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Clutch Problems, Troubleshooting, and Service - Goodheart

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1. A A only B B only C Both A and B D Neither A nor B A flywheel has deep scoring and cracks Technician A says that any amount of metal can be cut from the flywheel to fix this condition Technician B says that the flywheel can be lightly sanded and reused Who is right A A only B B only C Both A and B D Neither A nor B Technician A says that a clutch disc should be reused unless wear or damage is severe Technician B says that all replacement clutch parts should be carefully compared to the old parts to help ensure they will work properly Who is right A A only B B only C Both A and B D Neither A nor B Technician A says that a pressure plate must apply evenly to prevent clutch grabbing Technician B says that the throwout bearing should be replaced if it shows any signs of wear or damage Who is right A A only B B only Both A and B C D Neither A nor B 156 17 18 A car has a slipping clutch The car will still move but the engine races when accelerating Technician A says to pull the transmission and replace the clutch Technician B says to adjust the clutch linkage first Who is right A A only B C D A car shudders when accelerating from a standstill as the clutch pedal is released Technician A says to check for loose softened or broken motor mounts Technician B says to check the clutch and flywheel friction surfaces fo
2. The actual noise is caused not by the clutch but by the vibration set up in the clutch linkage and drive train Chatter can be caused by loose or misaligned drive train components For example the transmission and clutch housing may be seriously misaligned Often what seems like clutch chatter is really a worn out constant velocity joint or other universal joint Other causes of chatter include a misaligned flywheel a worn pilot bearing or both It is possible that release levers are unevenly adjusted or worn Sometimes dust from a worn clutch disc facing clogs the disc segments and cause chatter 130 Clutch Vibration Some clutch defects can result in a vibration that can be felt inside of the vehicle while the clutch is fully engaged This clutch vibration varies with engine speed It differs from chatter which occurs when the clutch is in the process of being engaged or disengaged Often clutch vibration is accompanied by noise however the noise is a secondary symptom Several checks must be made to find the source of the vibration This is to determine if the problem is clutch vibration or vibration from another source Vibration with the vehicle moving may be caused by the engine or any part of the drive train To narrow down the possibilities determine when the problem occurs If the vibration occurs only when the vehicle is moving the prob lem is probably not clutch related Even so you should check the bolts that sec
3. This preferred method is outlined as follows 1 Fill the system reservoir with fresh brake fluid Leave the cover off the reservoir Bleeder valve is closed 2 If the bleeder valve has a cap remove it at this time Attach a hose to the end of the bleeder valve Place the free end of the hose in a clear container Fill the container with enough fluid to cover the bottom of the hose 3 Have an assistant pump several times on the clutch pedal Then ask the assistant to hold the pedal down 4 Open the bleeder valve by loosening it about a quarter or half turn Make sure your assistant continues to keep his or her foot on the clutch pedal The pedal will probably go all the way to the floor Air or a mix ture of air and brake fluid will come out of the bleeder valve Keep the outlet of the hose submerged in the fluid as it begins to fill the container Watch for air bubbles 5 Close the bleeder valve once the flow stops 6 Let up on the clutch pedal 7 Repeat the process until only brake fluid comes out of the bleeder valve This can be noted by watching the air bubbles emerging from the hose as the system is bled 8 Top off the system reservoir with fresh brake fluid and put the cover back on the reservoir Do not reuse fluid bled from the system as it may be contaminated There is an alternative method of bleeding air from a hydraulic system It can be done without an assistant and without wasting brake fluid howeve
4. gear usually reverse If the gear engages smoothly the creeping is caused by spindown which is normal If the gear clashes the creeping is caused by clutch drag Consult Chapter 8 for an explanation on synchronizers Clutch drag can be caused by a clutch linkage that is loose disconnected or inoperable The clutch fork inside the clutch housing may be disconnected from the throwout bearing A hydraulic linkage may be low on fluid the reservoir may be empty or the cylinders or lines may be leaking There might be air in the system A discon nected linkage or clutch fork or a dry hydraulic system is characterized by a pedal that requires little if any effort to depress A spongy pedal is the result of air in a hydraulic linkage Another possible cause of clutch drag is misalignment of the transmission or clutch housing This can happen as a result of loose bolts or as a result of debris between the mounting faces Misalignment can cause the linkage or internal clutch parts to stick temporarily Pedal effort will be normal or higher than normal Clutch drag can also be caused by a worn or frozen pilot bearing a sticking or warped clutch disc or a warped pressure plate or flywheel A worn disc may become so overheated it welds itself to the pressure plate When these defects occur the clutch linkage is working properly but the engine and transmission remain mechanically connected One of the most common causes of a dragging clutc
5. the surface the disc is worn out and should be replaced Honda DaimlerChrysler Elongation of the bolt holes in the clutch cover is an indication the clutch cover attaching bolts were loose The pressure plate assembly may bounce against the flywheel if these bolts are loose which would cause the holes to elongate Check for weak pressure plate springs and for signs of overheated springs The release fingers or levers should be checked for wear and misadjustment If any fingers or levers are lower than the others the pressure plate application will be uneven The clutch may grab or chatter Severe wear at the contact point with the throwout bearing indicates the clutch has seen much use or there was no free play Figure 7 30 shows various types of pressure plate assem bly damage you might find during inspection along with possible reasons the damage occurred This damage may range from chatter marks on the pressure plate to a scored pressure plate or broken release levers Being able to readily identify the damage will result in better service times 146 Manual Drive Trains and Axles Chapter 7 Clutch Problems Troubleshooting and Service 147 nly Tat od ri i a ai a5 es a T an ee e om pions ee A Burned disc facing Oil contamination slipping clutch B Hub splines worn Improper engine to transmission align A Chatter marks on pressure plate Oil or grease contamination B Broken pressure plate retracting
6. assembly is out of balance The parts that are heavy enough to be seri ously unbalanced are the flywheel and pressure plate A balance problem is often found after new parts are installed or the flywheel is resurfaced The chance of a flywheel or pressure plate becoming seriously unbalanced after long use is slight UO A part associated with the clutch assembly is loose or broken Check attaching bolts of the clutch assembly The flywheel attaching bolts flywheel to crankshaft bolts may be loose on the crankshaft or there may be dirt or metal burrs between the crankshaft flange and flywheel This causes misalignment of the flywheel When this happens the clutch usually has other symp toms The clutch may slip or make a knocking noise Manual Drive Trains and Axles Clutch housing Loose bolts are often a to engine source of vibration and noise Clutch cover A Transmission to x lt clutch housing to flywheel p Bearing Flywheel Ba retainer to ee on transmission P T gt Clutch fork ball Figure 7 3 Note places where bolts can loosen causing vibration and noise Often bolts can be tightened to solve the problem Occasionally the vibration will damage other parts before the bolts are tightened Clutch Explosion A clutch explosion occurs when clutch components fly apart due to centrifugal force Major causes of clutch explo sions are excessive clutch rpm severely unbalanced compo nents and l
7. attaching bolts connecting the transmission to the clutch or engine are removed This can cause damage to the clutch disc splines or transmission input shaft Make sure for this and for other reasons you support the transmis sion at all times If a transmission were to fall it could cause injury or damage Be especially careful when lowering a transmission and transfer case combination as the weight of the transfer case is usually off center 6 Remove as much dust as possible from inside the bellhousing with an approved vacuum collection system designed for use with asbestos fibers in particular Manual Drive Trains and Axles Transmission jack Figure 7 17 Transmissions are heavy Use a transmission jack to support and lower the transmission from the vehicle Owatonna Tool Warning Some clutch discs contain A asbestos a powerful cancer causing sub stance Avoid breathing dust from inside the bellhousing or clutch assembly Do not blow dust off these components with compressed air 7 Remove the throwout bearing from the clutch fork If the clutch fork pivots on a ball stud remove the fork at this time Most clutch forks are held to the ball stud by spring clips See Figure 7 18 In many cases the clutch fork can be removed by pushing or pulling the inner end toward the front of the housing while pulling the other end straight out 8 If still in place remove clutch housing from the back of the engine I
8. cylinder bore The piston should slide out of the cylin der In some cases the piston will pop out of the cylinder because of a return spring behind it If the pis ton is stuck it can be removed by tapping the cylinder on a wooden block or by carefully applying air pres sure to the inlet connection to fly out with great force Point the open end of the cylinder away from yourself and others and toward rags or some other soft surface before applying pressure Warning Air pressure can cause the piston Reservoir cap Master cylinder Reservoir Pushrod Snap ring Retaining Dust boot washer clamp Piston rear seal A Piston front oy P Stem tip seal Spring Valve retainer stem Valve stem Return Retainer A Piston retainer spring spring valve cap Bleeder Bleeder A valve Spring Pushrod p SS Seal Piston Snap ring Dust cover B boot Figure 7 14 Study the exploded views of master and slave cylinders A A master cylinder is shown The shape the included parts and their layout can vary The manufacturer s service manual should be consulted for an exact breakdown of parts B A slave cylinder is shown It too can vary as to parts shape and layout DaimlerChrysler General Motors 3 Once the piston is out inspect the cylinder for wear or pitting If the cylinder bore is worn or pitted the cylinder must be replaced Remove the old seals from the piston and disc
9. flywheel and the crankshaft flange The spacer should be saved for reassembly After removing the flywheel check the rear main bearing seal for leaks If the seal is leaking oil could reach the new clutch disc and ruin it just as it may have ruined the old disc A leaking seal must be replaced 143 Flywheel repair Some flywheels may be damaged beyond repair Others may be repaired and then reinstalled Some of these may be fixed by replacing the ring gear or by resurfacing Flywheels with damaged ring gears are usually replaced Some ring gears can be removed from the fly wheel and replaced Figure 7 26 Flywheel Use chisel to split and remove ring gear To PNG Heat new ring gear to expand and ease installation Figure 7 26 Most manual transmission flywheels have a removable ring gear A A chisel is being used to remove the ring gear from a flywheel Be careful not to damage the flywheel B You should heat the replacement ring gear with a torch or in an oven Be careful not to overheat the ring gear or the metal will lose its strength C Place the new ring gear over the flywheel and ensure that it is properly seated Always wear gloves or use tongs to prevent burning your hands when handling the hot ring gear General Motors 44 Some flywheel ring gears are welded into position others are a shrink fit If it is determined that the ring gear is to be replaced it can be cut from the flyw
