Tools Required

1. Raise the vehicle. Refer to Lifting and Jacking the Vehicle .
2. Remove the differential carrier assembly. Refer to Differential Carrier Assembly Replacement .
3. Remove the drive pinion yoke and the oil seal. Refer to Front Differential Drive Pinion Flange/Yoke, Seal, and Dust Deflector Replacement .



4. Install the J 22536 as shown.

Ensure that the J 22536 is firmly seated on the pinion.

5. Drive the pinion out using the J 22536 and a hammer.

Strike the J 22536 slowly. Do not let the pinion fall out of the rear axle housing.




6. Remove the collapsible spacer from the pinion. Discard the spacer.
7. Remove the pinion bearings and the cups. Refer to Drive Pinion Bearings Replacement .
8. Remove the ring gear. Refer to Differential Case Assembly Disassemble .

Important: The mating surface of the ring gear and the differential case must be clean and free of burrs before installing the ring gear.

1. Install the ring gear to the differential case. Refer to Differential Case Assembly Disassemble .
2. Install the new ring gear bolts.

Hand start each bolt to ensure that the ring gear is properly installed to the differential case.

Notice: Refer to Fastener Notice in the Preface section.

3. Tighten the new ring gear bolts alternately and in stages, gradually pulling the ring gear onto the differential case.

Tighten
Tighten the ring gear bolts in sequence to 120 N·m (89 lb ft).

4. Install the drive pinion bearing cups. Refer to Drive Pinion Bearings Replacement .
5. Determine the selective shim thickness for the pinion gear. See Differential Side Bearing Preload Adjustment Procedure below.
6. Install the selective shim onto the pinion.
7. Install the inner pinion bearing onto the pinion. Refer to Drive Pinion Bearings Replacement .



8. Install a new collapsible spacer.
9. Lubricate the pinion bearings with axle lubricant. Refer to Fluid and Lubricant Recommendations .
10. Install the pinion to the axle housing.
11. Install the outer pinion bearing.



12. Install a new pinion oil seal using the J 21128 .
13. Apply sealant, GM P/N 12346004 (Canadian P/N 10953480) or equivalent, to the splines of the pinion yoke.



14. Install the pinion yoke.

Align the marks made during removal.

15. Seat the pinion yoke onto the pinion shaft by tapping it with a soft-faced hammer until a few pinion shaft threads show through the yoke.
16. Install the washer and a new pinion nut.



17. Install the J 8614-01 onto the pinion yoke as shown.

Important: If the rotating torque is exceeded, the pinion will have to be removed and a new collapsible spacer installed.

18. Tighten the pinion nut while holding the J 8614-01 .

Tighten
Tighten the pinion nut until the pinion end play is just taken up. Rotate the pinion while tightening the nut to seat the bearings.




19. Measure the rotating torque of the pinion using an inch-pound torque wrench.

Specification
The rotating torque of the pinion should be 1.0-2.3 N·m (10-20 lb in) for used bearings or 1.7-3.4 N·m (15-30 lb in) for new bearings.

20. If the rotating torque measurement is below 1.0 N·m (10 lb in) for used bearings, or 1.7 N·m (15 lb in) for new bearings, continue to tighten the pinion nut.

Tighten
Tighten the pinion nut, in small increments, as needed, until the torque required in order to rotate the pinion is 1.0-2.3 N·m (10-20 lb in) for used bearings or 1.7-3.4 N·m (15-30 lb in) for new bearings.

21. Once the specified torque is obtained, rotate the pinion several times to ensure the bearings have seated.

Recheck the rotating torque and adjust if necessary.

22. Install the differential carrier assembly. Refer to Differential Carrier Assembly Replacement .
23. Perform a gear tooth contact pattern check on the pinion and the ring gear. Refer to Gear Tooth Contact Pattern Inspection .
24. Lower the vehicle.

Important: 

1. Install the drive pinion, if necessary. Refer to Drive Pinion and Ring Gear Replacement .
2. Measure the rotating torque of the drive pinion using an inch-pound torque wrench.

Specification
The rotating torque of the drive pinion should be 1.7-3.4 N·m (15-30 lb in) for new bearings or 1.1-2.3 N·m(10-20 lb in) for used bearings.

3. Record the measurement.

Important: Before installation of the differential assembly, ensure that the side bearing surfaces in the axle housing are clean and free of burrs. If the original bearings are to be reused, the original bearing cups must also be used.

