Service Manual Trucks - Heavy Haulers RV Resource Guide
Contents
1. Nm 369 55 ft Ib for M20 or 575 500 75 Nm 50 Nm 424 37 ft Ib for M22 369 55 ft lb M22 Note Use the crossover method 575 50 Nm see pattern above to evenly tighten the U bolt nuts Torque nuts in approx imately 100 Nm 75 ft Ib increments until full torque is obtained 424 37 ft lb 5 Road test the vehicle to seat compo nents then re torque the U bolt nuts 6 Re perform the procedure Volvo Air Suspension Ride Height and Driveline Angle Check Calculation and Adjust ment page 20 If axle pinion angles are still outside the specifications pro ceed with Method 2 Group 726 Volvo Air Suspension Method 2 1 W7000752 Support the nose of the axle with an adeguate jack AN DANGER Failure to properly support the nose of the axle may result in the axle rolling forward Personal injury hazard Never work under or around a raised vehicle unless it is securely supported on jack stands of adeguate rating Failure to use ade guate jack stands can result in the vehicle falling which can cause serious injury or death to anyone un der the vehicle 2 Loosen the U bolts enough to allow the bottom plate to be slightly free from the axle housing Lower the jack slightly approximately 10 12 mm 0 38 0 50 in 3 Snug up the U bolt nuts so that there is no movement in the bottom plate Service Procedures 4 Hand torque the U bolts to 500 75 M20 Nm 3692. Forward Axle Pinion Angle to Frame Check page 25 Note If after the second attempt the axle pinion angles are still not within specification perform the U bolt Torque Procedure page 26 as a last attempt to correct the axle pinion an gles 25 Group 726 Volvo Air Suspension U bolt Torque Procedure Loosening and re torquing the suspension U bolts in a particular sequence can influence the axle pinion angle Both U bolts on the left and right side on the same axle must be loosened and re torqued See Guidelines for Working on the Volvo Air Suspension page 19 before performing this procedure Method 1 preferred 1 W7000752 Support the nose of the axle with an adeguate jack AN DANGER Failure to properly support the nose of the axle may result in the axle rolling forward Personal injury hazard Never work under or around a raised vehicle unless it is securely supported on jack stands of adequate rating Failure to use ade quate jack stands can result in the vehicle falling which can cause serious injury or death to anyone un der the vehicle 2 Loosen the U bolts enough to allow the bottom plate to be slightly free from the axle housing Lower the jack slightly approximately 10 12 mm 0 38 0 50 in 26 Service Procedures 3 Snug up the U bolt nuts so that there is no movement in the bottom plate FRONT W7000750 Hand torque the U bolts to 500 75 M20
3. W7000757 Place an inclinometer or recom mended tool on top of the frame Zero out inclinometer or recom mended tool ANGLE A ANGLE B ANGLE C FWD AXLE INTERAXLE REAR AXLE PINION SHAFT ANGLE PINION ANGLE P RELATIVE TO FRAME ANGLE D ANGLE E FWD AXLE JOINT REAR AXLE JOINT WORKING ANGLE WORKING ANGLE W7000743 W7000252 Measure the forward axle angle P using the zero d out inclinometer or recommended tool Service Procedures 3 The angle P measurement must be within the specified range as shown in the following table Forward Axle Angle Relative to Frame P Axle Model Specification in degrees Tandem 6x4 2 5 0 1 Single 4x2 3 52 1 If angle P is outside the specifica tions it must be corrected Check for the following e Excessively worn wear plates pads Note Wear plates pads must be replaced in pairs left and right on same axle see Wear Plate Pad Replacement page 40 e Damaged spring hanger frame bracket e Damaged air spring Z spring and or radius spring e Damaged link rod e Broken loose U bolts e Faulty leveling valve Replace the components as neces sary then adjust the suspension ride height see Volvo Air Suspension Ride Height Adjustment page 28 4 Repeat all steps in Air Suspension Ride Height Check Calculation page 21 Interaxle U joint Angle Cancella tion Check Calculation page 22 and
4. 55 ft Ib for M20 or 575 500 75 Nm 50 Nm 424 37 ft lb for M22 369 55 ft lb M22 Note Torquing one U bolt before the 575 50 Nm other can influence the axle pinion an 424 37 ft lb gle Torquing the nuts on the U bolt on the rear side of the axle housing left and right first can decrease the axle pin ion angle Torquing the nuts on the U bolt on the front side of the axle housing left and right first can increase the axle pinion angle 5 Road test the vehicle to seat compo nents then re torque the U bolt nuts 6 Re perform the procedure Volvo Air Suspension Ride Height and Driveline Angle Check Calculation and Adjust ment page 20 27 Group 726 Volvo Air Suspension Volvo Air Suspension Ride Height Adjustment 1 The suspension ride height is raised or lowered by adjusting the link rod length Note If the vehicle is equipped with a non adjustable fixed length rod it must be replaced with an adjustable link rod before performing this proce dure See Link Rod Replacement page 31 W7000710 1 Clamp 2 Washer Remove the clamp from the lower end of the link rod Remove the nut and disconnect the lower end of the link rod from the crossbeam pedestal plate The upper end of the link rod should remain mounted to the leveling valve arm during the adjustment procedure 3 Install a new clamp on the rubber mount on the lower end of the link rod Note If
5. DANGER Personal injury hazard Never work under the vehicle unless the front wheels are securely chocked Failure to chock the wheels can result in the vehicle rolling which can cause serious injury or death to anyone un der the vehicle Service Procedures W7000752 Support the nose of the axle with an adeguate jack AN DANGER Failure to properly support the nose of the axle may result in the axle rolling forward Personal injury hazard Never work under or around a raised vehicle unless it is securely supported on jack stands of adequate rating Failure to use ade quate jack stands can result in the vehicle falling and or rolling which can cause serious injury or death to anyone under the vehicle 43 Group 726 Volvo Air Suspension W7000744 Remove nuts from rear U bolt Loosen bolts from front U bolt but do not re move 4 Remove lower shock bracket from U bolt 5 Remove lower shock mounting bolt and remove lower shock bracket Installation 6 Install shock bushings and lower shock mounting bolt Torque bolt to 60 10 Nm 44 7 ft lb Note When replacing shocks use only Volvo approved components shocks and bushings 7 Install lower shock bracket Install U bolts and snug up 8 Torque fasteners to 500 75 Nm 369 55 ft lb for M20 or 575 50 Nm 424 37 ft lb for M22 Note To ensure proper torque refer to U bolt Torque Procedure p
6. Operation Numbers Group 726 Volvo Air Suspension General Description er aaa TATA IL rang ne E E ES de 9 Ge HEG y th i RS S A F ERES P Q 8 9 x z A This information covers specifications service proce dures ride height adjustments and calculations and pinion angles for the Volvo Air Suspension Information in this manual is essential to maintain proper serviceabil ity and proper ride height set by the manufacturer for the Volvo Air Suspension The Volvo Air Suspension is set at the factory Chang ing the ride height will affect the driveshaft angles and may cause driveline vibration and or shorten compo nent life Ride height adjustments must be performed in ac cordance with all service manual procedures General W7000753 Group 726 Volvo Air Suspension Specifications Specifications Rear suspension Air Ride fastener torque specifications STD 38K 6x4 500 75 Nm 369 55 ft lb U Bolts for Suspension M22 STD 40K 6x4 4x2 Radius Spring to Spring Hanger Bracket 275 45 Nm 203 33 ft Ib Air Spring Crossbeam Pedestal to Leaf 105 20 Nm 77 15 ft lb pring po dd to Bracket Upper and 60 10 Nm 44 7 ft lb ower Bracket for Leveling Valve to Frame 60 10 Nm 44 7 ft lb Leveling Valve to Bracket 10 1 5 Nm 7 1 ft lb Leveling Valve Control Arm to Lever on Valve M6 10 1 5 Nm 7 1 ft lb and Air Bag Pedestal