10. for roughness and lack of grease Always replace a throwout bearing that shows any sign of defects The throwout bearing can be pressed from its collar and a new bearing can be installed The clutch fork should be checked for wear Worn forks should be replaced Clutch housings do not wear out but they should be checked for cracks and warping The housing may contain a ball stud for the clutch fork The stud should be checked for wear and replaced if necessary When reassembling the clutch always make sure your hands are free from oil Oil or grease on the clutch disc will cause grabbing or slippage A pilot shaft should be used to ensure the disc hub splines and pilot hole line up closely If proper alignment is not obtained the transmission will be difficult to install The clutch cover attaching bolts should always be tightened with the pilot shaft in place After the clutch and other drive train parts are reinstalled the clutch pedal free play should be adjusted to specifications Road test the vehicle as the final step Review Questions Chapter 7 Please do not write in this text Place your answers on a separate sheet of paper 1 Explain what the phrase riding the clutch means What effect can it have on the clutch over time 2 Which of the following items concerning the phrase dumping the clutch is not true A Pressure plate apply springs engage gradually B Means increasing engine speed and then suddenly releasing th
11. new springs are used install them using the sequence shown otherwise return the springs to their original positions Gauge plate Spare flywheel G To ensure uniform clutch application the release levers must be set to equal heights Place the gauge plate on the spare flywheel and place the pressure plate assembly over it The gauge plate occupies the position normally occupied by the clutch disc and simulates installed component positions Bolt the clutch cover to the flywheel Note that spacers or shims may be used instead of gauge plate Figure 7 31 Continued collar is worn the fork usually is worn also Any worn parts should be replaced Figure 7 32 shows damage related to the throwout bearing which you might find during inspection along with possible reasons the damage occurred Throwout bearing assembly repair Some throwout bearings are an integral part of the bearing collar These are replaced as a unit Many throwout bearings however are a press fit onto the bear ing collar The assembly can be repaired by replacing the bearing or collar whichever is in need of repair 149 Cover Springs and levers in position EFE New or resurfaced pressure plate F With the pressure plate assembly positioned on the arbor press as per original setup slowly apply pressure to the clutch cover The drive lug openings in the clutch cover should fit over the drive lugs apply springs should fit into
12. seal Transmission a input shaft damage or wear Clutch housing misalignment or damaged Figure 7 1 Note typical problems with the clutch assembly Some defective parts such as a leaking engine oil seal are not part of the clutch assembly but can cause clutch problems It is very unusual for only one part of a clutch to wear out You should usually replace any clutch part that you suspect is bad DaimlerChrysler Chapter 7 Clutch Problems Troubleshooting and Service you the technician to find out what caused the prema ture clutch damage so the problem might be prevented in the future As stated clutch problems can occur as a result of careless operation Driving with a foot resting on the clutch pedal is an example This careless habit called riding the clutch causes the clutch to slip As a result excess heat is generated and premature wearing of clutch friction surfaces occurs Among the different ways clutches are misused riding the clutch is the most common It can put the equivalent of 50 000 miles of normal wear on a clutch in under 10 000 miles Naturally clutch problems can occur as a result of abuse An example is increasing engine speed and then suddenly releasing the clutch pedal allowing the pressure plate apply springs to engage the clutch almost instantly This is often referred to as dumping the clutch or popping the clutch It causes instant heat buildup in the clutch disc facings and places tremend
13. the free play at the clutch pedal Then road test the car Clutch Linkage Repair and Replacement Check the clutch linkage for proper operation One of the most common points of wear in the linkage is the pedal itself Bushings can wear or the mounting bracket bolts can loosen Always check these parts when servicing the clutch linkage or overhauling a clutch Figure 7 10 shows typical clutch pedal components Rod and lever linkage A rod and lever linkage usually wears at pivot points See Figure 7 11 Many pivot points contain metal or plastic bushings These bushings often wear out Sometimes linkage rods or levers will bend This may happen if something in the clutch causes excessive resistance in disengagement Another common cause of Stop screw Bushing Pedal Bushing support bracket Clutch f cable Guidh Bushing lever pedal and Pivot shaft pivot shaft locknut Brake pedal Figure 7 10 Study the exploded view of a typical clutch and brake pedal assembly The pivot points should be carefully checked and lubricated DaimlerChrysler Manual Drive Trains and Axles Clutch linkage rod Clutch pedal arm Ld M L Bellorank Lever Clutch arm fork lt R Clutch AY INS Clutch pushrod Figure 7 11 Notice the pivot points in this exploded view of a rod and lever linkage Most problems in this system are caused by wear misadjustment or lack of lubrication at the pivot
14. the hydraulic system has been opened air must be removed from the system The process of removing air is called bleeding To remove the clutch from a vehicle other compo nents must be removed In most cases the drive shaft assembly or drive axles must be disconnected from the vehicle The transmission and clutch housing are then removed to reach the clutch assembly 154 To remove the clutch assembly the clutch cover attaching bolts are removed from the flywheel Then the pressure plate assembly and clutch disc are removed from the flywheel The flywheel and pilot bearing should be checked for defects A worn or damaged pilot bearing should be replaced An overheated or warped flywheel can be resur faced by a machine shop The flywheel ring gear teeth should be checked for damage A damaged ring gear can be removed The replacement ring gear is installed by heating it and placing it over the flywheel The clutch disc is almost always replaced during a clutch teardown The disc can be checked to determine the cause of failure This may help avoid a similar clutch failure in the future Always check the new disc to make sure it is the proper replacement Many clutch problems after overhaul are caused by using the improper clutch disc The pressure plate assembly is usually replaced as part of a clutch overhaul Some assemblies can be rebuilt The rebuilding process requires the use of a press The throwout bearing should be checked
15. their seats as shown Screw the eyebolt adjustment nuts onto the eyebolts until their tops are flush Slowly release the arbor press and remove the assembly Height gauge Eyebolt adjustment 12 H Position the height gauge on the hub of gauge plate Turn the eyebolt adjustment nut until the lever is flush with the height gauge Adjust all levers in this manner Stake all adjustment nuts when finished so they will not loosen in service A straight edge can also be used and placed across the cover Levers can then be set to a height at some specified distance down from the straightedge Remove the clutch cover from the flywheel loosening the bolts gradually until spring pressure is relieved Replacement bearings must be pressed onto the col lar after the old bearing is removed To remove the throwout bearing press it from the collar using a bench vise or press Adapters may be necessary to properly per form the pressing operation Press on the new throwout bearing It should be fully seated on the shoulder of the bearing collar when complete Refer to Figure 7 33 Caution Do not apply driving force through Po the bearing elements when installing the throwout bearing 150 A Manual Drive Trains and Axles Figure 7 32 A Dry worn throwout bearing Riding clutch improper clutch adjustment B Worn front bearing retainer hub Bent fork or fork mount After the bearing is in place rotate it by ha
16. 35 Study the relative position of the clutch parts and the clutch pilot shaft Use of a clutch pilot shaft will make trans mission reinstallation much easier General Motors 152 Flywheel Tighten to holding tool specs with torque wrench O Tighten iN crisscross pattern in steps Pilot tool Figure 7 36 The clutch cover attaching bolts should be turned down gradually in a crisscross pattern Push up lightly on the pilot shaft during tightening This will ensure the disc holds its alignment Bolts should be torqued to specifications Once the bolts are tight remove the alignment tool Try sliding it in and out a few times to see that it does not bind If it does the trans mission will be difficult to install Toyota 5 Pack the inside of the throwout bearing collar with high temperature grease Typically collars have an outer groove for the clutch fork The groove should be lightly coated with grease Refer to Figure 7 37 Install the throwout bearing assembly on the fork Use clips or retaining springs to secure the bearing to the fork In cases where the clutch and transmission housings are one it will be necessary to slide the bearing assembly onto the hub of the front bearing retainer first See Figure 7 38 6 If the clutch housing was removed install it now A clutch housing that is integral with the transmission case is installed with the transmission Before instal lation check for dirt or paint that co
17. 40 the axles On other vehicles the drive axles can be removed without removing these parts This is covered in detail in Chapter 15 recently the engine and exhaust system will be hot Always be careful when work ing on a hot engine f Warning If the vehicle has been operated 4 Disconnect the pushrod or cable and return spring connected to the clutch fork 5 Remove the transaxle This is covered in detail in Chapter 11 On many vehicles the transaxle and clutch housings are a single unit Figure 7 20 If this is the case the complete unit is removed from the engine On vehicles requiring the engine also be removed for clutch replacement refer to the manu facturer s service manual Note that the transmission input shaft and front bearing retainer will be removed along with the transaxle In addi tion the clutch fork and throwout bearing assembly will be removed with the one piece or integral type casting Warning Support the engine with an A engine holding fixture when removing the transaxle This will keep the engine from dropping as you remove the transaxle and will protect the motor mounts Also use a transmission jack to support the transaxle Never let the transaxle hang unsupported once attaching bolts connecting the transaxle and clutch housings are removed This action can cause damage Flywheel Manual Drive Trains and Axles to the clutch disc splines or transmission inp
18. This sample chapter is for review purposes only Copyright The Goodheart Willcox Co Inc All rights reserved Chapter Clutch Problems Troubleshooting and Service After studying this chapter you will be able to UO Describe the common problems that can occur in a clutch assembly O Adjust a clutch Q Remove a clutch assembly Q Inspect clutch parts for wear and damage UO Remove and replace a flywheel and a pilot bearing Q Disassemble repair and install various clutch parts Q Install a clutch assembly Technical Terms Riding the clutch In car service Dumping the clutch Clutch adjustment Clutch drag Constant duty throwout bearing Clutch slippage Bleeder valve Grabbing clutch Radial runout Clutch chatter Lateral runout Clutch vibration 125 126 Introduction This chapter explains how to diagnose and service clutches Clutch problems and their causes are identified Procedures performed with the clutch in place such as clutch adjustment are covered Major repair and replace ment procedures which require clutch removal are also explained Clutch Problems and Troubleshooting You cannot properly service a clutch until you know what is wrong with it In many instances a clutch problem that seems to be severe is minor and easily remedied In other cases the solution involves replacing Clutch disc facing worn Engine flywheel friction surface warped or
19. abbing clutch engages with a jerk or shudder no matter how slowly and carefully it is applied The effect may be a series of jerks which is often described as buck ing This problem may be severe enough to cause damage to universal joints or other drive train parts If you suspect a grabbing clutch always check the engine and transmission or transaxle mounts before trou bleshooting the clutch Loose mounts can cause a sensa tion similar to a grabbing clutch Also make sure all clutch housing and transmission bolts are tight A grabbing clutch is usually caused by oil deposits disbursed on the friction facing of the clutch disc or by an overly hot or glazed facing Less common causes are worn splines on the clutch disc hub flange or transmission input shaft a warped clutch disc or warped pressure plate or flywheel machined surfaces Another possible cause is a worn or misaligned clutch fork This can cause the release bearing to become crooked or tip on its shaft The result is an uneven application of pressure on the pressure plate assembly The bearing collar may begin to wear because of the uneven pressure from the fork Clutch Chatter Clutch chatter is a specific type of vibration that is accompanied by a rapid clunking or rattling noise It occurs while the clutch is being engaged as opposed to while the clutch is fully engaged It is closely related to clutch grabbing It differs however in that it is heard more than it is felt
