Tools Required

1. Raise the vehicle. Support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
2. Place a drain pan or suitable container under the rear axle housing.



3. Remove the rear axle housing oil level/filler plug (1) from the rear axle housing.
4. Remove the rear axle housing drain plug (2) from the rear axle housing.
5. Drain the rear axle housing.
6. Remove the rear tire and wheel assemblies. Refer to Wheel Removal in Tires and Wheels.
7. Remove the rear brake drums from the rear axle. Refer to Brake Drum Replacement in Drum Brakes.
8. Remove both rear axle shafts from the rear axle housing. Refer to Axle Shaft Replacement in this section.



9. Remove both of the rear axle shaft inner oil seals (1) from the rear axle housing with the J 26941 and the J 23907 .
10. Remove both of the rear axle shaft inner oil seal protectors from the rear axle housing.

Important: To ensure rear propeller shaft balance, an index mark (reference mark) (1) must be placed on the differential pinion flange (3) and the rear propeller shaft flange so that the rear propeller shaft can be installed in the same position from which it was removed. If this procedure is not followed, a driveline imbalance may result causing vibration, premature component wear or other undesirable characteristics.




11. Remove the following from the vehicle:

•	The four bolts

•	The four nuts

•	The rear propeller shaft (2)




12. Loosen both rear control arm (2) through bolts and nuts (1).
13. Remove the drain pan from under the rear axle housing.
14. Lower the vehicle so that the rear axle housing may be supported with a hydraulic jack.



15. Support the rear axle housing (1) with a suitable hydraulic floor jack (2).
16. If the vehicle is LSPV equipped, remove the two bolts securing the Load Sensing Proportioning Valve (LSPV) spring bracket to the upper control arm.



17. Remove the four bolts from the rear control arm ball joint boss (3). Separate the rear control arm ball joint boss from the differential carrier.



18. If vehicle equipped, remove the two bolts and the rear wheel speed sensor cover (1) from the differential carrier (2).



19. If vehicle equipped, remove the electrical connector (1) from the rear wheel speed sensor.



20. Remove the eight nuts and the differential carrier (2) from the rear axle housing (1).



21. Remove the rear brake fluid pipes (1) from the rear wheel cylinders.
22. Separate both of the brake backing plates (2) from the rear axle housing (3).



23. Remove one E-clip (1) and the brake fluid hose from the rear axle housing brake fluid hose bracket (3).



24. Remove the five screws from the brake fluid pipe clamps (1).



25. Separate the brake fluid pipes (2) from the rear axle housing.



26. Remove one clamp (1) and the rear axle housing breather hose (2) from the rear axle housing (3).



27. Remove the two nuts and the two washers, one from each side, from the lower rear shock absorber through bolts (3) at the rear axle housing.
28. Remove the two nuts and the two washers, one from each side, from the rear trailing rods (5) at the rear axle housing.

Caution: To prevent personal injury and/or component damage, use the proper tools to support the lower control arm when removing the coil spring. The coil spring is under extreme pressure and can become a projectile should the spring separate from the lower control arm before all of the tension is relieved.

29. Slowly lower the hydraulic floor jack until the coil spring pressure is relieved.
30. Remove the two through bolts (one from each side) (3) and separate the rear shock (2) from the rear axle housing.
31. Remove the two through bolts (one from each side) (6) and the separate rear trailing rods (5) from the rear axle housing.
32. Remove the rear coil springs from the rear axle housing.
33. Remove the rear axle housing from under the vehicle.
34. Clean the rear axle housing thoroughly with solvent and dry.
35. Inspect the rear axle housing mating surfaces and flanges for cracks or other damage.
36. Replace the rear axle housing mating surfaces and flanges as necessary.

1. Position the rear axle housing under the vehicle with the hydraulic floor jack.

Caution: To prevent personal injury and/or component damage, make sure the coil spring is properly seated and use the proper tools to install the lower control arm to the vehicle. The coil spring is under extreme pressure and can become a projectile should the spring separate from the lower control arm before the lower control arm is secured to the vehicle.





Important: When installing the rear coil springs in their spring seats, make sure that the spring end with the stepped portion (landing) is aligned with the stepped portion of the rear axle housing.