7. height see Volvo Air Suspension Ride Height Adjustment page 28 6 Remeasure the ride height using steps 4a d of this procedure Repeat as nec essary until the measurement is within specifications 7 Proceed to Interaxle U joint Angle Cancellation Check Calculation page 22 22 Service Procedures Interaxle U joint Angle Cancella tion Check Calculation 4 The steps from Air Suspension Ride Height Check Calculation page 21 must be performed before continuing with this procedure Note All angle measurements are rel ative to level ground ANGLE A ANGLE B ANGLE C FWD AXLE INTERAXLE REAR AXLE PINION SHAFT ANGLE PINION RIDE HEIGHT ANGLE D ANGLE E FWD AXLE JOINT REAR AXLE JOINT WORKING ANGLE WORKING ANGLE W7000742 W7000252 Measure the forward axle angle A using an inclinometer or recommended tool Record the measurement for calculation refer to Volvo Air Suspen sion Calculation Form page 51 Note Wipe surface clean of dirt and debris before taking measurement Group 726 Volvo Air Suspension W7000756 Measure the interaxle shaft angle B using the recommended tooling Record the measurement for calcula tion refer to Volvo Air Suspension Calculation Form page 51 Note Wipe surface clean of dirt and debris before taking measurement 4 Calculate B A D The interaxle angle minus the forward axle angle will give the value D ref
8. Bracket Replacement Removal 1 Remove any wires or air line clippings from torque rod W7000716 Remove the two 2 bolts through torgue rod at frame rail side bracket 3 Remove the two 2 bolts through torgue rod at axle housing bracket and remove the torgue rod 4 Remove the four 4 fasteners to the torgue rod bracket at the frame rail and remove the bracket Note These may be Huck style fas teners which require additional effort for removal Heating the suspension components and frame rail may weaken them Hot surfaces can also cause seri ous burns 38 Service Procedures Installation 5 Install four 4 bolts to torque rod bracket at frame rail Note Use only approved fasteners 6 Install two 2 bolts through torque rod at axle housing bracket 7 Install two 2 bolts through torque rod at frame rail side bracket 8 Torque the bolts to torque rod and torque rod bracket to 320 50 Nm 236 37 ft Ib 320 50 Nm 236 37 ft lb 9 Re attach any wires or air line clip pings to the torque rod Group 726 Volvo Air Suspension Spring Hanger Frame Bracket Replacement Removal 1 W7000720 Remove the retaining pin and isolator spring roller from spring hanger frame bracket located under hook end of Z spring Note Follow the Guidelines for Working on the Volvo Air Suspension page 19 Service Procedures W7000718 Place jack stands on each s
9. and the leg of the spring hanger frame bracket to keep the Z spring centered during the U bolt nut torque procedure 15 Torque U bolt nuts to 500 75 Nm M20 369 55 ft lb for M20 or to 575 50 500 75 Nm Nm 424 37 ft Ib for M22 369 55 ft lb M22 Note To ensure proper torque refer 575 50 Nm to the U bolt Torque Procedure page 424 37 ft lb 26 16 Tighten the nuts for crossbeam mount 105 20 Nm ing bolts to the Z spring Torque to 77 15 ft lb 105 20 Nm 77 15 ft lb 17 Raise the vehicle and remove jack stands supporting frame rails 18 Crank the truck to build air pressure to raise the air suspension Note Ride height and pinion angle may require adjustment See Volvo Air Suspension Ride Height and Drive line Angle Check Calculation and Adjustment page 20 Group 726 Volvo Air Suspension Air Spring Removal and Instal lation Removal 1 Support the frame maintaining the ap proximate normal ride height Deflate air springs 2 Remove air lines from air springs N DANGER Pneumatic components store compressed air and can separate violently during disassembly or removal Be fore servicing any part of the pneumatic air system completely release the air pressure Failure to do so can result in serious personal injury or death W7000719 Remove the 2 upper frame bolts and bottom nut 4 Remove the air spring from the chas sis 5 Remove the
10. chocked Failure to chock the wheels can result in the vehicle rolling which can cause serious injury or death to anyone un der the vehicle Service Procedures 3 Dump release the suspension air see Dump Switch Operation page 15 AN DANGER Stay clear when suspension air is released Chassis may drop quickly and can cause serious injury or death to anyone under the vehicle W7000725 Jack the vehicle from under the rear of the Z spring at the crossbeam pedestal plate mounting until there is sufficient gap between the wear plate and Z spring to remove the wear plate Note Jacking both the left and right sides simultaneously will help obtain a sufficient gap Also lifting and prop erly supporting the rear of the chassis may increase the size of the gap 5 Remove the split pin and the retaining pin holding the wear plate into the spring hanger frame bracket 6 Pry out the old wear plate 41 Group 726 Volvo Air Suspension Installation 7 Install the replacement wear plate into the spring hanger frame bracket Note The thick end of the wear plate is always positioned to the rear of the vehicle 8 Install the retaining pin and a replace ment split pin into the spring hanger frame bracket to hold the installed wear plate 9 Remove the supports and lower the vehicle to the ground 10 Crank truck to build air pressure to raise the air suspension 11 Install the isola
11. crimp or tighten the clamp at the lower end of the link rod at this time 31 Group 726 Volvo Air Suspension W7000745 W7000710 1 Clamp 2 Washer 10 1 5 Nm 7 1 ft lb Install link rod Note position of washer Torque both nuts to 10 1 5 Nm 7 1 ft Ib Note Mount in same hole in the crossbeam pedestal as the original link rod Do not crimp or tighten clamp at lower end of the link rod at this time 32 Service Procedures 5 When completed crank the truck to build up air pressure to check the ride height see Air Suspension Ride Height Check Calculation page 21 The ride height must be within the fol lowing specifications e Low frame outside rail height di mension approx 266 mm 10 5 in 196 216 mm 7 75 8 5 in e High frame outside rail height di mension approx 300 mm 11 75 in 179 199 mm 7 0 7 75 in See Volvo Air Suspension Ride Height Adjustment page 28 6 Crimp or tighten clamp at the lower end of the link rod Group 726 Volvo Air Suspension Crossbeam Pedestal Plate Replacement Removal 4 Raise the rear suspension and support the frame with jack stands maintaining the approximate ride height Dump re lease the suspension air to relieve pressure off the air springs AN DANGER Stay clear when suspension air is released Chassis may drop quickly possibly causing serious injury to anyone under the vehicle 2 Remove the