20. aced Throwout bearing assembly inspection Check the throwout bearing for roughness by attempt ing to rotate it by hand If rotation is rough or if it appears to have lost its grease it should be replaced Check the bearing collar for a free but not loose fit on the hub of the transmission s front bearing retainer A loose fit indicates that the collar or hub or both is worn Check the collar where it contacts the clutch fork If the Pressure plate Remove springs B Carefully mark positions of all springs and release levers This will ensure parts are reinstalled in their original positions Organize the disassembled parts of the pressure plate assem bly on the workbench Replace all parts that show wear Drive lug D Grease the pressure plate drive lugs with high temperature grease after inspecting assembly for cracking wear and other damage Figure 7 31 Procedures A through H illustrate the steps in a coil spring pressure plate assembly overhaul This procedure is general and the manufacturer s service manual should always be consulted General Motors continued Chapter 7 Clutch Problems Troubleshooting and Service 9 springs painted light 3 springs unpainted blue adjacent to levers 9 springs aao painted orange ba adjacent to levers E E To reassemble install the release levers and apply springs Basically install the release levers by reversing the procedure for removal If
21. aimlerChrysler 11 Loosen the clutch cover attaching bolts sequentially one turn at a time until all spring pressure is relieved If bolts cannot be reached use a flywheel turner to rotate the flywheel until each bolt is accessible Once pressure is relieved carefully remove the bolts and the pressure plate assembly Then remove the clutch disc and alignment tool from the flywheel heavy Make sure you can support its weight before removing the last bolt If a clutch align ment tool has not been used be aware that the clutch disc could fall out as the attaching bolts are removed f Warning The pressure plate assembly is fairly Also if the clutch was slipping it may be hot for a long time after the vehicle is stopped Be careful not to burn yourself on a hot pressure plate or flywheel 12 With the clutch removed check the engine to trans mission mounting surface for cracks and foreign material that would prevent proper engine transmis sion mating Also check the core freeze plugs at the rear of the engine block for corrosion leaks and proper installation Check the rear seal for oil leaks and damage If dowel pins are used for engine and clutch housing alignment check them for burrs or bending If there are no dowel pins ensure that they have not been lost Check the dowel pin holes for elongation and burrs Clutch cover Punch marks Flywheel Figure 7 19 To maintain the proper balance between th
22. any reasons It is normal for a clutch to wear out after 50 000 miles 80 000 km If a clutch wears out sooner there may be another problem that caused premature clutch failure The most common cause of early clutch failure is driver abuse Clutch problems can be divided into different groups The most common clutch problem is slippage Slippage 153 occurs when the clutch is engaged but does not transmit all of the engine power Slippage can be caused by a worn out clutch improper linkage adjustments or oil on the clutch facings Less common causes are a warped flywheel clutch disc or pressure plate or worn pressure plate apply springs A slipping clutch should be fixed before excess heat ruins other clutch parts Clutch vibration can be caused by loose or unbal anced clutch parts Loose parts usually also cause noise Sometimes what appears to be a clutch vibration is caused by loose engine mounts loose clutch mounting bolts or excessive crankshaft endplay Clutch noises are often caused by defective bearings The defective bearing can be isolated by operating the clutch pedal Depending on clutch pedal position the pilot bearing throwout bearing or transmission front bearing can be at fault Rattles and knocking noises are almost always caused by loose parts Clutch grabbing is usually caused by oil on the clutch facings Other possible causes are glazed clutch facings or wear and misalignment of the throwout bearing assemb
23. ard them Thoroughly clean all parts and allow them to dry Caution Do not allow any petroleum based solvent to remain on the cylinder or piston 4 Install the return spring when there is one in the cylinder Manual Drive Trains and Axles 5 Obtain new seals Make sure they are the correct ones Lubricate them with brake fluid never with petroleum based lubricants and install them on the piston 6 Install the piston in the cylinder Be careful not to damage the new seals 7 Install the retaining snap ring pushrod and boot 8 Install the rebuilt cylinder 9 Attach the hydraulic line There should be no air in hydraulic lines if there is it must be removed by bleeding the lines If the hydraulic system was dis assembled for any type of repairs you must bleed the lines to remove the air Once the bleeding operation is finished pressure on the pedal should apply the clutch firmly There should be no spongy pedal feel The slave cylinder has a bleeder valve for bleeding air from the system The valve looks like a screw with a small hole running down its length The hole is closed off when the bleeder valve is tightened down Loosening the valve a few turns will open the hole and permit sys tem bleeding Note that some bleeder valves have a cap as well There are two methods to manually bleed air from a hydraulic system One method is preferred over the other because it minimizes the chance of fluid contamination
24. ctions contain some general proce dures for removing a clutch from a vehicle Always refer to the appropriate service information for specific procedures Front Engine Rear Wheel Drive The following procedure details the proper way to remove a clutch from a front engine rear wheel drive vehicle 1 Disconnect the battery negative cable Figure 7 15 ground cable before working near the clutch Otherwise if the starter is acciden tally operated you could be severely injured f Warning Always disconnect the battery 2 Raise the vehicle with an approved hoist or hydraulic jack If using a hydraulic jack be sure to install good quality jack stands under the vehicle frame before getting under the vehicle 137 Disconnect battery Figure 7 15 The battery should always be disconnected at the ground terminal before beginning any clutch repairs If the battery is not disconnected there is always a possibility that the starter will be operated causing injury Subaru Warning Never work under a vehicle A supported only by a hydraulic jack Always support the vehicle with jack stands 3 Once the vehicle is properly raised and supported remove the drive shaft assembly Chapter 13 covers this in detail Cap the rear of the transmission to pre vent oil dripping See Figure 7 16 If the vehicle has four wheel or all wheel drive remove the front drive shaft from the transfer case recently the engine a
25. ctly opposite each other finger tightening them The clutch will now support itself Thread in and finger tighten the remaining bolts making sure all bolts are started properly Caution The bolts used to hold the pres sure plate assembly to the flywheel are high strength bolts Do not use low tension hardware store replacements as they will probably break and cause a clutch explosion Finish tightening the clutch cover attaching bolts by torquing them down gradually in a crisscross pattern Make sure the pilot shaft does not sag as you tighten the bolts Putting a slight upward force on the pilot shaft will help to retain the alignment of the clutch disc Finish tightening the bolts to the proper torque given by the manufacturer Once the bolts are tight ened make sure the clutch pilot shaft slides in and out freely See Figure 7 36 4 If so equipped lubricate the seat of the clutch fork ball stud in the clutch housing Use high temperature grease Install the spring clip in the fork Force the ball stud into the fork recess so that it is engaged by the clip If the clutch fork is the shaft type assemble by pass ing the release shaft through the clutch housing and clutch fork Lubricate the parts as necessary and lock them in place with the retaining E clip If lock bolts are used be sure to torque them properly Flywheel Pressure plate assembly Clutch alignment tool Clutch disc Figure 7
26. damaged Leaking rear main bearing seal Clutch pilot bearing worn Flywheel attaching bolts stripped or broken Clutch release bearing dry or worn Bearing collar unlubricated Loose broken or missing clutch cover attaching bolts Manual Drive Trains and Axles the clutch assembly or some other major component Check the easiest most obvious solutions such as clutch adjustment before removing the clutch Also look beyond the clutch for possible solutions Consider the possibility the problem is something other than the clutch Figure 7 1 shows typical clutch problems Study them carefully Clutch discs are like brake linings they gradually wear out as they operate Every time the clutch is engaged or disengaged some friction material is removed from the clutch disc The amount of material lost during each action is small and most clutches will last for 50 000 miles 80 000 km or more It is normal for a clutch to wear out after this mileage is reached Often however a clutch will not last as long as 50 000 miles Like any other mechanical part the clutch can be damaged by careless or abusive operation Further it can be damaged by outside factors factors that cannot be attributed to the vehicle operator It is important for Clutch pressure plate damaged or worn Release levers or fingers bent or worn Front bearing retainer hub dry or worn Clutch fork bent Leaking front bearing retainer
27. e reassembled flywheel and the pressure plate assembly make punch marks on both parts before disassembling This is necessary only if the pressure plate will be reused In many cases this completes clutch removal You should inspect the pilot bearing and flywheel outlined in upcoming paragraphs and determine if they must also be removed Front Engine Front Wheel Drive The following procedure details the proper way to remove the clutch from a front engine front wheel drive vehicle Note that with a few exceptions the general pro cedure cautions and warnings duplicate clutch removal for front engine rear wheel drive vehicles 1 Disconnect the battery negative cable ground cable before working near the clutch Otherwise if the starter is acciden tally operated you could be severely injured Warning Always disconnect the battery 2 Raise the vehicle with an approved hoist or hydraulic jack If using a hydraulic jack be sure to install good quality jack stands under the vehicle frame before getting under the vehicle supported only by a hydraulic jack Always Warning Never work underneath a vehicle support the vehicle with jack stands 3 Once the vehicle is properly raised and supported remove the drive axles There are several variations of front drive axle attachment On some vehicles the wheels and brake assembly along with certain steer ing and suspension parts must be removed to remove 1
28. e clutch pedal Ne C Causes instant heat buildup on clutch disc facings and places tremendous stress on the drive train D Is a form of clutch abuse Ner Clutch adjustment involves Each of the following operator actions can cause early Manual Drive Trains and Axles Vibration that occurs when the clutch is being engaged or disengaged is called A deep knocking noise that is similar to an engine main or rod bearing knock is an indication of A defective bearings B a loose clutch fork C weak retracting or cushion springs D loose flywheel attaching bolts A resurfacing the flywheel B C setting clutch free play D All of the above rebuilding the pressure plate assembly Why should you not let a transmission hang after removing its mounts Briefly cite two methods that may be used to remove a pilot bearing from the crankshaft bore The flywheel face and pressure plate should be cleaned with a n cleaner When inspecting a flywheel what trouble signs should you look for Briefly summarize typical steps involved in the clutch reassembly process for a front engine rear wheel drive vehicle ASE Type Questions Chapter 7 clutch failure except A riding the clutch pedal B C dumping the clutch D disengaging the clutch when decelerating overloading the vehicle Technician A says that light clutch drag can cause gear cla
