Tools Required

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. Record the measurement.

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. If the rotating torque for the drive pinion bearings is not within specifications, adjust as necessary. Refer to Drive Pinion and Ring Gear Replacement .

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

4. Install the differential assembly with the differential side bearings and differential side 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 into the right side of the axle housing.

The J 22779 must be installed between the service spacer and the differential side bearing cup.

Important: Over-tightening of the J 22779 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 service spacer. Record the measurement.
12. Using a micrometer, measure the thickness of the J 22779 in 3 locations. Calculate the average of the 3 measurements. Record the measurement.
13. Add the thickness of the service spacer, measured in Step 11 to the average thickness of the J 22779 , measured in Step 12. The resulting value is the total service shim thickness without preload for the axle.
14. Insert one BENT 1.016 mm (0.040 in) service shim between the right side differential side bearing cup and the axle housing. The service shim must be installed between the service spacer and the differential side bearing cup.
15. Install the J 22779 into the left side of the axle housing. The J 22779 must be installed between the service spacer and the differential side bearing cup.
16. 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.
17. Once the correct amount of backlash is obtained, remove the J 22779 .
18. Remove the differential assembly with the differential side bearings and the differential side bearing cups.
19. Remove the BENT service shim.
20. Using a micrometer, measure the thickness of the J 22779 in 3 locations. Calculate the average of the 3 measurements. This value is the left side service shim thickness without preload.
21. In order to determine the right side service shim thickness, subtract the service shim thickness for the left side of the axle, calculated in step 20, from the total service shim thickness, calculated in step 13. This value is the service shim thickness for the right side of the axle without preload.
22. In order to preload of the differential side bearings and set the backlash to approximately 0.127-0.223 mm (0.005-0.009 in), take the value determined in step 21 and add 0.203 mm (0.008 in) service shim thickness to this amount.
23. Assemble the left side shim pack using one 4.318 mm (0.170 in) service spacer and the appropriate amount of service shims equaling the thickness determined in step 20. Measure the service spacer and the service shims separately. Add the measurements together in order to determine the total shim pack thickness.
24. Assemble the right side shim pack using one 4.318 mm (0.170 in) service spacer and the appropriate amount of service shims equaling the thickness determined in step 22. Measure the service spacer and the service shims separately. Add the measurements together in order to determine the total shim pack thickness.
25. Install the differential assembly with the differential side bearings and the differential side bearing cups.
26. Install the left side service spacer and service shim into the axle housing. The service shim must be installed between the service spacer and the differential side bearing cup.
27. Install the right side service spacer between the axle housing and the differential side bearing cup.
28. Install the right side service shim into the axle housing using the J 25588 , if necessary. The service shim must be installed between the service spacer and the differential side bearing cup.

Notice: Refer to Fastener Notice in the Preface section.

29. Install the differential bearing caps and the bolts.

Tighten
Tighten the differential bearing cap bolts to 75 N·m (55 lb ft).

30. Rotate the pinion several times to ensure the drive pinion and differential side bearings have seated.
31. Measure the rotating torque of the drive pinion and differential side bearings using an inch-pound torque wrench. Record the measurement.

Specification
The rotating torque of the drive pinion and differential side bearings should be approximately 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.

32. 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 side bearing preload should be 1.7-4.0 N·m (15-35 lb in).

33. 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.
34. Once the differential side bearing preload is correct, measure the backlash and adjust, if necessary. Refer to Backlash Adjustment .
35. 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 .

Tools Required

J 25588 Side Bearing Shim Installer

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. Record the measurement.

Specification
The rotating torque for the drive pinion bearings 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. If the rotating torque for the drive pinion bearings is not within specifications, adjust as necessary. Refer to Drive Pinion and Ring Gear Replacement .

Important: Before installation of the case 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 differential side bearings and bearing cups into the axle housing.
5. Insert one BENT 1.016 mm (0.040 in) thick service shim into the right side axle housing. Side the differential assembly towards the bent service shim in order to hold the shim in place.
6. While holding the differential assembly against the bent service shim, install one 4.318 mm (0.170 in) thick service spacer into the left side axle housing.
7. Move the differential assembly to the right until the ring gear contacts the drive pinion. Once the ring gear contacts the drive pinion, continue to move the ring gear towards the drive pinion to until all backlash is removed.
8. While holding the ring gear against the drive pinion, insert progressively larger service shims between the service spacer and the differential side bearing cup until a moderate resistance can be felt.
9. Once the largest service shim has been determined, measure the thickness of the shim using a micrometer. Measure the service shim in 3 locations. Calculate the average of the 3 measurements. Use the average as the thickness for the shim. Record the measurement.
10. Install the service shim that was just measured back into the left side of the axle housing. The service shim must be installed between the service spacer and the differential side bearing cup.
11. Remove the BENT shim from the right side of the axle housing.
12. Insert one 4.318 mm (0.170 in) thick service spacer into the right side axle housing.
13. Move the differential assembly towards the left side of the axle housing. While holding the differential assembly against the left side shim pack, insert progressively larger service shims between the service spacer and the differential side bearing cup until a moderate resistance can be felt.
14. Once the largest service shim has been determined, measure the thickness of the shim using a micrometer. Verify the thickness of the service shim. Measure the service shim in 3 locations. Calculate the average of the 3 measurements. Use the average as the thickness for the shim. Record the measurement.
15. In order to preload the differential side bearing and set the initial backlash to approximately 0.127 mm (0.005 in), adjust the thickness of left and right side shims by doing the following:

15.1.

Subtract 0.152 mm (0.006 in) from the measurement recorded for the left side shim in step 9. Record the measurement.

15.2.

Add 0.356 mm (0.014 in) to the measurement recorded for the right side shim in step 14.

16. Select the correct service shim thickness for each side corresponding to the measurements determined above. Using a micrometer, verify the thickness of the service shim. Measure the service shim in 3 locations. Calculate the average of the 3 measurements. Use the average as the thickness for the shim.
17. Install the left side service shim into the axle housing. The service shim must be installed between the service spacer and the differential side bearing cup.
18. Move the differential assembly towards the left side of the axle housing.
19. Install the right side service shim into the axle housing using the J 25588 , if necessary. The service shim must be installed between the service spacer and the differential side bearing cup.
20. Install the differential bearing caps and bolts.

Tighten
Tighten the differential bearing cap bolts to 75 N·m (55 lb ft).

21. Rotate the pinion several times to ensure the bearings have seated.
22. Measure the rotating torque of drive pinion and differential case side bearings using an inch-pound torque wrench.

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 2.8-5.6 N·m (25-50 lb in) for used bearings.

23. Record the measurement.
24. Determine the preload for the differential side bearings by performing the following calculation:

23.1.

Subtract the drive pinion rotating torque, measured in step 2, from the drive pinion and differential case side bearing rotating torque, measured in step 22.

23.2.

Multiply the value obtained by the axle ratio. This value equals the preload for the differential side bearings.

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

25. 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.
26. Once the differential side bearing preload is within specifications, measure the backlash between the ring gear and the drive pinion and adjust, if necessary. Refer to Backlash Adjustment .
27. Once backlash and differential side bearing preload is within specifications, 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 .