12. fitting from the air spring Service Procedures Installation 6 Install the fitting in the air spring 7 Install the air spring back onto the frame and crossbeam pedestal plate 8 Torgue frame mounting bolts to 320 50 Nm 236 37 ft lb 9 Torgue lower nut to 50 10 Nm 37 7 5 ft lb 320 50 Nm 236 37 ft lb 50 10 Nm 37 7 5 ft lb Over torque will damage air spring 10 Install the air lines into the air springs 11 Crank truck to build pressure to inflate the air suspension Remove supports from frame 12 Check ride height see Volvo Air Suspension Ride Height and Driveline Angle Check Calculation and Adjust ment page 20 47 Group 726 Volvo Air Suspension Pneumatic switch replacement Note Make certain the vehicle ignition is OFF before beginning this procedure Removal W3000649 Remove the ashtray from the ashtray housing Remove the 2 screws from the ashtray housing and remove the housing 2 Once the ashtray housing is removed the air switch panel can be removed from the dash Pull the air switch panel away from the dash and to the left to clear the tip inserts W3000656 Disconnect the 2 terminal connectors from the cigar lighter and the electrical LED connections on the switch being replaced 48 Service Procedures AN DANGER Never disconnect an air system component unless all system pressure has been depleted Failure to de
13. to re placement valve Torgue to 10 1 5 Nm 7 1 ft lb 10 1 5 Nm 7 1 ft Ib Group 726 Volvo Air Suspension Installation 8 Lay the valve in the frame and install the air lines 9 Install the bolts through the frame and 60 10 Nm the valve bracket Torque bolts to 60 44 7 ft lb 10 Nm 44 7 ft lb 10 W7000713 10 1 5 Nm 7 1 ft lb Connect the link rod onto the arm Torgue the rod to 10 1 5 Nm 7 1 ft Ib 11 When completed crank the truck to build up air pressure to check the ride height see Air Suspension Ride Height Check Calculation page 21 The ride height must be within the fol lowing specifications e Low frame outside rail height di mension approx 266 mm 10 5 in 196 216 mm 7 75 8 5 in e High frame outside rail height di mension approx 300 mm 11 75 in 179 199 mm 7 0 7 75 in See Volvo Air Suspension Ride Height Adjustment page 28 Service Procedures Link Rod Replacement Removal 1 Dump release the suspension air see Dump Switch Operation page 15 AN DANGER Stay clear when suspension air is released Chassis may drop quickly and can cause serious injury or death to anyone under the vehicle 2 Unbolt link rod from leveling valve arm and crossbeam pedestal Remove from vehicle Installation 3 Pre set the length of the replacement link rod to approximately 505 mm 19 88 in Note Do not
14. 00712 Top plate 11 Group 726 Volvo Air Suspension Air Spring The air spring in the Volvo Air Suspension system is a rolling lobe sleeve type with a composite piston The air spring uses a single stud to attach to the crossbeam Do not mix the air springs of the Volvo Air Suspension with air springs of earlier suspensions System failure may result Link Rod The Volvo Air Suspension uses a link rod that is factory adjusted and set to accurately control the dimensions of the air springs prevent inappropriate adjustments and avoid unnecessary servicing Leveling Height Valve The leveling valve was designed to simplify the chassis air suspension system The quick dump valve is now combined into the height control valve This eliminates one valve and the related plumbing The valve is located on the left side of the frame rail ad jacent to the fifth wheel The Volvo Air Suspension height valve incorporates an integrated dump feature that eliminates the need for a separate valve and allows the rear to be lowered to back under a trailer 12 Design and Function W7000754 W7000759 Group 726 Volvo Air Suspension Shock Absorber Bracket Lower The lower shock absorber bracket on the Volvo Air Sus pension has been redesigned to eliminate the need for left hand and right hand versions Shock Absorber Bracket Upper The upper shock absorber bracket has been redesigned to eliminate the need for l
15. 8 Special Tools This air line release tool part no J 42189 may be used to safely disconnect air lines from switches This tool is available from Kent Moore telephone 1 800 328 6657 Other Equipment The following tools can be used to ensure proper inclina tions and or angles on the Volvo Air Suspension The Anglemaster is a digital inclinometer available from Dana Spicer telephone 419 535 4300 The J38460 A is a digital protractor available from Kent Moore telephone 800 328 6657 The J38460 25 may be used along with the Kent Moore digital protractor or the Dana Spicer digital inclinometer for checking pinion angles It is available from Kent Moore telephone 800 328 6657 W7000250 W7000726 Group 726 Volvo Air Suspension Design and Function Design and Function General RAR S o e d rt IA Rees A y NE EN AK epe y E 2 N W7000753 The Air Ride Suspension has been refined by Volvo Trucks North America The result of this refinement process is the Volvo Air Suspension The Volvo Air Sus pension is a rear air suspension with improved ride and increased durability Ride height has a direct relationship with driveline pinion angles It is very important that the ride height specifica tions recommended by Volvo Trucks North America are maintained The Volvo Air Suspension is set at the factory Chang ing the ride height will
16. A Order number PV776 TSP27725 1 O 97 Volvo Trucks North America Inc Greensboro NC USA All rights reserved No part of this publication may be reproduced stored in retrieval system or transmitted in any forms by any means electronic me chanical photocopying recording or otherwise without the prior written permission of Volvo Trucks North America Inc Contents ET A a i i i a i 3 RM a i i a o UIRE EN E 3 FONN asis iki ee 5 Rear suspension Air Ride fastener torque specifications 5 EN 5 Susp nsion APDIICATONS rene 6 TN orn E ii os ia i i i i E 7 ie ie OE pr 7 E skaniai i A 7 Design and Function ciar 9 FN E i i i a 9 Volvo Air Suspension Components c occcccccnnnoccnncccnnncononononannnnnnnnnnanennnnss 10 A NG 10 EV ee 10 A ER KEENE NE 10 EEE EE 10 NN A 11 A A O 11 OM A 11 TE PIE asilais dis i ii RE 11 ES 0 A AO 12 NS 12 NNN iniciada 12 Shock Absorber Bracket Lower ss 13 Shock Absorber Bracket Upper ooooccncccccocccconccoconcononocnnancnnnononannnns 13 o enone etry i i i i i i i i L 13 Prieumate Switeh BAME V eiii 14 Dump Switch Operation serio is 15 ee go ansia ir 17 Troubleshooting the Volvo Air Suspension mmmrrrrvrrrnnerrreenrnnnerevnennnn 17 Service Procedures corran ia 19 Guidelines for Working on the Volvo Air Suspension Ls 19 Volvo Air Suspension Ride Height and Driveline Angle Check Cal culation and ASL avila usais laca 20 Air Suspension Ride Height Check Calcu
17. NA FOR OPTIONAL GIRGUITS AIR SLIDE 5 WHEEL INTERAXLE DIFFLOCK INTERWHEEL DIFFLOCK ALB BIDE BEAR SUSPENSION mu DUMP SYSTEM AIR SUSPENSION SYSTEM SPRING SPRING AIR SUPPLY pe E MAME 00000 dv 4 FRONT u OUT Uli AS zei E fo FRAMERAIL mm AIR SUSPENSION CHASSIS ACCESSORY MANIFOLD LEVELING VALVE i I SPRING SPRING o Y of oNp oyo Se gt E LER A wees W7000700 PE Volvo Air Suspension 15 16 Group 726 Volvo Air Suspension Troubleshooting Troubleshooting the Volvo Air Suspension Bottoming Out Ride Height Incorrect Low Air Pressure Cause U joint angle incorrect Improper phasing of drivelines Axle inclination incorrect Worn wear plate Worn radius arm bushing Improper ride height Broken or defective Z spring Thrust alignment incorrect Improper wheel run out or balance Broken or loose U bolts Excessive wheel bearing end play Mismatched wheels and tires Broken or defective shock absorber Defective leveling valve Overloaded vehicle Pressure regulator set too low Wrong air spring Improper ride height Broken or defective spring Low air pressure Thrust alignment incorrect Worn or defective torque rod bushing Worn radius arm bushing Broken or loose U bolts Broken or defective spring Total wheel alignment incorrect Lateral alignment of axles incorrect Defective leveling valve Ride height not set properly Axle inclination i