29. e housing it should be checked for wear A Remove the retaining E clip B Remove the clutch release shaft DaimlerChrysler 1 Pilot bearing and flywheel installations were detailed previously in respective service sections As a prelim inary step recheck the pilot bearing and flywheel to make sure they are installed properly 2 Install the clutch disc and pressure plate assembly onto the flywheel If one side of the disc is marked flywheel place that side against the flywheel If not marked study the disc flywheel and assembly to determine which way the long side of the hub should fit into the assembled clutch It should be fairly obvi ous Use your alignment tool Figure 7 35 It will hold the disc in place and keep the disc hub aligned with the pilot bearing This way the input shaft will go in smoothly when you attempt to reinstall it Caution When handling clutch parts make sure your hands are clean It is important that no oil or grease contact the clutch disc D 151 Match holes in the assembly to flywheel dowels where applicable Otherwise align punch marks that you made during removal Some pressure plate assemblies will be aligned through offset bolt holes If none of these reference marks are available turn the pressure plate assembly on the alignment tool and align bolt holes with the nearest threaded holes in the flywheel 3 Begin threading in the clutch cover attaching bolts Install two dire
30. e only becomes worse Eventually the clutch disc becomes so badly worn that there is not enough friction present to move the vehicle A slipping clutch gets very hot The extreme heat damages the contact surfaces of the pressure plate and flywheel causing them to lose their proper finish This happens because the heat changes the chemical makeup of the metal reducing its strength and heat absorption capability A slipping clutch should be repaired before the pressure plate or flywheel is damaged by excessive heat A badly slipping clutch is usually too glazed and worn down to be fixed by adjustment A clutch disc that is too glazed cannot develop any driving friction between itself and the flywheel and pressure plate If the clutch disc is completely worn down the apply springs will not be able to apply enough pressure to the pressure plate to hold it tight against the flywheel The clutch must be replaced A clutch disc that is soaked with oil such as from a leaking rear main bearing seal will also slip In this case the clutch may not be worn down If the clutch disc is soaked with oil however it must be replaced A clutch often slips if the vehicle is driven through deep water This is because water enters the clutch hous ing and soaks the clutch disc The clutch will usually work normally after the disc dries Slippage can also be caused by disc pressure plate or flywheel contact surfaces that are warped If the surface is not p
31. e other is turned in the same direction to adjust the pushrod length Note that the pushrod slides through the hole in the pivot block 133 Locknuts Clutch fork attachment Adjusting threads Cable Cable sheath Bracket Figure 7 8 Adjusting free play in a cable linkage The end of the cable is threaded Loosening the locknuts and moving the cable makes the adjustment the clutch is worn out Note that in many vehicles with self adjusting clutch systems the throwout bearing is always in contact with the release levers or fingers Such bearings are called constant duty throwout bearings With the clutch pedal fully released the bearing makes light contact with the release levers or fingers Even so there is enough slack in the cable linkage to give some free play at the pedal If the clutch is the manually adjustable type use a ruler to measure the actual amount of free play at the clutch pedal Compare the amount against the manufac turer s specifications If the specs are not available you can assume that the free play is between 1 and 1 5 25 mm and 38 mm Also check that the cable and other linkage work freely and do not bind If the free play must be adjusted loosen the locknut holding the threaded portion of the cable sheath There are usually two locknuts holding the end of the cable to a bracket Leave the locknuts loose and alternately turn them until the cable length is correct Tighten the locknut
32. ease bearing Transaxle with integral clutch housing Figure 7 20 The clutch housing and transaxle case are usually combined into a single casting General Motors Chapter 7 Clutch Problems Troubleshooting and Service or damage Some technicians will automatically replace the bearing as a matter of practice If there is any doubt about a pilot bearing s condition it should be replaced Roller or ball type pilot bearings should be inspected for lack of lubrication To check this turn the bearing and feel for roughness If it does not turn smoothly it should be replaced In a pilot bushing wear will show up as looseness between the bushing and the input shaft pilot A good way to check for looseness is to insert a used input shaft into the bearing and try to wiggle it If it has too much play the bushing is worn out and it should be replaced Note To perform this check you must have the same type of input shaft as used in the vehicle transmission Bearing removal There are a couple ways to remove a pilot bearing One way is to use a pilot bearing puller tool as shown in Figure 7 21 One variation of this tool is the threaded tip puller The threaded tip puller is used to remove a pilot bushing but it ruins the bearing in the process The center shaft or pilot of this tool has a self tapping tip The pilot is threaded into the bore of the bearing When fully inserted the legs of the puller are adjusted to sea
33. erfectly flat and straight the flywheel or pressure plate will not make good contact with the disc As a result the disc may slip or chatter Warped surfaces may be caused by improper manufacturing processes or by exces sive heat Sometimes a clutch slips because the pressure plate apply springs are weak Weak springs may have been installed in the pressure plate assembly originally or the assembly may have been intended for a smaller engine or vehicle The springs may have become weak from over heating or under normal circumstances the springs may have become weak because of long usage A clutch pedal 129 that depresses with almost no effort may be a sign of weak clutch apply springs Clutch slippage can be caused by improper clutch linkage adjustment If the clutch linkage is adjusted to where there is no free play and the throwout bearing is applying pressure to the release levers or fingers the clutch will not be fully applied and it will slip Note that if the clutch fork return spring is discon nected the pedal will have no free play However this condition will not cause slippage When the clutch pedal is released after being applied the apply springs will fully re engage the clutch The throwout bearing will ride on the release levers or fingers but will not apply pressure on them to cause slippage Therefore do not confuse this con dition with the lack of free play caused by misadjustment Grabbing Clutch A gr
34. h is too much pedal free travel With excessive free travel the pressure plate may back off somewhat but it will still retain contact with the disc when the pedal is pushed to the floor Always check the clutch linkage adjustment when indications point to a dragging clutch Clutch Slippage Clutch slippage is a condition wherein the full power of the engine does not reach the transmission The engine Condition tO 1 NUTT OT d out of reverse gear freely in an Slipping Grabbing or Chattering Rattling Transmission Click Throwout Bearing Noise with Clutch Fully Engaged Pedal Stays on Floor When Released Hard Pedal Effort a Bind in linkage a Lubricate and free linkage b Driven plate worn b Replace driven plate Clutch Trouble Diagnosis Probable Cause J Aa Loose linkage Faulty pilot bearing Faulty driven disc Fork off ball stud Clutch disc hub binding on clutch gear spline Clutch disc warped or bent i Loose pivot rings in cover assembly Improve adjustment no lash Oil soaked driven disc c Worn facing or facing torn from disc d Warped pressure plate or flywheel e Weak diaphragm spring Driven plate not seated in Driven plate overheated Oil on facing Burned or glazed facings Worn splines on clutch gear Loose engine mountings Warped pressure plate or flywheel Burned or smeared resin on flywheel or pressure plate a Weak re
35. h disc Note that some bearings are prelubricated and do not require any additional lubrication Flywheel Service The flywheel is large and very heavy and removing it can be difficult and even dangerous It should not be removed unless it is in need of resurfacing It is rare to find a flywheel that is not showing some sign of wear or over heating Judgment is called for in deciding if it must be resurfaced In many cases the flywheel can be reused Crankshaft a Lightly grease recess l Pilot bearing Pilot bearing to be installed to spec distance j Figure 7 24 Grease the recess behind the pilot bearing but be careful to use only a small amount Lack of grease will allow the bearing to run dry and be damaged On the other hand too much grease will drip out and damage the clutch disc Ford Manual Drive Trains and Axles without machining If the flywheel is not badly worn it can be cleaned by light sanding Flywheel inspection Visually inspect the flywheel for obvious signs of dam age Check the flywheel machined surface for discoloration caused by overheating scoring or extremely shiny sur faces In some cases the flywheel may have deep heat cracks Look for warping Inspect the threads in the holes for the clutch cover attaching bolts If they are stripped they can be restored by installing a thread repair insert Also check the flywheel ring gear for damage If even one ring gear too
36. hear upon engaging the clutch will likely be coming from the transmission front bearing Chapter 7 Clutch Problems Troubleshooting and Service Dry throwout J bearing on Worn s 7 transmission front bearing amp Transmission input shaft A M Figure 7 4 Three bearings associated with the clutch are the pilot bearing the throwout bearing and the transmission front bearing Each can be detected as a source of noise by operating the clutch pedal Wear or lack of lubrication can cause the bearings to make noise Luk Worn pilot bearing 2 Push the clutch pedal only until all free play is removed This causes contact with the release levers or fingers allowing the throwout bearing to rotate without disengaging the clutch If you hear a noise in this position typically a whirring or grinding sound the throwout bearing is probably defective 3 Push the clutch pedal to the floor If a noise typically a squealing or howling sound occurs on disengage ment the pilot bearing is probably defective Sometimes the clutch assembly will have a rattle especially when the clutch is fully engaged and there is no foot pressure acting on the linkage A possible source of the rattle is a clutch fork that is loose on its pivot ball The rattle may be caused by too much clearance between the fork and the groove in the throwout bear ing A loose fit between parts of a rod and lever linkage or a missing tension spri
37. heel with a cutting torch or a metal saw Ring gears that are welded are commonly removed by breaking the welds with a chisel Those that are a shrink fit can be heated and then removed with a chisel See Figure 7 26A Warning Wear eye protection during ring gear removal gt If the new ring gear is to be installed by a shrink fit you can expand the gear by heating Figure 7 26B or shrink the flywheel by cooling Usually the easiest method is to heat the ring gear with a torch Try to heat the part evenly Once the ring gear is hot enough close to but not exceeding 450 F 232 C it can be placed over the fly wheel Figure 7 26C Caution Wear welding gloves when han dling the hot ring gear or handle it with tongs After the ring gear is placed on the flywheel it should be checked for proper seating Make sure the gear is not warped warpage will cause the starter to jam Once you have determined that the ring gear is properly installed stake it or weld it in place as necessary A cracked scored or severely overheated flywheel must be resurfaced A severely cracked flywheel must be replaced Be sure the replacement flywheel has its balance weights thickened areas on flywheel in the proper posi tion The easiest way to do this is to compare the old and new flywheels Therefore never dispose of the old fly wheel until reassembly is complete Resurfacing a flywheel is a job for a machine shop Generall
38. ing clutch disc damage and gear clash As a final check slip the replacement disc over the transmission input shaft to make sure it has the correct splines Pressure Plate Assembly Service The pressure plate assembly is another clutch compo nent that is almost always replaced when the clutch is repaired You should spend a few moments checking the pressure plate assembly This will help you determine the cause of the clutch problem and learn how it can be pre vented in the future Pressure plate assembly inspection The pressure plate machined surface develops the same problems as the flywheel surface Check for wear scoring signs of overheating cracks and warpage The pressure plate will usually show more heat damage than the flywheel Retaining rivets for diaphragm spring pivot rings should be checked for looseness Loose rivets indicate long usage or rough clutch treatment 145 Sliding caliper Measure clutch disc thickness and compare to specs A Sliding caliper Clutch disc facing B Figure 7 28 Inspecting the clutch disc A Clutch disc thick ness can be measured with a sliding caliper If thickness specifications are available the thickness can be compared to determine whether the disc can be reused B Depth gauge on sliding caliper or depth micrometer can be used to determine the distance from the top of the clutch disc rivets to the surface of the friction facing If the rivets are too near