2. Install the two rear coil springs (1) to their proper positions on the rear axle housing spring seats (4).
3. Install both of the trailing rods to the rear axle housing (2) and insert two through bolts (one in each side).
4. Install both of the rear shock absorbers to the rear axle housing and insert two through bolts (one in each side).
5. Slowly raise the rear axle housing with a hydraulic floor jack until the rear coil springs (1) are positioned in the upper spring seats.



6. Install two nuts and washers (one on each side) to the rear trailing rod through bolts (4) to the rear axle housing.

Tighten
Tighten the rear trailing rod through bolts and nuts to 90 N·m (66 lb ft).

7. Install two nuts and washers (one on each side) to lower the rear shock absorber through bolts (3) at the rear axle housing.

Tighten
Tighten the lower rear shock absorber through bolt and nuts to 85 N·m (63 lb ft).




8. Install the rear axle breather hose (2) the rear axle housing (3). Secure the breather hose with one clamp (1).



9. Install the brake fluid pipes (2) to the rear axle housing.



10. Install five brake pipe clamps (1) to the rear axle housing.
11. Secure the brake fluid pipes and the clamps with five screws.



12. Install the brake hose to the rear axle housing brake hose bracket (3). Secure with the E-clip (1).



13. Apply the RTV silicone gasket and sealer GM P/N 12346240, or the equivalent (2), to the rear axle housing brake backing plate flanges (1).



14. Apply RTV silicone gasket and sealer GM P/N 12346240, or equivalent, to the differential carrier mating surface (1) on the rear axle housing (2).




Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

15. Install the differential carrier into the rear axle housing. Secure the differential carrier with eight nuts (1).

Tighten
Tighten the differential carrier nuts to 55 N·m (41 lb ft).




16. If vehicle equipped, install the electrical connector (1) to the rear wheel speed sensor.



17. If vehicle equipped, install the rear wheel speed sensor cover (1) to the differential carrier (2). Secure the cover with two bolts.

Tighten
Tighten the rear wheel speed sensor cover bolts to 15 N·m (11 lb ft).




18. Install the rear control arm ball joint boss (3) to the differential carrier (2). Secure ball joint boss with four bolts.

Tighten

•	Tighten the rear control arm ball joint boss bolts to 50 N·m (37 lb ft).

•	Tighten the rear control arm through bolts and nuts to 90 N·m (66 lb ft).

19. If vehicle equipped, install the LSPV load sensing spring bracket to the upper control arm. Secure the bracket with two bolts.

Tighten
Tighten the load sensing spring bracket bolts to 18 to 25 N·m (13.5 to 20.0 lb ft).

20. Remove the hydraulic floor jack from under the rear axle housing.
21. Raise and suitably support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.




Important: Use the index (reference) marks made in the removal procedure to ensure correct rear propeller shaft installation.

22. Install the rear propeller shaft (2) into the vehicle. Secure with four nuts and bolts.

Tighten
Tighten the rear propeller shaft nuts and bolts to 50 N·m (37 lb ft).

23. Install both of the rear axle shaft inner oil seal protectors into the rear axle housing.



24. Install the new rear axle shaft inner oil seals (1) into the rear axle housing using the J 29039 and the J 8092 .
25. Apply wheel bearing lubricant GM P/N 1051344, or the equivalent, to the new seal lip.
26. Install both rear axle shafts into the rear axle housing. Refer to Axle Shaft Replacement in this section.
27. Install the rear brake drums to the rear axle. Refer to Brake Drum Replacement in Drum Brakes.
28. Bleed the rear brakes . Refer to Hydraulic Brake System Bleeding
29. Install the rear tire and wheel assemblies. Refer to Wheel Installation in Tires and Wheels.
30. Apply GM P/N 12346004, or equivalent, to the threaded portion of the rear axle housing drain plug.



31. Install the rear axle housing drain plug (2) into the rear axle housing.

Tighten
Tighten the rear axle housing drain plug to 25 N·m (18 lb ft).

32. Refill the rear axle housing with approximately 2.2 liters (4.6 pts) of 80W-90 GL5 lubricant GM P/N 12345977, or equivalent. The oil level should be even with the bottom of the rear axle housing oil level/filler plug hole.
33. Install the rear axle housing oil level/filler plug (1) into the rear axle housing.

Tighten
Tighten the rear axle housing oil level/filler plug to 43 N·m (32 lb ft).

34. Lower the vehicle.