18. NGLE W7000743 MEASUREMENTS 1 MEASURE THE RIDE HEIGHT Ride Height must be within specifications for the following frame types Low outside rail height dimension approx 266 mm 10 5 in 196 216 mm 7 75 8 5 in High outside rail height dimension approx 300 mm 11 75 in 179 199 mm 7 0 7 75 in If ride height is not within specification it must be corrected before continuing 2 MEASURE FORWARD AXLE ANGLE Relative to the ground BG FG ss ER 4 CALCULATE B A so S Bel CU er The difference between B and A is value D 5 MEASURE THE REAR AXLE ANGLE Relative to the ground 6 CALCULATE C B The difference between C and B is value E 7 CALCULATE D E ACTION LOWER RIDE HEIGHT No Adjustment RAISE RIDE HEIGHT Note The Air Suspension ride height cannot fall outside the specified tolerance If the adjustment for angle F requires that the air suspension ride height be adjusted outside the specified range see Troubleshooting the Volvo Air Suspension page 17 SPECIFICATIONS NGLE RELATIVE TO FRAME Tandem 6x4 25 0 1 ANGLE RELATIVE TO FRAME Tandem 6x4 2 5 0 1 Single 4x2 Note If angle P is not within tolerance see Troubleshooting the Volvo Air Suspen sion page 17 53 54 Operation Numbers VOLVO Volvo Trucks North America Inc P O Box 26115 Greensboro NC 27402 6115 Volvo Trucks Canada Ltd 6490 Vipond Drive Mississauga On
19. Service Manual Trucks Group 72 Volvo Air Suspension VNL VNM PV776 TSP27725 1 WVOlLYVO Foreword The descriptions and service procedures contained in this manual are based on de signs and methods studies carried out up to November 97 The products are under continuous development Vehicles and components produced after the above date may therefore have different specifications and repair methods When this is believed to have a significant bearing on this manual supplementary ser vice bulletins will be issued to cover the changes The new edition of this manual will update the changes In service procedures where the title incorporates an operation number this is a refer ence to an S R T Standard Repair Time Service procedures which do not include an operation number in the title are for gen eral information and no reference is made to an S R T The following levels of observations cautions and warnings are used in this Service Documentation Note Indicates a procedure practice or condition that must be followed in order to have the vehicle or component function in the manner intended Caution Indicates an unsafe practice where damage to the product could occur Warning Indicates an unsafe practice where personal injury or severe damage to the product could occur Danger Indicates an unsafe practice where serious personal injury or death could oc cur Volvo Trucks North America Inc Greensboro NC US
20. Spring Hanger Bracket to Frame 320 50 Nm 236 37 ft lb Pinion angle specifications AXLE PINION ANGLES SECOND AXLE SECOND AXLE apie en 52 in spacing 60 in spacing Eaton 23080 23105 Meritor Rockwell RS 23 160 RS 23 186 Eaton D404 Meritor Rockwell RT 40 145 Note Second tandem axle pinion angle may vary be cause of frame slope These are nominal angles Group 726 Volvo Air Suspension Suspension Applications Maximum Maximum GAWR GCW Metric Ton Ib Metric Ton Ib 9 20 000 1 17 88 000 000 50 110 000 18 40 000 Suspension Configuration 1 All 6x4 applications at 18 metric ton 40 000 Ib and all Ax2 applications require 22mm diameter U bolts as standard Also 6x4 applications at 18 metric ton 40 000 Ib require heavy wall axle housings All 6x4 vehicles de livered outside the United States require 22mm U bolts minimum and the heavy wall axle housing minimum regardless of the suspension rating di Er 1320 52 1320 52 FOUR 18 1 Meritor Rock 40 000 well a 1524 60 FOUR Specifications Required Number Available Axles of Parking Chambers Eaton 10 Meritor Rock 23 000 well TWO ist Axle 2 GCW Gross Combination Weight rating can be reduced by vehicle operating applications engine horse power torque axle type model axle ratio and or vehicle tire size Group 726 Volvo Air Suspension Tools Tools 4 W000119
21. affect the driveshaft angles and may cause driveline vibration and or shorten compo nent life Ride height adjustments must be performed in ac cordance with all service manual procedures Group 726 Volvo Air Suspension Volvo Air Suspension Components Spring Bracket The Volvo Air Suspension bracket is a ductile iron casting and includes an internal alignment guide to help center the Z spring within the bracket during initial assembly Wear Plate The wear plate pad is constructed of the same material Ultra High Molecular Weight Polyethylene as earlier wear plates This material provides an extremely smooth surface for the spring to contact and virtually eliminates the noise associated with the metal to metal contact of other suspension designs The Volvo Air Suspension wear plate mounts with a single fastener into a pocket between the vertical legs of the spring bracket Note Wear plates pads must be replaced in pairs left and right to avoid excessive stress on the suspension Z Spring The Z spring has been improved to provide a larger clamping surface an improved alignment with mating components and increased clearance to the lower shock mounting bracket Radius Spring The radius spring is crucial to the vehicle s alignment The radius spring has an improved bushing for increased component durability The Volvo Air Suspension spring uses a locating pin that precisely locates the radius spring for an improved
22. age 26 44 60 10 Nm 44 7 ft lb M20 500 75 Nm 369 55 ft lb M22 575 50 Nm 424 37 ft lb Service Procedures Shock Absorber Removal and Installation Removal W7000744 Remove lower shock mounting bolt Note Follow the Guidelines for Working on the Volvo Air Suspension page 19 2 Remove upper shock mounting bolt and remove shock Installation 3 Install shock and bushings Torque 60 10 Nm bolts to 60 10 Nm 44 7 ft lb 44 7 ft lb Note When replacing shocks use only Volvo approved components shocks and bushings Group 726 Volvo Air Suspension Rear Axle Top Plate Bottom Plate Removal and Installation Removal 4 Chock front wheels on vehicle Note Follow the Guidelines for Working on the Volvo Air Suspension page 19 AN DANGER Personal injury hazard Never work under the vehicle unless the front wheels are securely chocked Failure to chock the wheels can result in the vehicle rolling which can cause serious injury or death to anyone un der or near the vehicle Service Procedures W7000752 Support the nose of the axle with an adeguate jack AN DANGER Failure to properly support the nose of the axle may result in the axle rolling forward Personal injury hazard Never work under or around a raised vehicle unless it is securely supported on jack stands of adequate rating Failure to use ade quate jack stands can resu
23. axle or axles to be worked on 34 Service Procedures W7000763 W7000752 Jack up vehicle and place jack stands under axle s being worked on While lowering vehicle onto jack stands sup port the nose of the axle with a bottle jack AN DANGER Failure to properly support the nose of the axle may result in the axle rolling forward Personal injury hazard Never work under or around a raised vehicle unless it is securely supported on jack stands of adequate rating Failure to use ade quate jack stands can result in the vehicle falling and or rolling which can cause serious injury or death to anyone under the vehicle Group 726 Volvo Air Suspension o W7000715 Remove nuts from U bolts then re move bottom plate U bolts and top clip plate Leave lower shock bracket attached to shock absorber but move bracket clear of work area 6 Remove bolts from crossbeam pedestal plate 7 Remove Z spring Service Procedures Installation 8 Install Z spring into place 9 Install bolts to crossbeam Leave loose do not torque at this time 10 Install top clip plate U bolts and bot tom plate Reposition lower shock bracket Snug up U bolt nuts but do not torgue at this time 11 Raise vehicle and remove jack stands supporting the axle s 12 Install wheels and tires Torque wheel 645 35 Nm and tire nuts to 645 35 Nm 475 475 25 ft Ib 25 ft lb 13 Ra