39. l rule pressure plate assemblies that are put together with nuts and bolts can be rebuilt while pressure plates held by rivets cannot be rebuilt If a shop decides to rebuild a pressure plate assem bly it must closely follow the manufacturer s directions A general procedure for rebuilding a pressure plate assembly is shown in Figure 7 31 Remember to wear eye protection Throwout Bearing Assembly Service The throwout bearing is almost always replaced when the clutch is serviced It is often a source of problems If Arbor press Clutch cover Remove Block adjustment nuts A Use an arbor press to compress pressure plate apply springs so that the assembly can be taken apart Place and arrange the block under the pressure plate so that the cover is free to move down Remove the eyebolt adjustment nuts which are used to adjust the release lever height from clutch cover Slowly release the arbor press so the cover can be removed without the apply springs flying out Eyebolt pe 1 Release lever C Remove release levers To do this lift up on the lever and remove the strut Keep all parts of each particular lever together Manual Drive Trains and Axles the bearing must be reused it should be carefully checked for defects Caution If you intend to reuse a throwout bearing do not wash it in any kind of clean ing solvent Solvent will dissolve the throwout bearing lubricant which cannot be repl
40. locknut adjuster loosen the lock nut that holds the threaded rod to the pivot block Turn the rod until the proper free play is obtained at the clutch pedal and then retighten the locknut For the double lock nut adjuster loosen the one locknut depending on which way the adjustment is to be made Then turn the other locknut in the same direction advancing the pushrod until Chapter 7 Clutch Problems Troubleshooting and Service Bellcrank or relay rod Locknut Pushrod Flats for wrench Pushrod threaded through pivot block Figure 7 6 This shows a single locknut adjuster The locknut is loosened and the pushrod is turned in or out to obtain the proper free play the proper free play is obtained at the clutch pedal Retighten the first locknut Recheck the free play at the clutch pedal As a final check road test the car to check clutch operation Cable linkage adjustment The cable linkage uses a cable to connect the clutch pedal to the clutch fork Adjustment is made by a threaded section which passes through a bracket This section is located on the end of the cable linkage at the clutch fork See Figure 7 8 Some cables are self adjusting If there is no free play on a self adjusting clutch the adjustment mechanism is faulty or Bellcrank or relay rod Locknuts Pushrod Pushrod can slide through pivot block Figure 7 7 This shows a double locknut adjuster One locknut is backed away th
41. ly the problem is in the clutch assembly The two most common causes are a throwout bearing collar that is sticking on its hub or bind ing in the clutch fork This usually occurs after the vehicle has been operated in deep water causing water to enter the clutch housing and wash off the lubricant If the pedal is very hard to work after a new pressure plate assembly is installed the pressure plate apply springs may be stronger than necessary This is very common when a heavy duty or competition racing pressure plate is installed Return springs that are too heavy might be responsible for hard pedal effort Remember as you depress the clutch pedal you are working against return spring tension In Car Clutch Service Clutch service commonly requires the removal of major components such as the drive shaft assembly trans mission and clutch assembly However certain clutch problems can be attended to without removing these major components This type of service is categorized as In car service Clutch repairs that fall into this category are clutch adjustment and linkage repair or replacement Procedures are given in this section Clutch Adjustment Clutch adjustment involves setting the correct amount of free play in the clutch linkage Too much free play can cause clutch drag preventing the clutch from ever fully disengaging In this case the power flow is not completely cut off from the clutch and the engine could continue t
42. ly or clutch fork Clutch chatter is similar to grabbing but it is heard more than felt It can be caused by some of the same defects that cause grabbing Sometimes chatter is caused by a buildup of clutch dust on the friction facings A pedal that is hard to push may be caused by a binding condition in the linkage or a throwout bearing that is sticking on the front bearing retainer hub A new pressure plate assembly with excessively stiff springs may have been installed A clutch that does not release may have a defect in the linkage Rod and lever linkages or cable linkages may be broken or disconnected A hydraulic linkage may be out of fluid If the linkage checks out the problem is inside the clutch assembly In some cases the clutch disc may have welded itself to the flywheel or pressure plate All types of clutch linkage have some provision for adjusting the free play Free play is measured at the clutch pedal The usual free play measurement is between 1 and 1 5 25 mm and 38 mm The clutch linkage may need lubrication or repair Rod and lever linkages may require new bushings or realignment of linkage parts Cable linkages may have problems due to a corroded or kinked cable The cable must usually be replaced Hydraulic linkages can leak or the hydraulic lines can be kinked or swelled shut Leaks can be spotted by a visual examination Master and slave cylinders can be rebuilt if necessary After rebuilding or whenever
43. lywheel surface Dial indicator Read while rotating crankshaft Figure 7 25 Proper mounting of the dial indicator is important The base must be solidly attached to the rear of the engine Push on the flywheel to remove crankshaft endplay Position indicator so that plunger just touches the flywheel The dial is then zeroed Ford Chapter 7 Clutch Problems Troubleshooting and Service repeat this procedure at least three more times at different positions on the flywheel If any of the samples produce fluctuations exceeding 0 01 0 25 mm the flywheel must be resurfaced As mentioned the surface of the flywheel should also be checked for runout This is a condition of a rotating object such as a shaft or flywheel in which the surface is not rotating in a true circle or plane Radial runout is a measure of out of roundness It is measured at right angles to the centerline of an object Excessive radial runout may be caused for example by a bent shaft Lateral runout is a measure of in and out movement or wobble It is mea sured in the direction that is lengthwise to the centerline of the rotating object In other words it is measured on the plane surface of the rotating object Excessive lateral runout can result for example if a flywheel is not mounted properly To check for lateral runout slowly rotate the flywheel while watching the dial indicator Determine the lowest point on the flywheel which corresponds to
44. ncerned hard pedal effort is due to lack of lubrication or to some part of the linkage that is bent or loose enough to jam Sometimes a rock or other material gets thrown up and jams the linkage Clutch pedals of cable linkages usually are hard to depress because moisture has entered the cable sheath Moisture washes out the cable lubricant and causes corro sion It is also possible that the cable was misrouted during installation and needs rerouting If the cable is kinked as a result of misrouting it should be replaced Clutch pedals of hydraulic linkages are hard to depress because of master cylinder or slave cylinder problems The piston sometimes sticks due to internal corrosion The usual cause however is swollen piston seals This problem is a result of using a petroleum based oil such as automatic transmission fluid instead of brake fluid DOT 3 or DOT 4 to refill the reservoir Petroleum based oils will cause the seals to swell jamming the piston in the cylinder When this occurs the seals must be replaced A less common cause of hard pedal effort in a hydraulic system is a swollen hydraulic hose If the hose swells so that the fluid passageway becomes fairly constricted it will take longer to actuate the slave cylinder piston The swollen hose will slow clutch disengagement It will also slow clutch reengagement and pedal return If the clutch linkage worked as it should when it was disconnected that is if it moved easi
45. nd and make sure it rotates smoothly It should turn without bind ing or roughness Clutch Fork Service A bent or worn clutch fork can prevent the clutch from releasing properly Inspect the clutch fork for such signs of damage Look for wear at the throwout bearing mount On lever type clutch forks check the pivot point contact area Inspect the spring clip that holds the clutch fork to the pivot point On shaft type clutch forks check the pivot shaft for wear If inspection reveals a damaged clutch fork the fork must be removed if it is not already and replaced The lever type clutch fork is removed when the clutch is Driver Press ram Bearing Driver Bearing Removing Installing collar collar A B Figure 7 33 Replacing a throwout bearing A The throwout bearing can be removed from its collar by using a press The proper adapter must be used In many cases the bearing can be removed and replaced by using a bench vise B This illus trates the bearing installation procedure Be careful not to exert any pressure on the rolling elements or outer race Toyota disassembled The shaft type clutch fork can be removed by first removing the pivot or clutch release shaft The shaft is usually held by a clip Figure 7 34A Once the clip is removed the shaft will slide out of the housing and the fork can be removed from the shaft Figure 7 34B With the fork assembly apart you can also check the pivot shaft f
46. nd exhaust system will be hot Always be careful when working on a hot engine Warning If the vehicle has been operated 4 Disconnect the pushrod or cable and return spring connected to the clutch fork 5 Remove the transmission Chapter 9 covers trans mission removal in detail On many vehicles the clutch housing and transmission case are com bined in a single casting In such cases the clutch housing is removed along with the transmission by removing the unit from the back of the engine Note that the transmission input shaft and front bearing retainer are removed with the transmission In addition the clutch fork and throwout bearing assembly are removed with the one piece or integral type casting If the vehicle has a transfer case the transmission and transfer case can be removed as a unit 138 Remove drive shaft 4 SS A Rear axle housing Cap or plug yah Lf ir f Ne Extension Tt housing Vy as W N B Figure 7 16 The first steps to remove a clutch A Remove the drive shaft assembly B Cap the transmission extension housing to prevent oil loss Oil leakage can create a safety hazard Subaru the transmission Usually the transmission provides some support for the engine Removing it removes this support Warning Support the engine when removing Also use a transmission jack Figure 7 17 to sup port the transmission Never let the transmission hang unsupported once
47. ng and Service a Clevis pin mounting bracket 135 Clutch cable lever Throw out lever Clutch housing Figure 7 12 This is a typical cable linkage A replacement cable must be routed so that it does not seize or bind The original routing is normally the best DaimlerChrysler Clutch pedal pushrod Clutch fluid bent or off reservoir empty Leaking slave cylinder RS Leaking feed line i Ske Internal leak __ in clutch e master cylinder Smashed or leaking pressure line Figure 7 13 Common sources of hydraulic linkage problems are shown The pushrod for actuating the master cylinder pis ton may be bent or disconnected but most problems are caused by low fluid level or by plugged hydraulic lines Leaks are usually responsible for low fluid levels Kinks can cause plugging of hydraulic lines Ford replacement cylinder is not available or the cost of replacement is excessive If a new or remanufactured mas ter or slave cylinder cannot be located the old cylinder can be rebuilt with the proper seal kit Rebuilding a master or slave cylinder is relatively simple It is similar to rebuilding brake system cylinders Refer to the exploded views of typical master and slave cylinders in Figure 7 14 Following is a typical rebuilding procedure 1 Remove any rubber boot that covers the free end of the piston 2 Remove the snap ring that holds the piston in the