4. Install the differential assembly with the side bearings and bearing cups into the axle housing.
5. Insert one 4.318 mm (0.170 in) thick service spacer into the left side of the axle housing.
6. Side the differential assembly towards the service spacer in order to hold the spacer in place.
7. Install the J 22779 between the right side differential side bearing cup and the axle housing.

Important: Over-tightening may spread the housing and result in incorrect shim selection.

8. Tighten the knob on the J 22779 until there is moderate drag when the J 22779 is moved.
9. Remove the J 22779 .
10. Remove the service spacer.
11. Using a micrometer, measure the thickness of the J 22779 in 3 locations.
12. Calculate the average of the 3 measurements.

Record the measurement.

13. Using a micrometer, measure the thickness of the service spacer.

Record the measurement.

14. Add the thickness of the service spacer to the average thickness of the J 22779 .

The resulting value is the total service shim thickness without preload for the axle.

15. Insert one 1.016 mm (0.040 in) service shim between the right side differential side bearing cup and the axle housing.
16. Insert one BENT 1.016 mm (0.040 in) service shim between the right side differential side bearing cup and the service shim.
17. Install the J 22779 on the left side of the differential assembly.
18. While rotating the ring gear back and forth, tighten the knob on the J 22779 until there is approximately 0.025-0.051 mm (0.001-0.002 in) of backlash between the ring gear and the drive pinion.
19. Once the amount of backlash is obtained, remove the J 22779 .
20. Remove the differential case with the differential side bearings and the bearing cups.
21. Remove the service shims.
22. Using a micrometer, measure the thickness of the J 22779 in 3 locations.
23. Calculate the average of the 3 measurements.

This value is the left side service shim thickness without preload.

24. Subtract the service shim thickness for the left side of the axle, calculated in step 23, from the total service shim thickness, calculated in step 14.

This value is the service shim thickness for the right side of the axle without preload.

25. In order to initially set the preload of the differential side bearings and the backlash to approximately 0.013-0.023 mm (0.005-0.009 in), take the value determined in step 24 and add 0.0203 mm (0.008 in) service shim thickness to this amount.
26. Assemble the left side shim pack using one 4.318 mm (0.170 in) service spacer and the appropriate amount of selective service shims equaling the thickness determined in step 23.

Measure the service spacer and the service shims separately.

Add the measurements together in order to determine the total shim pack thickness.

27. Assemble the right side shim pack using one 4.318 mm (0.170 in) service spacer and the appropriate amount of selective service shims equaling the thickness determined in step 25.

Measure the service spacer and the service shims separately.

Add the measurements together in order to determine the total shim pack thickness.

28. Install the differential assembly with the differential side bearings and the differential side bearing cups.
29. Install the left side service spacer between the axle housing and the differential assembly.
30. Install the left side selective service shim or shims.

The service shim or shims must be installed between the service spacer and the differential side bearing cup.

31. Install the right side service spacer between the axle housing and the differential assembly.
32. Install the right side selective service shim or shims using the J 25588 , if necessary.

The service shim or shims must be installed between the service spacer and the differential side bearing cup.

33. Install the differential bearing caps and the bolts.

Tighten
Tighten the differential bearing cap bolts to 63 N·m (46 lb ft).

34. Measure the drive pinion and differential side bearing preload using an inch-pound torque wrench.

Rotate the pinion several times to ensure the differential side bearings have seated.

Specification
The rotating torque of the drive pinion and differential side bearings should be 3.9-6.2 N·m (30-55 lb in) for new bearings or 2.8-5.1 N·m (25-45 lb in) for used bearings.

35. Record the measurement.
36. Calculate the differential side bearing preload by subtracting the drive pinion preload, measured in Step 2, from the drive pinion and differential case bearing preload, measured in Step 33.

Multiply the value obtained by the axle ratio.

Specification
The differential case side bearing preload should be 1.7-4.0 N·m (15-35 lb in).

37. If the differential side bearing preload is not within specifications, add or subtract shim thickness equally from each shim pack as necessary in order to increase/decrease the side bearing preload.
38. Once the differential side bearing preload is correct, measure the backlash and adjust, if necessary. Refer to Backlash Inspection and Adjustment .
39. Once the differential side bearing preload and backlash is correct, perform a gear tooth contact pattern check in order to ensure proper alignment between the ring and pinion gears. Refer to Gear Tooth Contact Pattern Inspection .