24. certain that axle seats are properly aligned with the Z spring and radius spring Snug up bolts but do not torque at this time 8 Loosen but do not remove the bolts for the crossbeam pedestal plate to Z spring mounting 9 Make sure the rear suspension is ap proximately at normal ride height air springs inflated 10 Support the frame with jack stands maintaining the approximate normal ride height Deflate the air springs to relieve pressure off the Z spring 11 Center the Z spring within the spring hanger frame bracket Note It may be necessary to tem porarily position a shim between the left side of the spring and the leg of the spring hanger frame bracket to keep the Z spring centered during the U bolt nut torque procedure 12 Torque U bolt nuts to 500 75 Nm M20 369 55 ft Ib for M20 or to 575 50 500 75 Nm Nm 424 37 ft Ib for M22 369 55 ft lb M22 Note To ensure proper refer to 575 50 Nm U bolt Torque Procedure page 26 424 37 ft lb 13 Torque nuts for crossbeam mounting bolts to 105 20 Nm 77 15 ft lb 105 20 Nm 77 15 ft lb 14 Raise the vehicle and remove jack stands supporting frame rails 15 Crank the truck to build air pressure to raise the air Suspension Note Vehicle realignment may be re quired See Guidelines for Working on the Volvo Air Suspension page 19 37 Group 726 Volvo Air Suspension Torque Rod and Frame
25. eft hand and right hand versions Torque Rod The torque rod is located on top of the axle housing lt is positioned between the frame rail mounted bracket and the axle housing mounted bracket It helps maintain lat eral alignment of the rear axle or axles for the suspension W7000696 Design and Function W7000722 13 Group 726 Volvo Air Suspension Design and Function Pneumatic Switch Panel The pneumatic switch panel can have as many as four optional equipment switches They regulate air flow di rectly to the equipment including Differential Lock Wheel and Interaxle Air Suspension Level Fifth Wheel Slide W7000714 Terminal po 16 P gt Interaxle To Cluster 12V Supply Ground 12V Illumi DLO Telltale Lamp nation Control Fifth Wheel To Cluster Not Used Ground 12V Illumi Slide Telltale Lamp nation Control Rest Suspension To Cluster Not Used Ground 12V Illumi ae Dump Telltale Lamp nation Control Interwheel Not Used Ground 12V Illumi DLO nation Control 14 Group 726 Volvo Air Suspension Design and Function Dump Switch Operation To dump air from the system push the switch to the position labeled lower To fill the system push the switch to the position labeled ride Note Lower the suspension when disconnecting the trailer SUPPLY FOR DASH SYSTEMS AIR SUSPENSION DUMP SUP sup R E EM S N 2 y VE T
26. ent J38460 A J38460 25 Group 726 Volvo Air Suspension Air Suspension Ride Height Check Calculation W7000741 Leveling valve Ride height Axle center line Crossbeam BON Before you can accurately calculate the ride height prepare the vehicle us ing these steps e Measurements must be per formed on an unloaded vehicle e Park the vehicle on a level sur face e The steer and rear drive axle tires must be at normal operating pres sure e Free and center all suspension joints by slowly moving the vehicle back and forth twice without using the brake When coming to a complete stop make sure the brakes parking and service are released e Front wheels must be pointed straight ahead 2 Chock the front wheels on the vehicle AN DANGER Personal injury hazard Never work under the vehicle unless the front wheels are securely chocked Failure to chock the wheels can result in the vehicle rolling which can cause serious injury or death to anyone un der or near the vehicle Service Procedures 3 Dump release the suspension air see Dump Switch Operation page 15 AN DANGER Stay clear when suspension air is released Chassis may drop quickly and can cause serious injury or death to anyone under the vehicle Start the engine and fill the suspen sion with air Turn off the engine W7000755 The ride height is the distance from the axle centerline to the bottom of the f
27. er to Volvo Air Suspension Calcula tion Form page 51 Service Procedures ANGLE A ANGLE B ANGLE C FWD AXLE INTERAXLE REAR AXLE PINION SHAFT ANGLE PINION RIDE HEIGHT ANGLE D ANGLE E FWD AXLE JOINT REAR AXLE JOINT WORKING ANGLE WORKING ANGLE W7000742 W7000253 Measure the rear axle angle C using the recommended tooling Record the measurement for calculation refer to Volvo Air Suspension Calculation Form page 51 Note Wipe surface clean of dirt and debris before taking measurement 6 Calculate C B E The rear axle angle minus the inter axle angle will give the value E Record the Measurement for calcula tion refer to Volvo Air Suspension Calculation Form page 51 23 Group 726 Volvo Air Suspension 7 Calculate D E F Record the measurement for calcula tion refer to Volvo Air Suspension Calculation Form page 51 Compare the value of angle F with the following guidelines If F is less than 1 5 lower the ride height If F is between 1 5 and 1 5 no adjustment is necessary If F is greater than 1 5 raise the ride height For procedures on lowering or raising ride height refer to Volvo Air Suspen sion Ride Height Adjustment page 28 8 Proceed to Forward Axle Pinion An gle to Frame Check page 25 24 Service Procedures Group 726 Volvo Air Suspension Forward Axle Pinion Angle to Frame Check
28. fit with the mating Z spring and axle seat Precisely locating the radius spring helps to improve the vehicles overall axle alignment 10 Design and Function W7000695 W7000739 W7000219 W7000761 Group 726 Volvo Air Suspension Crossbeam The crossbeam pedestal plate has been greatly refined to improve strength while reducing weight The Volvo Air Suspension crossbeam uses only four mounting bolts two on each end for easy installation of the Z spring Axle Seat The axle seat defines the axle pinion inclination It has been refined to eliminate the extra spacers necessary in earlier designs By eliminating the spacers the Volvo Air Suspension axle seat forms a strong secure joint be tween the radius spring and the axle Bottom Plate The bottom axle plate is found underneath the axle housing and is held in place by U bolts It helps main tain axle alignment with the springs in the suspension and prevents movement of the axle It can also be help ful in keeping U bolts properly aligned and secured Top Plate The top plate upper clip is located at the top of the Z spring and is clamped down by the U bolts It is helpful in maintaining alignment of the U bolts to secure and align the Z spring radius spring and axle seats The top plate also helps maintain a secure surface for U bolts when torqued Design and Function W7000704 W7000727 Axle seat ZN W7000721 Bottom plate W70