48. ng can cause the mechanism to rattle It may be possible to tighten the clutch fork retainer clips or springs to reduce clearances and quiet the linkage Rattles can also be caused by weak pressure plate retracting springs in the diaphragm spring pressure plate 131 assembly or by weak or broken clutch disc cushion springs Rattles stemming from these problems are usually loudest when the clutch is disengaged Loose flywheel attaching bolts cause movement at the mounting surfaces of the crankshaft and flywheel This movement causes a deep knocking noise that is often mistaken for an engine main bearing or rod bearing knock The noise may be accompanied by vibration It can usually be reduced by disengaging the clutch Pressure from the throwout bearing acting through the release levers or fingers and the clutch cover press the flywheel tightly against the crankshaft quieting the knock Hard Pedal Effort Hard pedal effort is noticed when the clutch pedal is excessively hard to push down If the pedal is hard to depress the problem is usually in the linkage If the driver is strong enough to depress the pedal it may stay on the floor or rise very slowly when released Components may wear quickly To isolate the cause of the problem disconnect the clutch linkage at the clutch fork and try to move the pedal by hand If the clutch pedal does not move easily the problem is somewhere in the linkage Where rod and lever linkages are co
49. ng contacts pressure plate assembly Maximum pedal position Freeplay Floorboard Figure 7 5 Free play can be measured using a ruler The amount of free play should match the manufacturer s specifica tions A general check can be made by observing the pedal movement The throwout bearing first contacts the pressure plate assembly at the point where resistance is first felt when pressing on the pedal Note A slipping clutch that is badly worn or damaged cannot be repaired by adjust ment If adjustment does not stop clutch slipping or if enough free play cannot be obtained indicating worn parts the clutch assembly must be removed and worn parts must be replaced Rod and lever linkage adjustment A rod and lever linkage is a series of links levers and rods connecting the clutch pedal to the clutch fork Adjustment is usually provided by a threaded rod that passes through a pivot block Figure 7 6 and Figure 7 7 An adjustment device is located on the linkage at the clutch fork To adjust a rod and lever linkage measure the actual amount of free play at the clutch pedal and compare it to specifications Use a ruler to make an accurate measure ment If the specifications are not available 1 25 mm of free play is usually close Before attempting to make the adjustment check that the linkage is not worn excessively A loose sloppy linkage cannot be satisfactorily adjusted Next for the single
50. ntegral type clutch housing was removed with transmission To do this remove the clutch access cover from the front of the housing Then remove the clutch housing attaching bolts clutch housing to engine bolts Vacuum any dust inside the housing Note that housing removal is not necessary in every case In some vehicles the clutch assembly may be removed through an opening provided by removal of a clutch access cover 9 If the pressure plate assembly and flywheel do not have dowels or offset bolt holes for alignment pur poses use a punch to mark the original position of the clutch cover relative to the flywheel Beforehand vacuum any dust from the clutch Typical punch marks are shown in Figure 7 19 10 Insert a pilot shaft or clutch alignment tool through the clutch disc hub and into the pilot bearing if desired This will keep the clutch disc from falling out of the pressure plate assembly as the clutch cover attaching bolts clutch cover to flywheel bolts are being removed Note that an old transmission input shaft makes a good pilot shaft Chapter 7 Clutch Problems Troubleshooting and Service Pull Front of housing 0 7 Ball stud Throwout bearing Clutch housing Ball stud Push Clutch fork Spring clip Figure 7 18 Clutch forks that pivot on a ball stud are usually held in place by a spring clip Remove the clutch fork by push ing the inner end forward and pulling on the outer end D
51. ntly replaced or appears to be in excellent condition it can be reused Before deciding to reuse the disc it should be carefully checked breathing any dust from the clutch disc as it can contain large amounts of cancer causing asbestos Even new clutch discs often contain some asbestos Warning Asbestos dust is harmful Avoid If you intend to reuse the clutch disc do not wash it in any kind of cleaning solvent Solvent will ruin the clutch disc friction facings Inspect the clutch disc for thin or cracked friction material The disc thickness can be checked with a slid ing caliper as shown in Figure 7 28 Usually however other indications will be obvious and this step will be unnecessary Check the disc for loose rivets oil soaked friction facings or broken cushion springs Make sure the hub flange splines are not worn and they slide freely on the splines of the transmission input shaft If the clutch disc shows any wear or damage it should be replaced Figure 7 29 shows various types of clutch disc damage you might find during inspection along with possible reasons damage occurred If a replacement disc is to be used it must be carefully compared to the old one before it is installed Many clutch problems are caused by installing the wrong replacement disc It is especially important to check the hub flange size against the old disc A hub flange that is too large will contact the flywheel and pressure plate caus
52. o propel the vehicle Too little free play can cause the clutch to slip In this case the throwout bearing rotates continually as it contacts the rotating pressure plate release levers or fingers and it quickly wears out With enough pressure on the levers or fingers the clutch slips overheats and becomes damaged No matter what type of clutch linkage is used the free play can be checked by pushing the clutch pedal with your hand Refer to Figure 7 5 and the next few paragraphs for the proper procedure Begin with the pedal in a fully released position that is with the pedal all the way up Start pushing down on the pedal The pedal should move easily for about 1 25 mm In this span the only pressure you are working against is that of the return springs Past this point the pedal becomes harder to push This is where the throwout bearing contacts the pressure plate release levers or fingers and you are working against the force of the pres sure plate apply springs The distance that the pedal moved from the fully released position until it became hard to push is the free play All vehicle manufacturers specify the proper amount of clutch free play Free play is adjusted at some place on the clutch linkage On many vehicles the clutch has a self adjusting feature that automatically adjusts free play whenever the clutch pedal is depressed Manual Drive Trains and Axles Firewall or bulkhead Throwout beari
53. only C Both A and B D Neither A nor B Each of the following is caused by improper clutch adjustment except A clutch drag B C grabbing clutch D clutch slippage throwout bearing wear Technician A says that a badly slipping clutch usually cannot be fixed by adjusting the linkage Technician B says that free play at the clutch pedal should be measured before attempting to adjust the clutch link age Who is right A A only B B only C Both A and B D Neither A nor B Opening the slave cylinder bleeder valve while press ing on the clutch pedal will cause the pedal to A slowly rise B become hard to push C go to the floor D lock up Clutch Problems Troubleshooting and Service 11 155 A pilot shaft is used to align the pilot bearing and the pressure plate A B C D Ner clutch disc w S C input shaft Ner throwout bearing Technician A says that one should never work under a vehicle that is supported only by a hydraulic jack Technician B says that jack stands should always be placed under a vehicle that has been raised on a hoist Who is right A A only B B only C Both A and B D Neither A nor B Technician A says that pilot bearings should be care fully checked once the clutch is removed Technician B says that the flywheel should not be removed unless it is damaged or needs resurfacing Who is right
54. oose pressure plate fasteners A clutch explosion destroys all clutch components and often breaks the clutch housing A clutch used for racing will often have a scatter shield installed over the clutch housing This keeps flying clutch components from entering the passenger compartment Abnormal Noise Often the clutch is blamed for a noise when some other component is at fault Any vehicle component can become noisy under the right conditions An abnormal noise in the clutch can usually be singled out by applying or releasing the clutch pedal If the clutch is the source of the noise this will have some effect on the noise being made Rumbling squealing whirring or grinding noises can be caused by a defective transmission front bearing throwout bearing or pilot bearing A defective transmis sion front bearing will commonly make noise as the clutch drives the input shaft whenever the clutch is engaged A defective throwout bearing makes noise as the bearing is applied A noisy pilot bearing is usually heard when the clutch is disengaged completely It will not usually make noise when the clutch is engaged since the crankshaft and input shaft are turning at the same speed Figure 7 4 Follow these procedures to isolate defective bearings 1 While depressing the clutch pedal start the engine and leave it running With the transmission in Neutral release the clutch pedal taking your foot completely off the pedal Any noise that you
55. or wear Clutch Housing Service Clutch housings usually are not a source of problems It is important however that they be inspected for damage Clean the clutch housing interior and exterior Then check the housing for cracks and damage to mount ing surfaces Any damage is grounds for replacement Also check the clutch fork ball stud for wear It should be undamaged and tight If the stud must be replaced it can usually be removed from the clutch housing with a large Allen wrench or a differential plug removal tool Clutch Installation The following section presents the general procedures for installing a clutch safely and properly The exact proce dure for clutch installation varies according to the engine and drive train layout You should always refer to the man ufacturer s service manual for specific procedures and techniques to install a clutch safely and properly Front Engine Rear Wheel Drive The following procedure details the proper way to install a clutch in a front engine rear wheel drive vehicle Chapter 7 Clutch Problems Troubleshooting and Service Front bearing retainer hub Clutch ON release bearing Transmission fi LA El tch Clutch release release shaft Ge o fork Bushing Clutch release E clip Clutch release fork release lever Figure 7 34 This type of clutch fork uses a shaft mounting It must be disassembled to remove the fork When the shaft is out of th
56. ous stress on the clutch and the entire drive train Clutches usually do not last very long under this type of abuse Overheated clutch facings a result of dumping the clutch can become glazed within seconds This form of abuse can also cause flywheel clutch cover or clutch housing attaching bolts to shear off Further it can cause clutch disc hub splines to be stripped or input shafts to break Placing more load on a clutch than it is designed to handle can also be a source of damage An example is starting off in high rather than in low gear Shifting into a higher gear before the engine has reached the proper rpm also overloads the clutch as does attempting to change gears at very high engine speeds Another example is over loading the vehicle to the point that the clutch must be allowed to slip heavily when starting off just to get the vehicle moving This is a common problem on vehicles used for towing As stated outside factors can also cause clutch damage Oil leaks from the engine rear main bearing seal or from the transmission front bearing retainer seal can reach the clutch disc If the disc gets contaminated with oil it grabs or chatters when engaged If enough oil gets on the disc it slips at all times and the disc surfaces soon wear out from the resulting friction If the disc becomes com pletely saturated with oil the surface does not wear out but the disc itself becomes useless Finally many clutch problems are d
57. points General Motors problems is a bellcrank that binds or is loose because of worn motor mounts or misalignment of the engine in the vehicle The linkage must be restored to perfect operating condition before the clutch will operate properly This may involve lubrication adjustment or replacement of linkage parts Cable linkage Cable linkage problems are usually due to a seized or binding cable assembly Cables can seize due to corrosion or lack of lubrication A cable may seize or bind if it is caused to kink in its sheath from improper routing Defective cables should be replaced If a cable must be replaced make sure you route it so there is no possibility of seizing or binding Use all the original cable brackets and mounting locations if possible A typical cable arrangement is shown in Figure 7 12 Hydraulic linkage Before adjusting a hydraulic linkage always check the fluid level in the master cylinder reservoir first If the fluid level is low check for leaks at the places indicated in Figure 7 13 Leaks appear as dark stains on hydraulic sys tem parts Sometimes the brake fluid used in the system is visible at the point of the leak Leaks can occur in the hydraulic lines or at loose connections The most common leaks however occur at the master or slave cylinder seals It is usually easier and cheaper to replace leaking master and slave cylinders However in some cases a Chapter 7 Clutch Problems Troubleshooti
