05-101.02/ 1 2010SE29 SECTION 05-101.02 GENERAL DESCRIPTION The rear axle is an AV-132 ZF model equipped with a pneumatic disc brakes system. An identification plate is affixed to the right rear side of the axle and contains information to assist you when ordering replacement parts. AXLE REPLACEMENT VEHICLE HOISTING. Follow your internal safety procedure, and use appropriate safety equipment for your protection. See section 18: Hoisting and Towing in this manual regarding lifting and towing procedures before raising or lowering the vehicle. When replacing rear axle and suspension components, they must be replaced with new original parts, or equivalent. The specified torque values must be followed when assembling components. See the manufacturer s manuals for more details regarding the rear axle assembly and accessories. AXLE REMOVAL See Figures 1 and 2. It is not necessary to completely remove the axle from the vehicle, if the maintenance only covers components. 1. Make sure that supports have been placed in the proper locations under the vehicle and raise the vehicle. 2. Disconnect the height adjustment valve linkage on each side of the vehicle. Pull the linkage downward in order to completely empty the air springs of compressed air. See section 08-401 : Kneeling and leveling. For added security, it is important to completely empty the air springs of all air before starting any work on the axle. 3. Remove the split pin and the brake nut from the support rod and detach the rod from the bracket and the stabilizer bar. Stabilizer bar can be disconnected by removing the support. 4. Disconnect the brake line manifold hoses on both sides of the rear structure and move these hoses away from the work area. 5. Disconnect the ABS brake sensor on the connector box in the rear suspension. Remove the attachments that hold the sensor hoses to the structure. 6. Disconnect the drive shaft connection (7). See section 10-500: Drive Shaft in this manual for more details. 7. Remove the bolts (8) and the nuts (9) securing the air springs (10) and the lock plates to the axle. For more information on removal of the air springs, see section 05-001. Air springs and Rear Suspension in this manual. When disconnecting the pneumatic air lines of the suspension system, maintain the lines downward and away from the face, until all the air has been released from the line, to prevent injury. 8. Disconnect the ends of each shock absorber (11) attached to the axle support (12). Separate the shock absorbers from the axle. See section 04-301 Sachs shock absorbers in this manual. 9. Disconnect the ends of each upper radius rod (13) attached on the axle. Disconnect the end of each lower radius rod (14) that is attached to the structure of the vehicle. See section 04-701: Radius Rods, in this manual for more details. At the time of removal of the axle, take note of the location of each radius rod shim, in order to determine the proper alignment following installation.
2010SE29 2 /05-101.02 1. STABILIZER BAR 2. SPLIT PIN 3. BRAKE NUT 4 RADIUS ROD 5. BRACKET 6. BOLT 7. NORD-LOCK WASHER 2, 3 5 4 6,7 135 ±10 N M (100 ±7 LB-PI) 1 Figure 1 - Stabilizer bar installation 10. Lower the axle until the air springs are completely clear of the axle. Prior to final removal of the axle from the vehicle, make sure that nothing interferes with the axle s intended line of movement. AXLE INSTALLATION For the installation of the axle, raise the vehicle and follow the REMOVAL procedure, but in the reverse order. Always apply the following safety recommandations: 1. Clean all mating surfaces, all linkages and all supports on the structure and on the axle. Put anti-corrosive lubricant (Never Seeze) on all threaded rods and all bolts before tightening, in order to ensure an easier disassembly in future. 2. For torque values of the axle components, refer to the following sections in this manual. 04-301 : Sachs shock absorbers 05-001: Air springs & rear suspension 04-701 : Radius rods 10-500 : Drive shaft 3. Prior to installation, verify the thickness of the air spring lock plates (15).The air spring lock plates on the street side are thicker than the air spring lock plates on the curb side. 4. The radius rods (13 and 14) and the air springs (10), although connected, are only tightened once the installation of the axle has been completed, but prior to the installation of the driveshaft (7) and the stabilizer bar (1). CAUTION : Radius rod bolts must be tightened following a specific order. See section 04-701: Radius Rods in this manual for more details. 5. When re-installing the radius rods, make sure to put the same number of shims in order to maintain the proper alignement. At all times, it is preferable to follow the alignment procedure in section 04-000: ZF Axle alignment, following axle installation. 6. Make sure that all brake hoses are properly connected to the brake cylinder. See the pneumatic system schematic for more informations. 7. Following installation of the axle, it is necessary to ensure that hoses, piping, sensors, etc. are properly secured and do not interfere with moving parts of the axle. 8. Verify all pneumatic components, in order to ensure that there are no leaks. 9. Test the brakes in a safe place, before performing a road test, in order to ensure the proper integrity of all components. NOTE : During the road test, if the axle floats or vibrates, verify the caster adjustment, the balancing of the wheels and tires and the condition of the shock absorbers.