29. for Working on the Volvo Air Suspension page 19 36 Service Procedures Radius Spring Replacement Removal W7000752 Chock front wheels on vehicle Jack up vehicle and place jack stands un der axle s being worked on Lower vehicle onto jack stands to support the nose of the axle AN DANGER Failure to properly support the nose of the axle may result in the axle rolling forward Personal injury hazard Never work under or around a raised vehicle unless it is securely supported on jack stands of adequate rating Failure to use ade quate jack stands can result in the vehicle falling and or rolling which can cause serious injury or death to anyone under the vehicle 2 Remove nuts from U bolts on axle to be worked on Note Follow the Guidelines for Working on the Volvo Air Suspension page 19 Group 726 Volvo Air Suspension W7000725 Raise vehicle from under the rear of the Z spring at the crossbeam pedestal plate just enough to sepa rate the Z spring from the radius spring W7000720 Remove the two 2 bolts from the lower part of the spring anchor then remove the radius spring Installation 5 Install radius spring into place and in stall the two 2 bolts Torque to 275 45 Nm 203 33 ft Ib 275 45 Nm 203 33 ft lb 6 Lower vehicle making certain that Z spring and radius spring are properly aligned Service Procedures 7 Install U bolt nuts making
30. g hanger bolts to 320 50 Nm 236 37 ft lb Note Use only approved fasteners 12 Install bolts for radius spring Torque 275 45 Nm radius spring bolts to 275 45 Nm 203 33 ft lb 203 33 ft lb 13 Install retaining pin and isolator spring roller in spring hanger frame bracket under Z spring 14 Raise the vehicle and remove jack stands supporting the frame rails Lower the vehicle to the ground 15 Crank the truck to build air pressure to raise the air suspension 16 Ride height and pinion angle may re quire adjustment See Volvo Air Suspension Ride Height and Driveline Angle Check Calculation and Adjust ment page 20 Note Vehicle wheel realignment may be required See Guidelines for Working on the Volvo Air Suspension page 19 Group 726 Volvo Air Suspension Wear Plate Pad Replacement Removal 1 W7000720 Remove the retaining pin and isolator spring roller from spring hanger frame bracket located under hook end of Z spring Note Follow the Guidelines for Working on the Volvo Air Suspension page 19 Note It is strongly recommended that the wear plates pads be replaced in pairs left and right side on the same axle 2 Chock front wheels on vehicle Note Follow the Guidelines for Working on the Volvo Air Suspension page 19 AN DANGER Personal injury hazard Never work under the vehicle unless the front wheels are securely
31. ide of truck and deflate air bags to relieve pressure off of the Z spring 3 Remove the nuts and bolts from the radius spring 4 Remove nuts from the bolts on the spring hanger Note These may be Huck style fas teners requiring additional effort for removal Heating the suspension components and frame rail may weaken them Hot surfaces can also cause seri ous burns 5 Raise the rear of the truck to relieve pressure from the spring hanger bolts 39 Group 726 Volvo Air Suspension W7000720 Remove spring hanger bolts in front and behind the bracket 7 Remove hanger 8 Remove the split pin and retaining pin holding the wear plate pad into the spring hanger frame bracket Re move the wear plate Note We recommend replacing wear plates pads They should be re placed in pairs left and right on the same axle See Wear Plate Pad Replacement page 41 Installation 9 Install the wear plate pad add retain ing pin and replacement split pin in the spring hanger frame bracket Note New plates pads should be in stalled They should be replaced in pairs left and right on the same axle See Wear Plate Pad Replacement page 41 10 Work the spring hanger bracket back onto the Z spring 40 Service Procedures 11 Install all bolts to reattach the spring 320 50 Nm hanger and any other bolts that were 236 37 ft lb removed to get to spring hanger Torque sprin
32. ise vehicle and temporarily remove remaining jack stands supporting the frame rails Lower the vehicle to the ground 14 Crank the vehicle to build air pressure to raise the air suspension 15 Reinstall the isolator spring roller with retaining pin and split pin 16 Support the frame with jack stands maintaining the approximate normal ride height Deflate the air springs to relieve pressure off the Z spring 17 Center the Z spring within the spring hanger frame bracket Note lt may be necessary to tem porarily position a shim between the left side of the spring and the leg of the spring hanger frame bracket to keep the Z spring centered during the U bolt nut torque procedure 35 Group 726 Volvo Air Suspension 18 Torque U bolt nuts to 500 75 Nm M20 369 55 ft lb for M20 or to 575 50 500 75 Nm Nm 424 37 ft Ib for M22 369 55 ft lb M22 Note To ensure proper torque refer 575 50 Nm to U bolt Torque Procedure page 26 424 37 ft lb 19 Torque nuts for crossbeam mounting bolts to 105 20 Nm 77 15 ft Ib 105 20 Nm 77 15 ft lb 20 Raise the vehicle and remove jack stands supporting frame rails 21 Crank the truck to build air pressure to raise the air suspension Perform the procedures for Volvo Air Suspension Ride Height and Driveline Angle Check Calculation and Adjustment page 20 Note Vehicle realignment may be re quired See Guidelines
33. lation _ 21 Interaxle U joint Angle Cancellation Check Calculation 22 Forward Axle Pinion Angle to Frame Check o coooocccncccccnccccnncconanonoss 24 LEDO TORQUE FOCUS siciliana 25 Method 1 preferred iii ia 25 a e E as E A a ws 25 Volvo Air Suspension Ride Height Adjustment aaa 26 Volvo Air Suspension Component Replacement aaa 28 Leveling Valve Replacement rrrrnnnnnnnnnnnvrnnnnnnnnnnnnnnvnvnnnnrnnnnnnnnnnnnnsene 28 Link Foa Pre ete 4 29 Crossbeam Pedestal Plate Replacement cccccessseeeeeeeeeeeeeens 31 ZO HEDASEMENE psc iaa 32 Radius Spring Replacement cccccccccsssseeceeceeeeseeceeseueeseeeeessaaeeeess 34 Torque Rod and Frame Bracket Replacement aaa aaa 36 Spring Hanger Frame Bracket Replacement kaka 37 Wear Plate Pad Replacement ccccccccsssseeeeeeeeeeeeeeeeesaeeeeeseaanaees 38 Upper Shock Absorber Bracket Removal and Installation 40 Lower Shock Absorber Bracket Removal and Installation 40 Shock Absorber Removal and Installation encinas Rear Axle Top Plate Bottom Plate Removal and installation eye Air Spring Removal and Installation alta 44 Pete STA FARTEN ani TO ARMA EE EE gt NN P PPP S gt System lia EN E aso sia POR is dai OME F Volvo Air Su M ini 47 Volvo Air Suspension Ride Height a Driveline Angle Check Ds FN Ge JE ae Volvo Air Susp
34. lt in the vehicle falling and or rolling which can cause serious injury or death to anyone under the vehicle 3 Remove nuts from the U bolts then remove the bottom plate and U bolts Leave lower shock bracket attached to shock absorber but position bracket clear of the work area 45 Group 726 Volvo Air Suspension W7000747 Remove the top plate Installation 5 Install the top plate Note Make sure the alignment pin on the bottom of the top plate is engaged into the pocket on the top surface of the Z spring 6 Install the U bolts Note The longer U bolt is positioned to the rear side of the axle housing 7 Install the bottom plate Note Install with the arrow located on the bottom of the plate pointing to ward the front of the truck 8 Reposition the lower shock bracket on the U bolt 9 Snug up the U bolt nuts but do not torque 46 Service Procedures 10 Loosen the mounting bolts for the crossbeam pedestal plate to the Z spring 11 Remove the jack stands and lower the vehicle to the ground 12 Crank the truck to build air pressure to raise the air suspension 13 Support the frame maintaining the ap proximate normal ride height Deflate the air springs to relieve pressure off of the Z springs 14 Center the Z spring within the spring hanger frame bracket Note It may be necessary to tem porarily position a shim between the left side of the spring