58. r expelled fluid Chapter 7 Clutch Problems Troubleshooting and Service which may be contaminated is returned to the system The method is outlined as follows 1 Open the bleeder valve by loosening it about a quarter or half turn 2 If the bleeder valve has a cap remove it at this time Attach a hose to the end of the open bleeder valve Place the free end of the hose in a clear container of brake fluid 3 Fill the system reservoir with fresh brake fluid and replace the cap 4 Pump the clutch pedal until bubbles stop coming out of the hose in the container You might want to have an assistant watch for the bubbles for you to make the job easier 5 With the clutch pedal released close the bleeder valve Clutch Removal The exact procedure for clutch removal varies according to the engine and drive train layout On vehi cles with rear wheel drive and on many vehicles with front wheel drive the transmission and clutch are removed from the vehicle without removing the engine On some front wheel drive and on most rear engine vehicles the engine clutch and transaxle are removed from the vehicle as an assembly When removed from the car the components are separated to expose the clutch assembly On other front wheel drive vehicles the engine and clutch are removed leaving the transaxle in the vehicle On a few vehicles the clutch can be removed and replaced without removing any other components The following se
59. r problems Who is right B only Both A and B Neither A nor B A A only B B only Both A and B C D Neither A nor B 19 20 Manual Drive Trains and Axles A clutch makes a grinding sound as the clutch pedal is depressed and the engine is running Each of the following could cause the problem except A misadjusted clutch linkage B oil or grease on the clutch C D warped pressure plate warped clutch disc A driver complains that the clutch is not working properly The car is equipped with a hydraulic link age An inspection shows that the slave cylinder is not responding to pedal action Fluid level is all right Technician A says to try bleeding the hydraulic system first Technician B says to replace the seals in the system first Who is right A A only B B only Both A and B C D Neither A nor B
60. s and recheck the free play at the clutch pedal Then road test the car and check clutch operation Hydraulic linkage adjustment The hydraulic linkage uses hydraulic pressure to transfer pedal movement to the clutch fork As with the previous adjusters adjustment is made by a threaded section on the linkage at the clutch fork Adjustment to this linkage changes the effective length of the pushrod at the slave cylinder See Figure 7 9 Hydraulic Threaded Locknut Clutch line pushrod Adjuster fork Dust boot Figure 7 9 Adjusting free play in a hydraulic linkage The pushrod is often threaded Shortening or lengthening the rod adjusts free play The pushrod is held by a locknut Measure the amount of free play at the clutch pedal Use a ruler to obtain an accurate reading and compare it against specifications If the specifications are not avail able between 1 and 1 5 25 mm and 38 mm of free play is generally acceptable Before adjusting free play check the master cylinder reservoir to make sure the fluid level is sufficient Add DOT 3 brake fluid if necessary Caution Never add motor oil transmission fluid or any kind of petroleum based oil to the master cylinder reservoir Use brake fluid only to prevent major damage to seals D Loosen the locknut holding the threaded rod to the adjuster Turn the rod until you obtain the proper free play as measured at the clutch pedal Retighten the locknut Recheck
61. shing Technician B says that clutch disc spindown can be mistaken for clutch drag Who is right A A only B B only C Both A and B D Neither A nor B Technician A says that some clutch slippage is neces sary for smooth shifts Technician B says that an oil soaked clutch disc will slip even if it is not worn Who is right A A only B B only C Both A and B D Neither A nor B Chapter 7 Each of the following can cause clutch slippage except A excessive pressure plate apply spring pressure B C worn clutch disc D warped flywheel or pressure plate surfaces misadjusted linkage Technician A says that clutch grabbing and clutch chatter are the same condition Technician B says that clutch vibration or chatter could be caused by broken engine or transmission mounts Who is right A A only B B only C Both A and B D Neither A nor B If a noise is heard when the clutch pedal is completely released up position with the engine running which of the following bearings is probably defective A Engine rear main bearing B Clutch pilot bearing C Throwout bearing D Transmission front bearing Technician A says that automatic transmission fluid can be used to refill a hydraulic clutch linkage reser voir Technician B says that kinked clutch linkage cable can be lubricated to restore normal operation Who is right A A only B B
62. spring Normal fatigue insufficient clearance adjustment ment damaged input shaft bad pilot bearing binding linkage loose or soft motor mounts worn driveline parts wrong clutch for vehicle low quality pressure plate 4 i a oan yn RA ol C Worn disc facing Weak pressure plate springs normal D Damaged hub splines Transmission drawn into place with C Pressure plate hot spots or heat checks Clutch slippage ee ee wear scored or cracked flywheel bellhousing bolts oil or grease contamination clutch adjustment too tight binding bad release bearing improper part alignment linkage driving habits iE E T a a a WE eae P URET O AA ORENA ENORA E Scored pressure plate Clutch disc worn to rivets adjust F Broken diaphragm spring Installation error excessive bad pressure plate reused a ie ment too tight clutch slippage binding linkage pedal reserve causing throwout bearing to travel too far during disengagement Figure 7 29 Study the types of clutch disc damage Luk Figure 7 30 Study the types of pressure plate assembly damage Luk 148 Pressure plate assembly repair Most repair shops choose to completely replace pres sure plate assemblies rather than rebuild them It is possi ble however with the proper equipment to take apart a pressure plate assembly and replace just the parts that are worn This is typically done on an assembly line by large automotive rebuilders As a genera
63. stalled by driving them in squarely with a soft faced mallet A special tool with a shoulder is needed to drive hollow dowels Drive the dowels in carefully until they are fully seated If there was a spacer plate between the flywheel and the crankshaft flange reinstall it before replacing the flywheel Align the crankshaft flange and flywheel bolt holes They are usually spaced so they will line up at only one location After the bolt holes are aligned start the flywheel attaching bolts Torque the bolts to the proper tension in a crisscross pattern Figure 7 27 Use a flywheel holder or a wood block to hold the flywheel during the tightening operation Caution Do not tighten the bolts with an impact wrench The bolts must be torqued properly Flywheel resurfacing The flywheel is held to the crankshaft flange with special hardened bolts Do not use any other kind of bolt Be careful not to accidentally swap the flywheel attaching bolts with any others Flywheel holder Sea r Eoy crisscross pattern Figure 7 27 Torque the flywheel attaching bolts in a crisscross pattern Be sure to use the proper bolts and torque them to specification Do not use an impact wrench to tighten the bolts Honda Chapter 7 Clutch Problems Troubleshooting and Service Clutch Disc Service In most cases the clutch disc is replaced when any kind of clutch teardown is done since it is relatively inex pensive If the disc was rece
64. t on the crankshaft flange As the tool is tightened further it pulls the pilot bearing from the crankshaft bore Another variation called an expandable finger tip puller is a similar tool used when ball or roller bearings are used Special puller Flywheel Pilot bearing Figure 7 21 The pilot bearing removal tool will make pilot bear ing removal easier DaimlerChrysler 141 Another way to remove the old pilot bearing is to pack the recess behind the bearing with heavy grease Then install a driver into the pilot bearing an old input shaft works nicely Put on eye protection and strike the exposed end of the input shaft with a hammer The force from the hammer will travel through the input shaft to the grease The grease will push the bearing from the crank shaft See Figure 7 22 Bearing installation Before installing the new pilot bearing slip it over the pilot of the transmission input shaft This is done to ensure it is the proper bearing If it will not slip over the shaft or if the fit is too loose it is not the correct bearing The next step is to drive the new bearing into the crankshaft bore Figure 7 23 Use a properly sized driver to avoid damage Measure the installed depth of the pilot bearing If this depth is too shallow the input shaft may contact the bearing This will damage the bearing the input shaft or both If the bearing is driven in too deeply it may not make full contact with the input shaf
65. t pilot This is not a problem with bushings as they are usually longer If bushings are driven in too deeply there is still usually adequate surface contact with the input shaft pilot Once the pilot bearing is properly installed lubricate it with a small quantity of high temperature grease Most bearings have a recess behind the bearing A small amount of grease stored in this recess will find its way to the bear ing surface helping to keep it supplied with lubricant See Figure 7 24 Engine crankshaft flange j Bushing forced out by grease Hammer blows Old input shaft Grease builds pressure on rear of pilot bushing Heavy grease packed inside bore Figure 7 22 A pilot bearing can also be removed by packing grease into the recess behind the bearing A driver is then placed into the pilot hole and struck The driver moves into the grease creating pressure The pressure drives out the bearing 142 crankenat OP flange 4 l EY Clutch pilot bearing DA R Driving tool Figure 7 23 A new pilot bearing should be installed with the proper bearing driver Use a driver that contacts the outer race only when driving a roller or ball type pilot bearing Always be very careful to avoid damage when installing a new bearing Ford Caution Do not put too much lubricant on the bearing or in the recess Excess lubri cant will be thrown out of the pilot bearing and can ruin the clutc
66. th is broken the ring gear must be replaced Note that if the ring gear teeth are damaged you should also check the teeth of the starter drive pinion for damage If the flywheel is not obviously damaged use a straightedge and feeler gauge to check for warped contact surfaces Manufacturers specifications as to maximum warpage vary As a general rule if more than a 0 01 0 25 mm feeler gauge fits under the straightedge the flywheel must be resurfaced A dial indicator also can be used to check for a warped flywheel In addition it can be used to check the flywheel runout Push the flywheel toward the engine to remove crankshaft endplay Then mount the dial indicator on a stationary part of the engine with the indicator point bearing on a smooth relatively undamaged part of the machined fly wheel surface as shown in Figure 7 25 Rotate the flywheel and watch the dial to determine how much fluctuation in val ues there seems to be which would give an indication of warping If rather than a series of fluctuations the dial shows a steady increase for half a turn and then a steady decrease flywheel runout may be excessive In either case the fly wheel must be removed and resurfaced or repositioned To check warpage zero the dial indicator then slowly turn the flywheel through about a quarter of a revolution Watch the indicator face and note if displacement ever exceeds 0 01 0 25 mm Without moving the indicator fA F
67. the input shaft and clutch disc splines use the transmission output shaft to turn the input shaft It may be necessary to slightly shift or wiggle the transmission to get the input shaft through the clutch disc and into the pilot bearing If the pilot shaft was used properly the input shaft should enter the clutch assembly without too much difficulty Caution If the transmission shows any sign of oil leakage through the front bearing retainer correct the leak before installing the transmission If the clutch housing is part of the transmission bolt the unit to the back of the engine If the clutch hous ing is separate bolt the transmission case to the housing Start the attaching bolts as soon as the input shaft is slid into place and the mating housing Chapter 7 Clutch Problems Troubleshooting and Service surfaces are flush This will keep the transmission from hanging and damaging the clutch hub splines or the input shaft Caution Do not use the bellhousing or transmission case attaching bolts to try to draw in a binding transmission This could bend the clutch disc hub or break the bellhousing or transmission case ears Also the transmission input shaft could damage the pilot bearing If the clutch and pilot bearing are installed correctly the trans mission should slide fully into place by hand 8 Reconnect the pushrod or cable and return spring connected to the clutch fork Then adjust repair or replace
