER SERIES BASIC TIRE
90. other than the tire are desired always consult vehicle and tire manufacturers recommendations and consider the following Aspect Ratio Additional consideration should be made for substitute tires that are lower in aspect ratio than the OE tire fitments Lower aspect ratio tires typically aid performance and handling but they may provide a less comfortable ride High performance low aspect ratio tires may also wear more quickly and produce more noise during operation Low aspect ratio tires and their rim wheel assembly are more susceptible to damage from road hazards and pothole curb impact Overall Diameter Check to be sure that the overall diameter of all four tires is within the accepted tolerance of the vehicle manufacturer Inflation Pressure Check to see if it needs to be adjusted see Important considerations on p 45 Load Carrying Capacity Must be equal to or higher than the OE fitment Speed Symbol Category Must be equal to or higher than the OE fitment if the speed capability of the vehicle is to be maintained See Important Considerations on 45 Chapter 3 Page 44 Rim Wdh Ofrset Check O tim manufacturer s recommendations Rim Wheel Selection Never exceed the maximum pressure and or load capacity of the rim wheel Vehicle Clearances Steering tires must be checked in full left and right turns All wheel positions should be checked for proper clearance in
91. rating of the tire must be equal to or greater than what is specified by the vehicle tire placard or owners manual if the speed Capability of the vehicle is to be maintained For example ifthe tire is labeled as P215 65R15 95H then 95H is the service description where is the speed symbol If replacement tires have lower speed capability than specified by the vehicle manufacturer s recommendations the vehicle s speed must be restricted to that of the replacement tire Also vehicle handling could be affected Consult vehicle or tire manufacturers If the vehicle manufacturer s recommendations do not call for speed rated tires replacement tires may be speed rated if desired Chapter 3 Page 45 If installing winter snow tires and if the vehicle placard specifies speed rated tires winter snow tires of equivalent or greater speed rating must be fitted if the speed capability of the vehicle is to he maintained For cases where the winter snow tires speed rating cannot match the OE tire it is generally acceptable to apply a winter snow tire with a lower speed rating than the OE tire however the vehicle speed is to be restricted to that of the replacement tire Refer to the vehicle owner s manual for specific recommendations and or restrictions regarding winter snow tires Passenger and Light Truck Used Tires This information pertains to used passenger and light truck tires installed as repla
92. repairability and warranty End users of temporary tire mobility kits supplied as original equipment in a passenger car or a light truck vehicle should always follow all instructions provided by the vehicle manufacturer including limits on the amount of driving at reduced speeds allowed to safely reach tire service location 1 tire continually loses inflation pressure or has lost or most of its inflation pressure must be removed from the wheel for a complete internal inspection to check for damage Driving on damaged tires is dangerous A damaged tire can suddenly fail including by tread belt separation even ata later date which can lead to an accident and serious personal injury or death Never perform a tire repair without removing the tire from the wheel assembly for an intemal Inspection Do not perform an outside in tire repair or an on the wheel repair photo above is an example of a tre that was operated in an underinfated condition with a puncturing object that caused dangerous non repairable damage to the innerliner and body ply material This type of damage would not have been visible from the outside of the tire Every tire must be removed from the wheel for an inspection and to assess repairability Aftermarket Sealants The RMA does not endorse aftermarket sealant products Aerosol liquid gel or other substances injected into a through the valve are not considere
93. s generaly depleted above DO NOT make repairs where the injury damage extends into the shoulder belt edge area OR where the injury extends at an angle into the shoulder area there any question that the injury extends Into the shoulder bet edge area then the must be scrapped Not all tires can be repaired In addition to the RMA puncture repair procedures there may be additional limitations based on individual tire manufacturer repair policies These may include the type of service such as speed rating load index run flat technology Improperly repaired tires can fail while in service such as by tread belt separation which can lead to an accident and serious personal injury or death Tires must always be properly repaired described in the RMA wall charts Puncture Repair Procedures for Passenger and Light Truck Tires or Puncture Repair Procedures for Truck Bus Tires Load Range and Above Chapter 4 Page 59 and commercial application When repairing a tire puncture Never perform a tire repair on the wheel Never use only a plug stem Never use only a patch The basic principles for proper puncture repair Remove the tire from the wheel for inspection and repair Prepare the injured area Fill the injury with a suitable vulcanizing material or rubber stem that must fill the injury and keep moisture seal the innerliner with a patch to prevent loss of inflation and
