Differential Carrier Bearing Preload Adjustment 8.6 Inch Axle

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.

Specification
The rotating torque of the drive pinion should be 1.7-3.4 N·m (15-30 lb in) for new bearings or 1.1-2.8 N·m(10-25 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 22, 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.

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 23 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 22.

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 24.

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.

Notice: Refer to Fastener Notice in the Preface section.

33. Install the differential bearing caps and the bolts.

Tighten
Tighten the differential bearing cap bolts to 75 N·m (55 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 2.8-5.6 N·m (25-50 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 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 .

Differential Carrier Bearing Preload Adjustment 10.5 Inch Axle

Tools Required

J 24429 Side Bearing Backlash Spanner

Important: The rotating torque of the drive pinion must be within specifications before the pinion gear bearing retain or the differential case assembly can be installed.

1. Install the pinion gear bearing retainer assembly. Refer to Drive Pinion Housing and/or Seal Replacement .

Important: The differential side bearing preload is adjusted by the 2 adjusting nuts in the bearing bore. The bore and the bearing cap provide the mating threads for the bearing nut.

The differential must be initially prelubricated in order to determine the backlash of the gear set. After the backlash is set, the final bearing preload is set.
2. Install the differential side bearings, if necessary. Refer to Differential Side Bearings Replacement .
3. Install the differential side bearing adjuster nuts.

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

If the differential case assembly cannot be installed, turn the differential side bearing adjuster nuts into the axle housing until the differential case assembly until the proper clearance can be obtained.
4. Install the differential case assembly.
5. Install the differential bearing caps.
6. Install the differential bearing cap bolts.

Important: In the following service procedure, DO NOT torque the bearing cap bolts, only finger tighten them.

7. Install the bearing cap bolts.

Important: DO NOT FORCE the ring gear into contact with the drive pinion.

8. Slide the differential case assembly towards the right side axle housing until the ring gear contact the pinion (this is the zero backlash point).

Important: If the zero backlash cannot be obtained, turn the right side differential bearing adjuster nut in towards the axle housing until the ring gear fully contacts the pinion to obtain the zero backlash.

9. Check for zero backlash.
10. While holding the ring gear against the pinion, turn the left differential bearing adjuster nut out from the axle housing using the J 24429 until it contacts the differential side bearing.
11. Turn the right differential bearing adjuster nut out from the axle housing using the J 24429 until it contacts the differential side bearing.
12. Back off the left adjusting nut approximately 2 slots using the J 24429 in order to obtain the initial backlash adjustment.

Important: In the following service procedure, DO NOT torque the adjuster nut lock bolt.

13. Install the left adjuster nut lock and the adjuster nut lock bolt.
14. Using the J 24429 , tighten the right differential bearing adjuster nut until the differential case is in contact with the left differential adjuster nut.
15. Rotate the pinion several times in order to seat the bearings.
16. Loosen the right differential bearing adjuster nut using the J 24429 until the nut is free from the differential side bearing.
17. Tighten the right differential bearing adjuster nut using the J 24429 until the differential bearing adjuster nut contacts the bearing.
18. Once the right differential bearing adjuster contacts the differential bearing, tighten the differential bearing adjuster nut using the J 24429 the following additional amounts:

Tighten

•	For used bearings, tighten the differential bearing adjuster nut an additional 2 slots.

•	For new bearings, tighten the differential bearing adjuster nut an additional 3 slots.

19. Install the right differential bearing adjuster nut lock.

Important: In the following service procedures, DO NOT torque the bolt at this time

20. Install the right differential bearing adjuster nut lock bolt.

Notice: Refer to Fastener Notice in the Preface section.

21. Tighten the bearing cap bolts.

Tighten
Tighten the bearing cap bolts to 185 N·m (136 lb ft).

22. Tighten differential bearing adjuster nut lock bolts.

Tighten
Tighten the differential bearing adjuster nut lock bolts to 27 N·m (20 lb ft).

23. Measure the ring gear to pinion backlash and adjust, if necessary. Refer to Backlash Adjustment .

Differential Carrier Bearing Preload Adjustment 9.5 Inch Axle

Tools Required

Important: 

Caution: To prevent personal injury and/or component damage, support the differential case when removing the case from the axle housing. If the case is not supported, the differential case could fall and cause personal injury or damage to the differential case.