35. n clamp at the lower end of the link rod 29 Group 726 Volvo Air Suspension Volvo Air Suspension Compo nent Replacement Note Before replacing any component or performing any other work on the Volvo Air Suspension be sure to read Guidelines for Working on the Volvo Air Suspension page 19 Leveling Valve Replacement Do not try to adjust the leveling valve Do not take the leveling valve apart Do not lengthen or shorten the handle on the valve Removal 4 Chock the front wheels on vehicle and release the parking brakes AN DANGER Personal injury hazard Never work under the vehicle unless the front wheels are securely chocked Failure to chock the wheels can result in the vehicle rolling which can cause serious injury or death to anyone un der or near the vehicle 2 Dump release the suspension air see Dump Switch Operation page 15 AN DANGER Stay clear when suspension air is released Chassis may drop quickly and can cause serious injury or death to anyone under the vehicle 3 Remove the rod from the leveling valve arm 30 Service Procedures W7000709 Remove the bolts from the frame hold ing the valve mounting bracket in place 5 Note the air line positions and orienta tion to the fittings in the valve Disconnect the air lines and remove the valve 6 Swap fittings or position new fittings to the replacement valve 7 Swap bracket from former valve
36. ncorrect Overloaded vehicle Defective air spring Defective manifold Defective leveling valve Air leak or loose line Defective pressure regulator Defective dump switch Troubleshooting i N 18 Group 726 Volvo Air Suspension Service Procedures Service Procedures Ride height has a direct relationship with driveline pinion angles It is critical to main tain all ride height specifications as recommended by Volvo Trucks North America Interaxle cancellation equal forward and rear interaxle U joint angles is the key to re duced driveline vibrations and increased component life Volvo Air Suspension Ride Height and Driveline Angle Check Calculation and Adjustment page 20 describes how to achieve interaxle cancellation by maintaining the proper ride height and pinion angles Guidelines for Working on the 3 When lifting the chassis to perform any Volvo Air Suspension procedure always support the chassis To ensure personal safety and to help avoid accidental with adeguate jack stands before be damage to suspension components follow these guide ginning work on the air suspension lines any time work is performed on the Volvo Air l Sus Note Never jack directly under the pension crossbeam The crossbeam is not de 1 signed to support vehicle weight Chock the front wheels on vehicle and release the parking brakes AN DANGER Personal injury hazard Never work under or around a raised vehicle unless it is
37. nuts that hold the air bags to the crossbeam pedestal plate Push the air springs out of the crossbeam and forward W7000707 Remove the nuts and bolts that hold the crossbeam to the Z springs and remove the crossbeam Service Procedures Installation 4 Install the crossbeam to the Z spring with the nuts and bolts Torque the bolts to 105 20 Nm 77 15 ft Ib 105 20 Nm 77 15 ft lb 5 Install the air springs back onto the crossbeam and torque the nuts to 50 10 Nm 37 7 5 ft Ib 50 10 Nm 37 7 5 ft lb Over torque will damage the air spring 6 When completed jack the rear of the truck up remove the jack stands and lower the vehicle Crank the truck to build air pressure to raise the air sus pension 33 Group 726 Volvo Air Suspension Z Spring Replacement Removal 4 Remove isolator spring roller from spring hanger frame bracket This is located under hook end of Z spring W7000718 Chock wheels on vehicle Jack up ve hicle and place jack stands under frame rails Secure jack stands and lower vehicle Note Follow the Guidelines for Working on the Volvo Air Suspension page 19 N DANGER Personal injury hazard Never work under the vehicle unless the front wheels are securely chocked Failure to chock the wheels can result in the vehicle rolling which can cause serious injury or death to anyone un der the vehicle 3 Remove wheels and tires on
38. on System Check Volvo Air Suspension Ride Height and Driveline Angle Check Flow Diagram START Check suspension Adjust suspension ride height 1 ride height 3 Is ride height Check replace within specified No faulty suspension tolerances components 4 Yes Check interaxle U joint cancellation angle 2 Is the cancellation within No No specified tolerances Yes Check forward axle pinion angle to frame 5 SMB a Is this the Perform a an u No THIRD attempted Yes U bolt torque doleraness adjustment procedure 6 Yes CHECK COMPLETE W7000749 1 See Volvo Air Suspension Ride Height and Driveline Angle Check Calculation and Adjustment page 20 2 See Interaxle U joint Angle Cancellation Check Calculation page 22 3 See Volvo Air Suspension Ride Height Adjustment page 28 4 See Volvo Air Suspension Component Replacement page 30 5 See Forward Axle Pinion Angle to Frame Check page 25 6 See U bolt Torque Procedure page 26 92 Group 726 Volvo Air Suspension System Check Volvo Air Suspension Calculation Form Use this form to record the measurements for calculating ride height and checking pin ion angles all angle measures are in degrees ANGLE A ANGLE B ANGLE C FWD AXLE INTERAXLE REAR AXLE PINION SHAFT ANGLE PINION ANGLE P RELATIVE TO ia rem SL Az ANGLE D ANGLE E FWD AXLE JOINT REAR AXLE JOINT WORKING ANGLE WORKING A
39. plete system pressure before disconnecting hoses or components may result in them separating violently and causing serious bodily injury Drain air pressure from vehicle sys tem Mark each air line to keep correct arrangement W7000706 Disconnect air lines at switch being re J 42189 placed by pushing in on the ring and air line using the air line release tool J 42189 then pulling the air line out i i W3000658 To remove switch insert a no 1 flat tip screwdriver into back of switch at top and bottom to release locking tabs Push switch out of the panel Installation 1 Install new air switch into the panel pushing the switch into the panel until it locks Push back on the switch to make certain it is locked in the panel Group 726 Volvo Air Suspension 2 Connect air lines to the switch making sure they are installed in the correct position Be sure to insert airline to line indicated 3 Connect electrical LED connections on switch and both cigar lighter connec tions 4 Align and install switch panel in dash 5 Install ashtray housing with the 2 0 4 0 1 Nm mounting screws Torque screws to 3 5 1 in Ib 0 4 0 1 Nm 3 5 1 in Ib 6 Place ashtray in housing Service Procedures 49 50 Group 726 Volvo Air Suspension System Check System Check Volvo Air Suspension SSS gt gt 5 a W7000753 51 Group 726 Volvo Air Suspensi
40. rame rail The ride height must be within the following specifications e Low frame outside rail height di mension approx 266 mm 10 5 in 196 216 mm 7 75 8 5 in e High frame outside rail height di mension approx 300 mm 11 75 in 179 199 mm 7 0 7 75 in To accurately measure ride height a Measure from the ground to the bottom of the frame rail 1 b Locate the axle centerline the center hole on the end of the hub works best using a steel rule or an appropriate tool 2 Measure from the ground to the axle cen terline 3 c Calculate the difference be tween 1 and 3 The difference is the ride height 4 d Ride height should fall within specifications for low or high rail chassis see above 21 Group 726 Volvo Air Suspension 5 Record the measurement for calcula tion refer to Volvo Air Suspension Calculation Form page 51 If the measurement is not within the speci fied range it must be corrected before proceeding If the ride height is not in specification check for the following e Excessively worn wear plates pads Note Wear plates pads must be replaced in pairs left and right on same axle see Wear Plate Pad Replacement page 40 e Damaged spring hanger frame bracket e Damaged air spring Z spring and or radius spring e Damaged link rod e Faulty leveling valve Replace the components as neces sary then adjust the suspension ride