94. sed as single Sidewall markings are given in both metric and English unis Follow tire inflation pressure recommendations on the vehicle tire placard certification label or in the owner s manual MAX LOAD DUAL 1260 kg 2778 Ibs AT 550 kPa 80 psi MAX PRESSURE COLD indicates the maximum load of the tire and corresponding maximum cold inflation pressure for that load when used in a dual configuration Sidewall markings are given in both metric and English units Follow tire inflation pressure recommendations on the vehicle tire placard certification label or in the owners manual RMA Show Tre Delos for Passenger and ht Fuck ies 3 Refer to RMA Tre formation Service Bulletin Vol 37 RMA Deon or Passenger and Light rk Tres f r Use Severe Snow Chapter 1 page 7 FIGURE 1 Passenger Tire Example qms 16 S Chapter Page FIGURE 2 Light Truck Tire Example Radial Construction Load Index faite hang to wm Nominal width of the tire in milimoters Light truck tire and eral asad Maximum load carrying are artem Chapter 1 rage not imply that a vehicle can be safely driven at the maximum speed for which the tire is rated particularly under adverse road and weather conditions or if the vehicle has unusual characteristics Consult the tire manufacturer for speed capability when there is no service description
95. ss Vehicle Weight Rating GVWR stated on the bel The vehicle Dad must also be rib so that no individual ade tire or dual overloaded The maximum load for each tire is molded on the tire sidewall along with the maximum inflation pressure for that load Never exceed the stated maximum limits on the tire rim or wheel assembly The major components of an RV the vehicle frame brakes axles rims wheels tires etc are designed to accommodate a particular weight If these weight ratings are exceeded these parts may wear rapidly or may fail prematurely in service The RV manufacturer provides the weight ratings and load specifications printed on the vehicle tire placard certification label as follows GVWR Gross Vehicle Weight Rating weight rating established by the chassis manufacturer as the maximum weight including vehicle cargo liquids passengers etc the components of the chassis are designed to support GAWR Gross Axle Weight Rating for each The maximum weight rating that the components tires rims wheels brakes springs and axle of each axle are designed to support This is determined by the lowest design capacity of any component In other words ifthe wheels have the lowest design capacity of any component on that axle installing tires with a higher load capacity does not increase the GAWR By regulation the tire load rating times the number of tires on that a
96. storage area s floor Surface to minimize exposure to moisture or damage Avoid contact with petroleum based products and or other volatile solvents or substances Store tires away from electric motors battery chargers generators welding equipment or other ozone generating sources Indoor storage is recommended however if tires must be stored outdoors Store tires where they are raised off the ground or on storage racks and not in contact with heat absorbent surfaces Protect tires with an opaque waterproof covering with some type of vent openings to avoid creating a heat box or steam bath effect 22 to RMA Tee eration Service Bulletin Vl 46 Passenger and Light Duck Ts 23 Refer to RMA formation Service Bulletin Vel 23 Somge Reonerendaons Chapter 4 Page 61 There is a danger of serious injury or death if a tire of one bead diameter is installed on rim or wheel of a different rim diameter Always replace a tire with another tire of exactly the same bead diameter as the diameter of the rim on which it will be mounted For example 16 goes on a 16 rim Never mount a 16 tire on a 16 5 rim A 16 5 tire goes on a 16 5 rim Never mount a 16 5 tire on a 16 rim While itis possible to pass a 16 diameter tire over the lip or flange of a 16 5 size diameter rim it cannot be inflated enough to position itself against the rim flange If an attempt is made to s