05-101.02/ 3 2010SE29 17 10 6 11 6. ABS SENSOR 7. DRIVE SHAFT CONNECTION 8. BOLT 9. BRAKE NUT 10. AIR SPRING ASSEMBLY 11. SHOCK ABSORBERS 12. SPRING BRACKET 13. UPPER RADIUS ROD 14 LOWER RADIUS ROD 15. LOCK PLATE 16. HEIGHT ADJUSTMENT PLATE 17. BRAKE CYLINDER 13 15 14 16 8,9 7 12 Figure 2 - Rear axle assembly
2010SE29 4 /05-101.02 PRELIMINARY ASSEMBLY OF A NEW AXLE 1. Insert the two elbows on each of the two brake cylinders (17) and ensure that proper torque values are used, in order to avoid possible air leaks. 2. Place the covering over the brake air duct hoses on both sides. 3. Install both lower radius rods (14) on the central part of the axle with the proper bolts and washers and tighten in the recommended order. See section 04-701: radius Rods for the recommended tightening order and proper torque values. 4 Install the two brackets (5) of the stabilizer bar (1) and secure with bolts and self-locking washers (Nord-Lock). Tighten to the proper torque values. See Figure1. The orientation of Nord-Lock washers and the torque application method used on hardware installed with these washers are crucial. See section 99: general practices for more information. 5. Install the two support rods (4) for the stabilizer bar (1) on the two brackets (5) and tighten with the brake nut (3) and the split pin (2). 6. Install each of the two height adjustment plates (16) with bolt (8) and washer (9) and tighten. AXLE MAINTENANCE INSPECTION The following inspections must be performed on a regular basis determined by the operating conditions. Components of the axle must be carefully inspected before installation, Check for worn or damage parts and replace them if necessary. Immediate replacement of of these parts can prevent premature wear of the axle. NOTE : It is possible to replace components without removing them from the vehicle. Although a complete removal is recommended for better access to the components, it is acceptable to perform maintenance on an already installed part. 1. It is strongly advised to inspect the axle using the magnaflux method, in order to reveal any damage, or cracks, not visible to the naked eye, on precision surfaces for all axle components, with the exception of ball-bearings or rollers. 2. Slowly turn each bearing and examine carefully for roughness, damage, defects or wear. Replace the bearing if the cage is damaged or shows any of these conditions. 3. Examine the crown, the drive flange and the differential gear for tooth damage, worn areas and distortion. If the crown or the drive pinion are worn or damaged, both must be replaced as a unit. Never replace the crown or drive flange separately. Check the differential pinion for excessive wear and adjustment of the spider. 4. Examine the end of the axle shaft serration for twisted flutings or fissures, a twisted shaft or a damaged coupling. Install a new shaft if any of these conditions exist. 5. If inspection reveals deflection or bending, the housing must be replaced. It is not recommended to straighten the axle. Under no circumstances is heat to be applied to the axle housing. 6. Inspect the pneumatic suspension, the air springs and the related components If the air springs are damaged they must be replaced. See section 05-001 : Air springs and rear suspension in this manual for more information. 7. Inspect the support rods (13 et 14) for wear or damage and replace if necessary. See section 04 701 : Radius rods in this manual for more information 8 Inpect bolts, assemblies and axle installation. Make sure that torques values are identical to the specifications. 9. If abnormal wear of the tires is detected, verify the geometry of the axle as per procedure available in section 04-000 ZF axle alignment in this manual. CLEANING OF PARTS Immerse all parts in an appropriate cleaning liquid and clean the parts thoroughly. Use a soft silk brush to remove the old lubricant. Remove any particles of gaskets, seals, etc., that can adhere to the mating surfaces of the differential housing, the differential flange, the hub and the wheel shaft flanges. Clean the lubricant channels in the axis of the differential flange and the differential flange. Clean the vent casing. Thoroughly clean the inside of the differential housing. Soak the differential and the drive pinion bearing in clean kerosene, or diesel fuel, or a cleaning solvent. Do not use gasoline and never place the bearings in a hot solution. CAUTION: Serious injuries can result from improper or careless use of solvents, hot solutions, or alcaline solutions when cleaning components. Always refer to the manufacturer s manual to prevent accidents. Never use gazoline to clean parts, this could cause explosions.
05-101.02/ 5 2010SE29 CLEANING OF BEARINGS NOTE : Adequate cleaning of the bearings is very important. The bearings must always be cleaned separately from other axle parts. The bearings must be cleaned as follows : 1. Once all old lubricant has been removed, hold the bearing raceway so as to prevent the bearing from turning, then brush the bearing with a soft silk brush until all dust and dirt have been removed. 2. Rinse the bearing in a clean bath, then blow dry compressed air through it. Make sure that the flow of air is free from moisture. 3. Inspect the bearing as described previously in this section. If the bearing is acceptable following inspection, dip it in a bath of differential lubricant and wrap it in a dry cloth or clean dry paper, ready for assembly on the axle. POST INSPECTION PROCEDURES After the inspection of the brake system is completed, it is important to verify the lubrication of the braking system and to ensure that it is in good working order. Following each brake system overhaul, conduct a road test and inspect each component of the installation. OIL CHANGE AND LUBRICATION See section 19 : Fluids et lubricants and the ZF manuals for oil change and lubrication intervals. BRAKES INSPECTION AND REPLACEMENT OF BRAKE COMPONENTS For inspection procedure of the pads, discs and other components of the brake system, refer to the brake manufacturer s manual. When wear of the brake pads exceeds the acceptable limits, replace the pads in accordance with the procedure available in the manufacturer s manual. See Figure 4 for quick reference to the brake manufacturer recommended wear limits. A = 45 MM, NEW ORIGINAL DISC. B = 37 MM, MINIMUM DISC THICKNESS; REPLACE THE DISC. C = 30 MM, TOTAL THICKNESS OF A NEW ORIGINAL BRAKE PAD. D = 9 MM, THICKNESS OF THE BRAKE LINING SUPPORT. E = 2 MM, MINIMUM THICKNESS OF THE FRICTION MATERIAL; REPLACE THE PAD. F = 11 MM, MINIMUM THICKNESS OF THE PAD; REPLACE THE PAD. Figure 4 - Quick Reference On Pads And Disc Brakes Status
2010SE29 6 /05-101.02 BLANK PAGE