68. the linkage as outlined earlier in this chapter Install any other parts such as the speedometer cable shift linkage or connector wires 9 Reinstall the rear drive shaft assembly as detailed in Chapter 13 If the vehicle has a front drive shaft install it now After the drive shaft or shafts are installed ensure all other drive train connections are made 10 Check the transmission lubricant and add fluid if necessary Reconnect the battery negative cable Lower the vehicle and perform a road test During the road test make sure there is no slippage the clutch engages and disengages smoothly and the free play is correct Operate the clutch at least 25 times to properly seat the clutch mating surfaces Do not over heat the clutch during this time Front Engine Front Wheel Drive With a few exceptions the general clutch installation procedure for front engine front wheel drive vehicles duplicates clutch installation for front engine rear wheel drive vehicles Drive axles are replaced instead of the drive shaft assembly Reinstalling the several variations of front drive axles is covered in detail in Chapter 15 Also in the previous section substitute references to the transmission with transaxle Installing the transaxle is covered in detail in Chapter 11 On vehicles requiring that the engine also be removed for clutch replacement refer to the manufac turer s service manual Summary Clutches can develop problems for m
69. the lowest reading on the dial Zero the indicator at this point Move the flywheel until the highest reading is recorded This measurement is the lateral runout Lateral runout should not exceed the manufacturer s specifications If it does the flywheel may not be mounted properly Remove it and check for burrs between the fly wheel and the face of the crankshaft flange If no burrs exist check the runout of the crankshaft flange Note that while the dial indicator is mounted you can also measure crankshaft endplay Push the flywheel for ward and rearward and note the displacement on the dial Flywheel removal The easiest way to remove the flywheel attaching bolts is with an impact wrench If you do not have an impact wrench to remove the flywheel it must be kept from rotating so the attaching bolts can be loosened While the bolts are being removed the flywheel can be held in place using a flywheel turner or locked in place with a fly wheel holder alternatively a block of wood can be placed between the flywheel and a stationary part of the engine Warning Always wear eye protection when using an impact wrench A flywheel is very heavy It can cause injury or severe damage if dropped Do not remove the bolts completely until you have the flywheel secured so that it cannot fall Once the flywheel is securely held the bolts can be loosened and the flywheel can be removed Sometimes there is a flat metal spacer between the
70. tracting springs b Release fork loose on ball stud or in bearing groove c Oil in driven plate damper d Driven plate damper spring failure a Improper adjustment No lash b Release bearing binding on trans mission bearing retainer c Insufficient tension between clutch fork spring and ball stud Fork improperly installed e Weak linkage return spring a Worn release bearing b Fork off ball stud heavy clicking Pilot bearing loose in crankshaft a Bind in linkage or release bearing b Springs weak in pressure plate c Springs being over traveled Figure 7 2 Clutch diagnosis chart General Motors Manual Drive Trains and Axles Correction VD qT I H 1 I VU c Replace as necessary d Replace bearing e Replace disc f Install fork onto stud Lightly lubricate fingers at release bearing Also lube bearing I D groove Repair or replace clutch gear and or disc Replace disc runout should not exceed 0 020 i Replace plate and cover assembly a Adjust linkage to spec b Install new disc and correct leak at its source Replace disc Replace pressure plate or flywheel Replace pressure plate Be sure lash is checked before replacing plate Make 30 to 40 normal starts CAUTION Do Not Overheat Allow to cool check lash Install new disc and correct leak Replace transmission clutch gear Tighten or replace mountings Replace pressure plate or fl
71. ue to lack of maintenance or careless service If the clutch linkage is not adjusted and lubricated on schedule or if the throwout bearing or clutch hub splines are not properly greased during installation the moving parts may hang up or operate slowly The clutch is subjected to undesir able slippage shortening its life Slippage and other problems exhibited in clutch operation are presented in detail in the upcoming paragraphs Figure 7 2 summa rizes some common conditions and their causes and corrections 127 Clutch Drag If the clutch cannot be disengaged or it fails to release you cannot shift gears In this situation when you stop the vehicle in gear clutch pedal depressed the engine stalls This condition is known as clutch drag Clutch drag varies in degree Slight drag when the clutch pedal is fully depressed may tend to make the car creep when in gear or cause gear clash when the gears are first engaged The two most common causes of slight drag are improper linkage adjustment and lack of lubrication at the moving parts of the linkage In some cases the car creeps during the clutch spindown wherein the disc continues to spin for several seconds after being disengaged To determine if this is causing the creeping and not clutch drag a simple test can be performed if the transmission is not fully synchro nized Depress the clutch pedal shift into Neutral and wait about 30 seconds Then shift into an unsynchronized
72. uld throw the housing out of alignment As you tighten the clutch Coat this groove Throwout bearing Pack this recess Figure 7 37 If the throwout bearing is not lubricated properly it will bind on the hub of the transmission s front bearing retainer or it will wear rapidly Apply the proper type of grease to the places shown DaimlerChrysler Manual Drive Trains and Axles Move fork o iY CA l CA CH Input shaft eee CCK for free ie movement a _id Clutch fork J C Bearing retaining clip Figure 7 38 n this design the bellhousing is an integral part of the transmission housing The throwout bearing is placed on the front bearing retainer hub The clutch fork is installed and then the bearing is secured to the clutch fork Once assembled the clutch fork and bearing are checked for smooth operation Note how the bearing attaches to the clutch fork in this design variation DaimlerChrysler housing attaching bolts make sure wires or other vehicle components do not get pinched between the housing and the engine block Tighten the bolts in a crisscross pattern and torque them to the manufac turer s specifications 7 Using a transmission jack install the transmission as outlined in Chapter 9 sliding the input shaft into engagement with the throwout bearing where clutch housing is separate clutch disc splines and pilot bearing To align
73. ure the clutch housing to the engine and to the transmission just to make sure they are not loose Thoroughly check the drive shaft assembly drive axles and engine mounts Closely inspect conventional or constant velocity joints for any signs of wear In rare cases internal problems in the transmission or differential or the transaxle may cause vibration while the vehicle is moving Refer to later chapters related to these components If the vibration also occurs with the vehicle stopped transmission in Neutral the source of the problem is related to the clutch or the engine Check the engine for a dead cylinder or other internal problem Vibration result ing from excessive crankshaft endplay can be identified by disengaging the clutch Pressure from the throwout bearing will push the flywheel and crankshaft forward taking up the endplay and eliminating any corresponding vibration If the engine is okay look for problems indirectly related to the clutch First however check the clutch hous ing where it attaches to the engine and to the transmission Check the front bearing retainer where it attaches to the transmission Ensure all bolts are tight Figure 7 3 Look at the transmission front bearing as a possible cause of vibration Inspect the clutch assembly if the previously men tioned checkpoints have failed to identify the source of vibration There are two general sources of clutch vibration Q A part associated with the clutch
74. ut shaft Make sure for this and other safety reasons that you support the transaxle at all times If a transaxle were to fall it could cause injury or damage From here the clutch removal procedure duplicates that for front engine rear wheel drive vehicles To com plete clutch removal continue with step 6 of that section Clutch Parts Inspection and Repair With the clutch removed each component must be carefully inspected for wear and damage Be sure all parts are clean before inspection Clean the flywheel face and pressure plate with a nonpetroleum based cleaner Do not wash the throwout bearing in any kind of solvent Do not get grease on the clutch disc facings Look for any signs of damage or wear no matter how slight After the defect is identified the concerned part s may be repaired or replaced Service procedures for the var ious related parts of the clutch are the focus of this section Pilot Bearing Service A worn pilot bearing will allow the transmission input shaft and clutch disc to wobble This can cause clutch vibration a noisy clutch and damage to the transmission Pilot bearings are relatively cheap and they are easy to change while the clutch is being serviced Bearing inspection The clutch pilot bearing is not serviced until the clutch is removed The bearing is often worn out by then The pilot bearing should be inspected for excessive wear Friction disc Pressure plate assembly Clutch rel
75. y speaking any machine shop that can resurface cylinder heads can resurface a flywheel The machining process for flywheels is similar to that for cylinder heads Flywheels can be resurfaced by turning on a lathe including a brake lathe cutting on a milling machine or grinding on a table with a special grinding wheel No mat ter what method is used the basic process is the same material is removed until the surface is totally clean and damage free Only a certain amount of metal can be removed however If too much is removed the flywheel will not have sufficient metal to absorb heat Some flywheels are marked to indicate the maximum amount of metal that can be removed If the flywheel is not marked the machine shop will usually be able to tell you if there is enough good metal left in the flywheel As a general rule about 0 2 5 mm can be removed from a flywheel that has not been machined before Manual Drive Trains and Axles Note If you placed alignment marks on the flywheel face they will be removed during lt lt the machining process Make a duplicate mark at the exact spot on the back of the flywheel Some flywheels have alignment dowels These dowels should be removed before the flywheel is sent to the machine shop for resurfacing Flywheel installation Once the flywheel is resurfaced it should be rein stalled in its original position First reinstall any alignment dowels Solid dowels are in
76. ywheel Sand off if superficial replace burned or heat checked parts Replace pressure plate Check ball stud and retainer Replace driven disc Replace driven disc a Adjust linkage Clean relubricate check for burrs nicks etc Replace fork Install properly Replace spring Replace bearing Install properly and lubricate fork fingers at bearing See Section 6 for bearing fits Lubricate and free up linkage and release bearing Replace pressure plate c Adjust linkage to get proper lash be sure proper pedal stop bumper is installed Chapter 7 Clutch Problems Troubleshooting and Service speeds up but the vehicle speed does not increase as it should The clutch disc is not being gripped firmly and it slips between the flywheel and pressure plate as the members rotate Note In this section we are referring to abnormal clutch slippage For smooth shifts some degree of slippage is desir able The clutch pedal should not be released too quickly A controlled release will permit some slippage As a result you will not ruin the clutch or other parts of the drive train In addition it makes the ride easier on the vehicle occupants Clutch slippage begins as a minor problem At first it will occur on initial and hard accelerations As the problem progresses slippage will occur on upshifts down shifts and on any kind of acceleration Left uncorrected slippag

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