97. such as Lack of warning of low inflation pressure until one more tres are as much as 25 below the vehicle manufacturer recommendations May only detect inflation pressure differences between tires other words if al tires are losing inflation pressure at the same rate itis possible that the TPMS will not adequately warn of inflation pressure loss May not war of rapid inflation pressure loss in a single tire Under inflation prior to a TPMS warning is increasingly dangerous at high speeds heavy vehicle loads extended distances and at high ambient temperatures Spare Tire Inflation Pressure Full size and temporary spare tire inflation pressure should be checked monthly and before any long trips Use an accurate gauge T type temporary spare tires require 60 psi 420 kPa When adjusting inflation pressure in T type tires do so in small amounts since the tire is smaller and the pressure level changes rapidly mot over inflate Valve Caps Always cover the valve stem with a sealing cap This helps prevent moisture ditt and other contaminants from entering the valve core as well as providing an additional seal Inflation Pressure for Off Road Use Inflation pressures for tires used in most offroad situations should be the same as those for highway driving If a lower inflation pressure is used to gain additional at low speeds the tires must be re inflated before resuming driving on the highw
98. sure Speed rating such as S T U Hy z etc must be equal to or greater than what is specified by the vehicle manufacturer if the speed capability ofthe vehicle is to be maintained Also see Tire Mixing on p 4l and Important Considerations on p 45 Tire Replacement Guidelines Tire Size Designation Differences Between Passenger and Light Truck Tires Passenger Tires P Metric European Metric Light Truck Tires LT Metric LT High Flotation European Commercial Metric and LT Numeric These groups of tires have differences in their load and inflation characteristics including some differences in their load capacity if they are applied to a passenger car versus a light truck Vehicle handling may be affected when passenger tires are replaced with LT tires Therefore it is necessary to carefully consider these differences when considering a replacement tire that is not the same as the OE size Light Truck Tire Replacement In addition to the considerations already stated also sure to take into account the following items relative to light truck LT tire replacement Tires should only be mounted on approved rim widths see Tire Rim Wheel Selection on p 42 If changing tire size the rim wheel must have adequate load and inflation pressure capability For rims wheels not so identified or for service conditions exceeding the rated capacities consult the rim wheel manufacturer
99. t are in poor condition Rocks holes or other objects can damage tires and cause wheel misalignment When driving on such surfaces drive carefully and slowly Before driving on paved roads at highway speeds examine the tires for any damage such as cuts or penetrations 20 Refer to Code of Federal Regulations 49 CFR 570 62 and 49 CFR 39378 Chapter 4 Page 54 Weighing an RV or Travel Trailer Depending on the type of vehicle use the Illustrations on p 55 56 or 57 to assist in weighing For additional assistance information consult with an RV or tire service professional The vehicle weight at each particular wheel position must not exceed the maximum tire load capacity Over loading the tire wheel assembly lead to tire or wheel failure which may result in an accident serious personal injury or death Weighing a Single Axle Recreational Vehicle RV To Obtain Axle and Gross Vehicle Weights STEP ta STEP th STEP te STEP 1a sya ol Scale Weight Is be be be anon Cm From Owners de ba Manual Gun m RV To Obtain Individual Wheel Position Weights STEP 2a STEP 2 STEP 20 One Sido be gt be Seale Weight suas E Calculate Other be e Side West ros pe Tire Load bs bs EI ination psi ET Not 1 Hom he
100. t is also possible to be within the overall vehicle s weight rating Gross Vehicle Weight Rating or GVWR yet still have over loaded axle ends or tires That occurs because the load is not distributed evenly Proper weight distribution may be difficult to determine when loading a vehicle The vehicle load can be unevenly distributed from front to rear or side to side Uneven loading may cause the load to be within an axle or tire s load carrying capacity on end of an axle and over capacity on the other Some types of load leveling systems compensate for uneven weight distribution making it more difficult to notice Properly weighing the vehicle is the only way to be sure The most critical point about weighing a vehicle is that it must be weighed fully loaded including everything that will be on board while traveling That means the vehicle must be weighed with passengers supplies food water fuel oil towed items bicycles clothing propane etc Note that water fuel and propane can easily exceed 750 Ibs The Gross Axle Weight Rating GAWR or the Gross Vehicle Weight Rating GVWR must never be exceeded If any tires maximum load capacity is not adequate to support the actual weight on that tire position there are two chaices 1 Lighten the load 2 Install tires with a higher load carrying capacity If it is decided to install a tire size other than that originally provided on the vehicle care must be