1. Remove the differential assembly, if necessary.
2. Measure the rotating torque of the drive pinion bearing 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. If the rotating torque of the drive pinion is less than 1.7 N·m (15 lb in) for new bearings or 1.1 N·m (10 lb in) for used bearings, tighten the pinion in small increments until the specified rotating torque is obtained.
4. If the rotating torque of the drive pinion is greater than 3.4 N·m (30 lb in) for new bearings or 2.3 N·m (20 lb in) for used bearings, remove the drive pinion and replace the collapsible spacer and re-install the drive pinion. Refer to Drive Pinion Bearings Replacement .
5. Install the differential assembly, if necessary.
6. Support the differential assembly in order to prevent the differential assembly from falling out of the axle housing.

Important: Do not force the ring gear into contact with the drive pinion.

7. Slide the differential case assembly towards the right side axle housing until the ring gear contacts the drive pinion.

This is the ZERO backlash point.

If the ZERO backlash cannot be obtained, turn the differential bearing adjuster nut into the axle housing using the J 24429 until the ring gear fully contacts the drive pinion to obtain the ZERO backlash.

8. While holding the ring gear against the pinion, turn the differential bearing adjuster nut out from the axle housing using the J 24429 until it contacts the differential side bearing.
9. Turn the adjuster nut out from the axle housing an additional 2 slots using the J 24429 in order to obtain the initial backlash adjustment.
10. Install the adjuster nut lock and the adjuster nut lock bolt.
11. Remove the left side differential bearing cap bolts.
12. Remove the left side differential bearing cap.



13. Install the J 22779 into the left side axle housing between the differential bearing bore and the differential bearing cup.

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

14. Tighten the knob of the J 22779 until there is moderate drag when the J 22779 is moved.
15. Remove the J 22779 .
16. Measure the J 22779 in 3 locations.
17. Calculate the average of the 3 measurements.

The resulting value is the shim thickness required in order to set the initial backlash of the differential assembly.

18. Select a service shim of approximately the same thickness to install into the axle housing.

Verify the thickness of the service shim using a micrometer.

19. Install the service shim into the axle housing between the differential bearing bore and the differential bearing cup.
20. Install the left side differential bearing cap.
21. Install the left side differential bearing cap bolts.

Tighten the differential bearing cap bolts finger-tight. Do not torque the bolts at this time.

22. Remove the differential bearing adjuster nut lock bolt.
23. Remove the differential bearing adjuster nut lock.
24. Firmly tighten the differential bearing adjuster nut using the J 24429 in order to force the differential case assembly into solid contact with the service shim.
25. Rotate the pinion several times in order to seat the bearings.
26. Loosen the differential bearing adjuster nut using the J 24429 until the nut is free from the differential side bearing.
27. Tighten the differential bearing adjuster nut using the J 24429 until the differential bearing adjuster nut contacts the bearing.
28. Once the right differential bearing adjuster contacts the differential bearing, tighten the differential bearing adjuster nut using the J 24429 the following additional amounts:

Tighten

•	For new bearings, tighten the differential bearing adjuster nut an additional 3 slots.

•	For used bearings, tighten the differential bearing adjuster nut an additional 2 slots.

29. Install the right differential bearing adjuster nut lock.
30. Install the right differential bearing adjuster nut lock bolt.

Do not torque the bolt at this time.

Notice: Refer to Fastener Notice in the Preface section.

31. Tighten the bearing cap bolts.

Tighten
Tighten the bearing cap bolts to 85 N·m (63 lb ft).

32. Tighten the differential bearing adjuster nut lock bolt.

Tighten
Tighten the differential bearing adjuster nut lock bolt to 26 N·m(19 lb ft).

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

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

Specification
The rotating torque of the drive pinion and differential case 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.

Record the measurement.

34. 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).

35. If the differential case side bearing preload is not within specifications, increase or decrease the shim thickness as necessary in order to increase/decrease the side bearing preload.
36. Once the differential side bearing preload is correct, measure the drive pinion to differential assembly backlash and adjust, if necessary. Refer to Backlash Adjustment .

Differential side bearing shims are available in the following sizes:

Shim Sizes