41. securely supported on jack DANGER Personal injury hazard Never work under the vehicle stands of adequate rating Failure to use adequate jack stands can result in the vehicle falling which can cause serious injury or death to anyone under the ve hicle unless the front wheels are securely chocked Failure to chock the wheels can result in the vehicle rolling which can cause serious injury or death to anyone un der or near the vehicle 2 Dump release the suspension air AN DANGER Stay clear when suspension air is released Chassis may drop quickly and can cause serious injury or death to anyone under the vehicle 19 Group 726 Volvo Air Suspension 4 To ensure that the U bolts holding the rear suspension to the drive axle re tain their clamp load observe the following practices a Any time you work on the sus pension make sure you loosen both sides of the suspension on an axle at the same time It is difficult to realign all parts with op posite side of the axle restricting motion b Whenever the U bolts are loos ened always support the nose of the axle with an adequate jack AN DANGER Failure to properly support the nose of the axle may result in the axle falling which can cause serious in jury or death to anyone under the vehicle c Whenever the U bolts are loos ened and or the suspension components attached to the axle are being worked on make sure that the locating fea
42. tario L5T 1W8 http www volvotrucks volvo com PV776 TSP27725 1 2000 11 97 Volvo Trucks North America Inc 97
43. tion the ride height may move out of the specified range 6 Adjust the position of the lower rubber mount on the link rod so that the lower mounting stud is aligned with the hole in the crossbeam pedestal plate 7 Reinstall the lower mounting stud of the link rod to the crossbeam Note the position of the washer Torque to 10 1 5 Nm 7 1 ft lb 10 1 5 Nm 7 1 ft lb Note Do not crimp or tighten the clamp at the lower end of the link rod at this time 8 Remove the Allen wrench from the leveling valve Failure to remove the Allen wrench will damage the leveling valve and or link rod Service Procedures 9 Dump release the suspension air see Dump Switch Operation page 15 AN DANGER Stay clear when suspension air is released Chassis may drop quickly possibly causing serious injury to anyone under the vehicle 10 Crank the truck to build up air pres sure to check the ride height see Air Suspension Ride Height Check Calcu lation page 21 The ride height must be within specifications as follows Low frame outside rail height di mension approx 266 mm 10 5 in 196 216 mm 7 75 8 5 in High frame outside rail height di mension approx 300 mm 11 75 in 179 199 mm 7 0 7 75 in 11 Perform the Interaxle U joint Angle Cancellation Check Calculation page 22 and the Forward Axle Pin ion Angle to Frame Check page 25 12 Crimp or tighte
44. tor spring roller re taining pin and a replacement split pin in the spring hanger frame bracket under the Z spring 12 Ride height and axle pinion angle may reguire adjustment See Volvo Air Suspension Ride Height and Driveline Angle Check Calculation and Adjust ment page 20 42 Service Procedures Upper Shock Absorber Bracket Removal and Installation Removal W7000744 Remove upper shock mounting bolt Remove shock and position out of the work area 2 Remove frame fasteners from upper shock bracket Note These may be Huck style fas teners requiring additional effort for removal Heating the suspension components and frame rail may weaken them Hot surfaces can also cause seri ous burns 3 Remove upper shock bracket Group 726 Volvo Air Suspension Installation 4 Install the shock bracket Torque fas teners to 320 50 Nm 236 37 ft lb 320 50 Nm 236 37 ft lb Note Use only approved fasteners 5 Install shock bushings and upper 60 10 Nm shock mounting bolt Torque bolt to 60 44 7 ft lb 10 Nm 44 7 ft lb Note When replacing shocks use only Volvo approved components shocks and bushings Lower Shock Absorber Bracket Removal and Installation Removal 1 Chock front wheels on vehicle and re move nuts from U bolts on axle to be worked on Note Follow the Guidelines for Working on the Volvo Air Suspension page 19 AN
45. tures on each component is properly engaged so that the components are posi tioned together properly d Make sure that the pin in the ra dius spring has not been pushed out of position If the pin is cor rectly set make sure that the pin in placed in its proper position rel ative to the axle seat and Z spring before clamping it with the U bolts e Always replace both U bolts at a particular axle position The longer of the two U bolts is posi tioned to the rear side of the axle housing 20 Service Procedures f Before torquing the U bolt nuts position the suspension at approx imately the normal ride height and make sure the bolts holding the crossbeam pedestal plate to the Z spring are loosened This will help provide proper alignment for the Z springs g Always snug up the U bolt nuts all over first before torguing using a handheld clicker style torque wrench 5 After work has been performed on the air suspension vehicle realignment may be required Refer to proper ser vice information Volvo Air Suspension Ride Height and Driveline Angle Check Calculation and Ad justment The Volvo Air Suspension is set at the factory Chang ing the ride height will affect the driveshaft angles and may cause driveline vibration and or shorten compo nent life Ride height adjustments must be performed in accordance with all service manual procedures Special tools J 42189 Other special equipm
46. using a permanent crimp style clamp you must first remove the rubber mount from the link rod before installing the clamp 28 Service Procedures W7000746 A Raise B Neutral C Lower Raising ride height Raise the ride height by holding the leveling valve arm upwards until the ride height is within specifications as follows e Low frame outside rail height di mension approx 266 mm 10 5 in 196 216 mm 7 75 8 5 in e High frame outside rail height di mension approx 300 mm 11 75 in 179 199 mm 7 0 7 75 in AN DANGER Use caution when moving the leveling valve arm down This will release the suspension air and the chassis may drop quickly possibly causing serious in jury or death to anyone under the vehicle OR Lowering ride height Lower the ride height by holding the leveling valve arm down until the ride height is within specifications as fol lows e Low frame outside rail height di mension approx 266 mm 10 5 in 196 216 mm 7 75 8 5 in e High frame outside rail height di mension approx 300 mm 11 75 in 179 199 mm 7 0 7 75 in Group 726 Volvo Air Suspension W7000748 Return the leveling valve arm to the neutral position Place the short side of a 5 32 in Allen wrench through the hole 1 on the leveling valve arm and into the valve This locks the arm in the neutral position Note If the leveling valve arm is not kept in the neutral posi
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