101. taken to ensure adequate load carrying capacity and compatibility between the tire and rim Always supply a detailed weight slip for the vehicle listing individual wheel position load information to a tire service professional before proceeding This is the only way a tire service professional can determine which tire size has adequate load capacity and is capable of proper inflation pressure If the vehicle has dual rear tires installing a tire size other than the original size will require proper matching and spacing of the dual tire assembly If chains are used Under inflation and or aver loading of a tire causes excessive heat build up and internal structural damage This may cause a tire failure including tread belt separtion even at a later date which can lead to an accident and serious personal injury or death Over loading an RV can have other serious safety consequences such as suspension or wheel failure increased braking distance or brake failure particularly on steep grades and adverse vehicle handling stability Consult the vehicle tire placard certification label and owner s manual for the recommended vehicle load limits and tire inflation pressures Chapter 4 Page 52 particular care must be taken to assure adequate Clearance between loaded tires to avoid damage from chains Consult a tire service professional for proper application How to Determine an RV s Actual Weight The only sure way t
102. tems from your cargo storage areas in addition to keeping tires properly inflated Consul your vehide owners manual for load recommendations and special instructions such as trailer towing Sudden Ride Disturbance or Vibration If the vehicle experiences a sudden vibration or ride disturbance and or there is a possibility the tires and or vehicle have been damaged gradually reduce speed Do not abruptly brake or tum Drive with caution until you can safely pull off the road Stop and inspect the tire If the is under inflated damaged deflate and replace it with the spare If a cause cannot be detected the vehicle should be towed to the nearest vehicle or tire dealer for an inspection Under inflation and or over loading of a tire causes excessive heat build up and internal structural damage This may cause a tire failure including tread belt separation even at a later date which can lead to an accident and serious personal injury or death Over loading a vehicle can have other serious safety consequences such as suspension or wheel failure increased braking distance or brake failure particularly on steep grades and adverse vehicle handling stability Consult the vehicle tire placard certification label and owners manual for the recommended vehicle load limits and tire inflation pressures Tire Inspection Guidelines addition to maintaining inflation regularly Inspect the tire tread and si
103. ter rim it CANNOT be inflated enough to position itself against the rim flange If an attempt is made to seat the tire bead by inflating the tire will break with explosive force and could cause serious injury or death Rims of different diameters and tapers CANNOT be interchanged The following diagram illustrates the difference between rims of two different tapers and diameters The following diagram shows how beads of a 16 tire will not seat on a 16 5 rim The beads CANNOT be forced out against the rim flanges by using more air pressure because this will break the beads and the tire will explode with force sufficient to cause serious injury or death Chapter 3 Page 39 Self Supporting Runflat Tire Replacement Runflat tires have specific servicing requirements such as product specific puncture repair or demounting mounting procedures which vary by vehicle and tire manufacturers Consult with the manufacturers for details A functioning tire pressure monitoring system TPMS must be used with runflat tires Four Tire Runflat Replacement When replacing tires normally Le wear out it is recommended and preferred that all four runflat tires are replaced at the same time with four runflat tires in order to maintain runflat tires mobility TPMS capability and vehicle handling stability and performance Check owners manual for specific recommendations It is important to ensure that the TPMS on the vehic
104. to determine the rim wheel capabilities Body and chassis clearance must be checked on the vehicle s front and rear axles see Tire Vehicle Clearance and Tire Diameter on p 43 Proper spacing between duals minimum dual spacing is necessary for optimum tire performance Consult tire or vehicle manufacturers literature for recommendations If chains are used particular care must be taken to assure adequate clearance between loaded tires to avoid damage from chains Allowable outside diameter differences between a tire and its dual mate is 1 4 for light truck tires For tube type tires be sure to use approved tubes flaps valves for the replacement tire When used in radial tires radial tubes and radial flaps are required Chapter 3 Page 38 Replacing OE Passenger Tires with LT Tires Some vehicles such as sport utility vehicles vans and pick up trucks may have passenger tires installed as original equipment As previously stated it is preferred that replacement tires should be the same OE size designation or approved options as recommended by the vehicle or tire manufacturer However in some cases the OE passenger tires on these types of vehicles can be replaced with light truck tires which are tires marked with an LT designation on the sidewall LT tires for light vehicles which are vehicles with Gross Vehicle Weight Rating GVWR of 10 000 Ibs or less include load ranges 1 and
