Differential Carrier Bearing Preload Adjustment 8.6 Inch Axle

Special Tools

Note: 

1. Install the drive pinion, if necessary. Refer to Drive Pinion and Ring Gear Replacement.

Note:  Record the measurement for re-assembly.

2. Using an inch pound torque wrench, measure the rotating torque of the drive pinion, it 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.

Note: 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.

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

7. Install the J 22779 gage into the right side of the axle housing.

Note: Over-tightening of the J 22779 gage may spread the housing and result in incorrect shim selection.

8. Tighten the knob on the J 25588 installer until there is moderate drag when the J 22779 gage is moved.
9. Remove the J 22779 gage .
10. Remove the service spacer.

Note:  Record the measurement.

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

Note:  Record the measurement.

12. Using a micrometer, measure the thickness of the J 22779 gage in 3 locations. Calculate the average of the 3 measurements.
13. Add the thickness of the service spacer, measured in step 11 to the average thickness of the J 22779 gage , 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 gage into the left side of the axle housing. The J 22779 gage 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 gage 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 gage .
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 gage 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 installer , if necessary. The service shim must be installed between the service spacer and the differential side bearing cup.

Caution: Refer to Fastener Caution in the Preface section.

29. Install the differential bearing caps and the bolts and tighten to 75 N·m (55 lb ft).
30. Rotate the pinion several times to ensure the drive pinion and differential side bearings have seated.

Note: Record the measurement.

31. Using an inch pound torque wrench, measure the rotating torque of the drive pinion and differential side bearings which should be 0.57-1.13 N·m (5-10 lb in) greater than the rotating torque of the drive pinion measured earlier.
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 31. Multiply the value obtained by the axle ratio. 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.

Special Tools

J 25588 Side Bearing Shim Installer

Note: 

1. Install the drive pinion, if necessary. Refer to Drive Pinion and Ring Gear Replacement.

Note: Record the measurement.

2. Using an inch pound torque wrench, measure the rotating torque of the drive pinion which 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.

Note: 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.

Note: Using a micrometer, verify the thickness of the service shim. Measure the service shim in 3 locations.

16. Select the correct service shim thickness for each side corresponding to the measurements determined above. Calculate the average of the 3 measurements. Use the average as the thickness for the shim.

Note: The service shim must be installed between the service spacer and the differential side bearing cup.

17. Install the left side service shim into the axle housing.
18. Move the differential assembly towards the left side of the axle housing.

Note: The service shim must be installed between the service spacer and the differential side bearing cup

19. Using the J 25588 installer , install the right side service shim into the axle housing..

Caution: Refer to Fastener Caution in the Preface section.

20. Install the differential bearing caps and bolts and tighten to 75 N·m (55 lb ft).
21. Rotate the pinion several times to ensure the bearings have seated.
22. Using an inch-pound torque wrench, measure the rotating torque of drive pinion and differential case side bearings which should be 0.57-1.13 N·m (5-10 lb in) greater than the rotating torque of the drive pinion measured earlier.
23. Calculate the differential side bearing preload by subtracting the drive pinion preload, measured in Step 2, from the drive pinion and the differential case bearing preload, measured in Step 23. Multiply the value obtained by the axle ratio.The differential side bearing preload should be 1.7-4.0 N·m (15-35 lb in).
24. 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.
25. 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.
26. 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.

Differential Carrier Bearing Preload Adjustment 9.75, 10.5 and 10.75 Inch Axle

Special Tools

J 24429 Side Bearing Backlash Spanner

Note: The rotating torque of the drive pinion must be within specifications before the differential case assembly can be installed.

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 2.3-5.1 N·m (20-45 lb in).

3. Record the measurement.
4. Install the differential side bearings, if necessary. Refer to Differential Side Bearings Replacement.
5. Install the differential side bearing adjusters.

Note: 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.

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

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

9. Install the differential bearing cap bolts.

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

10. 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.

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

11. Check for ZERO backlash.
12. While holding the ring gear against the pinion, turn the left differential bearing adjuster out from the axle housing using the J 24429 until it contacts the differential side bearing.
13. Turn the right differential bearing adjuster out from the axle housing using the J 24429 until it contacts the differential side bearing.
14. Back off the left differential adjuster approximately 2 slots using the J 24429 in order to obtain the initial backlash adjustment.
15. Using the J 24429 , tighten the right differential bearing adjuster until the differential case is in contact with the left differential adjuster.
16. Using the J 24429 , tighten the left and the right differential bearing adjuster one additional slot.
17. Rotate the pinion several times in order to seat the bearings.
18. Measure the drive pinion and differential case side bearing preload using an inch-pound torque wrench.

Specification
The rotating torque of the drive pinion and differential case bearings should be 4.0-6.4 N·m (35-57 lb in).

19. If the rotating torque of the drive pinion and differential case is less than 4.0 N·m (35 lb in), continue tighten the left and the right differential side bearing adjuster one slot at a time using the J 24429 until correct rotating torque is obtained.
20. If the rotating torque of the drive pinion and differential case is greater than 6.4 N·m (57 lb in), loosen the left and the right differential side bearing adjuster one slot at a time using the J 24429 until correct rotating torque is obtained.
21. Measure the drive pinion to ring gear backlash and adjust, if necessary. Refer to Backlash Adjustment.
22. Once the backlash is within specifications, measure the rotating torque of the drive pinion to verify that the rotating torque of the drive pinion and differential case is within specifications. If the rotating torque of the drive pinion and differential case is not within specifications, adjust the differential side bearing preload following the steps above. It may be necessary to repeat the differential side bearing preload and backlash adjustment procedures several times until both are within specifications.

Caution: Refer to Fastener Caution in the Preface section.

23. Tighten the differential bearing cap bolts to 109 N·m (80 lb ft).



24. Install the differential bearing adjuster locks.



25. Install the differential bearing adjuster lock bolts and tighten to 13 N·m (10 lb ft).