105. ubstitute tire size inflation pressure maximum speed maximum load elc It is recommended that all four tires be of the same size speed rating and construction radial non radial In some cases the vehicle manufacturer may specifically advise against the application of replacement tires that are not the original size In other cases the vehicle manufacturer may require different sized tires for either the front or rear axles Also see Tire Mixing on p 41 and Important As den by 49 CHE Part 571 139 Federal Mar Velde Sft Standard VSS 1391 Rh vies re moto veldes with a goss vlde weight rating GVWR a 10060 Be or es Tr sizes frig veces cde sl passenger car res and Beh track sizes ough Load Range E Chapter 3 Page 37 Considerations on p 45 Always check and follow the recommendations in the vehicle owners manual Replacement tires must have Inflation pressure capability equal to or greater than the operating inflation pressure specified the vehicle tire placard When determining the proper tire inflation pressure settings for substitute tires never exceed the maximum pressure listed on the sidewall ofthe tires Carefully note any differences between recommendations for front and rear axle positions regarding the tire size and or inflation pressure Load cartying capacity must be equal to or greater than the load carrying capacity of the OE lire size at the specified vehicle placard pres
106. uld not be used with any other rims wheels mor should standard tires snow tires wheel covers or trim rings be used with the high pressure type temporary spare rim wheel A T type temporary spare tire and wheel assembly should never be used on a vehicle with which it is not compatible nor should more than one such tire ever be placed on any vehicle at a given time Standard tires or snow tires should NOT be mounted a high pressure compact spare wheel Mismatch of the tire and or rim parts may cause the assembly to burst with explosive force sufficient to cause serious physical injury death 16 means approved ire and and approved im assole European he nd Rim Organisation Tire Replacement Guidelines Tire Vehicle Clearance and Tire Diameter Acceptable load index load capacity and or overall diameter do not imply acceptable vehicle clearance Body and chassis clearance must be checked on the vehicle s front and rear axles If replacement tires rims are of a different size from the original equipment all four 4 wheel positions must be checked for proper clearance in the fender well around brake components shock towers other suspension components etc These wheel positions must be checked for full suspension jounce and rebound Steering tires must be checked in full lett and right tums Also check to be sure that the outside circumference of all four tires is with
107. unlight high heat ozone and other potentially damaging conditions Store where the area is clean dry and well ventilated but with a minimum of circulating Store tires an area with temperate ambient conditions mild temperatures shaded or dark Store raised off a storage area s floor surface minimize exposure to moisture or damage Avoid contact with petroleum based products and or other volatile solvents or substances Store tires away from electric motors battery changers generators welding equipment or other ozone generating sources tro ee rain Serie let Vl Pee and Mk Ud s Thee to RMA Toe Sri iei vel 2 e Sage Remedios Chapter 2 page 26 Indoor storage is recommended however if tires must be stored outdoors Store tires where they ate raised off the ground or storage racks and not in contact with heat absorbent surfaces Protect tres with an opaque waterproof covering with some type of vent openings to avoid creating a heat or steam bath effect If ties are mounted on a stored vehicle Store the vehicle such that all weight is removed from the tires If vehicle weight cannot be removed unload the vehicle to minimize the weight Maintain the recommended tire inflation pressure including the spare The surface where parked stored should be firm reasonably level drained and clean Vehicle should be moved every
108. valve core and completely deflate the tire before removing the tire wheel rim assembly from the vehicle Clearly mark the tire in an appropriate manner indicating it has been run under inflated and is a potential for a zipper rupture Do not retum the tire to service without following proper procedures including an inspection by a tire service professional See RMA Tire Information Safety Bulletin Vol 33 Inspection Procedures to Identify Potential Sidewall Zipper Ruptures in steel Cord Radial Truck Bus and Light Truck Tires A grazing light or other indirect light Source used during inspection reveal rupture Note the characteristic ripper lie seam along the sidewall where the rupture occured Any steel cord radial tire suspected of operating under inflated and or over loaded must be approached with caution Permanent damage due to operating tire under inflated and or over loaded cannot always be detected Any tire known or suspected of being operated at 80 percent or less of normal operating inflation Pressure and or over loaded could possibly have permanent sidewall structural damage steel cord fatigue Ply cords weakened by under inflation and or over loading may break one after another until a rupture occurs in the upper sidewall with accompanying instantaneous pressure loss and explosive force This can result in serious injury or death See RMA Tire Information Safety Bulletin Vol
109. very travel season and during routine RV maintenance intervals like oil changes and tire rotations The service life of tires includes their overall condition and vehicle usage factors not just tread wear All of these factors should be taken Into account when considering tire replacement See RV Tire Inspection Guidelines on page 54 Driving on damaged tires is dangerous A damaged tire can suddenly fail leading to situations that may result in serious personal injury or death Tires should be regularly inspected by a qualified tire service professional Follow vehicle and tire manufacturers specific recommendations if any regarding tire service life and replacement In order to determine the age of the tire look for the last four digits of the DOT tire identification number see Chapter 1 Basic Tire Information for details For example a tire with a DOT tire identification number ending with the last 4 digits of 0309 indicates it was manufactured the 3rd week of 2009 RV tires that have been permanently removed from service should be rendered unserviceable and destroyed so no one else can use them Tire Service Life is Not Determined by Chronological Age Tires are composed of various materials including rubber having performance properties essential to the proper functioning of the tire These component properties evolve aver a combination of time service and storage conditions For each individual tire this
110. will break with explosive force and could cause serious injury or death Rims of different diameters and tapers cannot be interchanged The following diagram illustrates the difference between rims of two different tapers and diameters CERT En i The following diagram shows how beads ofa 16 wil not seat on a 165 rim The beads cannot be forced against the rim flanges by using more inflation pressure because this will break the beads and the tire will explode with force sufficient to cause serious injury or death Never under any circumstance introduce a flammable substance into a tire Igniting this substance in an effort to facilitate seating the beads is extremely unsafe This may result In an explosion of the with force sufficient to cause serious personal injury death This practice may also result in undetected damage to the tire or rim that could result in failure of the tire in service Silicone petroleum or solvent based lubricants must not be used These substances may cause the tire to slip on the rim have harmful effect on the tire tube flap and or rim create explosive mixtures of air and vapors in the tire Which may result in serious injury or death Chapter 2 rage 31 Serious injury or death may result from explosion of tire and rim wheel assembly due to improper mounting Never exceed 40 psi inflati
111. xle must equal or exceed the GAWR for that axle GCWR Gross Combined Weight Rating GCWR represents the maximum allowable total loaded weight rating of the vehicle and vehicle trailer it is towing GCWR minus GVWR represents the allowable weight for the towed vehicle GVW Gross Vehicle GVW is the actual weight of a fully loaded vehicle including vehicle cargo liquids fuels passengers tongue weight etc The GVW must not exceed the GVWR GAW Gross Axle Weight GAW Gross Axle Weight GAW is the actual weight of a fully loaded vehicle carried by a single axle Due to the many ways that weight can be distributed within an RV GAW can often provide a false sense of security The total weight on an axle may be within the axle s rating but the distribution of the load may be overloaded on one side The GAW must not exceed the GAWR 19 Tongue weigh the down weight exerted st h ach or Rh whee connection by a ily lone owe ndr The owing vehicles ea the towed zs tes prt tas weigh Chapter 4 Page 49 Proper RV Tire Inflation The recommended inflation pressures for RV tires are indicated on the vehicle tire placard certification label or in the owner s manual Never set tire inflation pressures below the recommended inflation pressure found on the vehicle tire placard certification label owners manual Under inflation causes excessive heat build up and internal structural damage that may lead to a t

Care and Service of Passenger and Light Truck

Contents

Download Pdf Manuals

Related Search

Related Contents