Locking Differential Adjustment (10.5 Inch Axle)

Locking Differential Adjustment (10.5 Inch Axle)

Special Tools

* J 7872 - Magnetic Base Dial Indicator

* J 8001 - Dial Indicator Set

* J 34672 - Depth Micrometer

* J 34673 - Flat Gauge Bar

Adjustment of the Differential

Note:
If it is necessary to replace the right side cam gear and clutch disc assembly, the left hand side gear and clutch disc assembly, or the thrust block, the entire differential must be adjusted. The differential is adjusted using selective thickness thrust washers between the clutch pack assemblies and case and/or different selective thickness thrust blocks.

When adjusting the differential, note the following:

Note:
Proper clearance between the parts is critical to the operation of the unit.

* Build up the clutch disc packs properly.

* Adjust the backlash and thrust block clearance in the following order:

1. The left side gear backlash

2. The right side gear backlash

3. The thrust block clearance

Left Side Gear Backlash Adjustment

1. Install the differential side gear shim.

2. Install the clutch pack assembly.

3. Install the differential side gear.

Note:
The washers must be large enough in order to fit over the differential side gear, but not too large to where they will cause an interference with the pinion gear and spider assembly.

4. Assemble a set of washers, a nut, and a bolt long enough in order to hold the side gear in place.

5. Install the bolt and washer assembly through the differential case half.

6. Install a second set of washers and the nut onto the bolt extending through the differential case half.

7. Install the differential case half into a vise.

8. Clamp on the nut on the bottom of the differential case.

9. Install the differential pinion gears, the differential pinion gear thrust washers and the locking differential spider into the case half.

10. Loosen the bolt in order to turn the differential side gear.

11. Index the pinion gear so that one tooth is pointing downward, perpendicular to the case half face.

12. Tighten the bolt until the clutch discs are compressed.

13. Install the J 7872 - indicator onto the differential case.

14. Loosely clamp the J 8001-3 onto the stem of the J 7872 - indicator.

15. Place the contact pad of the J 8001-3 on the tooth that is perpendicular to the differential side gear.

16. Preload the dial of the J 8001-3 approximately one turn clockwise.

17. Tighten the lock nut on the J 7872 - indicator finger tight.

18. Turn the dial of the J 8001-3 until the needle and the dial face indicate ZERO.

Note:
In the following procedure, DO NOT unseat the locking differential spider. This will make the backlash reading inaccurate.

19. Measure the differential pinion gear to locking differential side gear backlash by performing the following steps:

* Pull the pinion gear firmly into the seat.

* Rotate the pinion gear back and forth while reading the dial indicator.

* Record the measurement.

Note:
Measure the differential pinion gear to locking differential side gear backlash on the other 2 pinion gears

20. The measured backlash between the differential pinon gear and locking differential side gear should be 0.051-0.203 mm (0.002-0.008 in).

21. If the backlash is too large, install a thicker differential side gear shim and recheck the backlash.

22. If the backlash is too small, use a thinner differential side gear shim and recheck the backlash.

Differential side gear shims are available in the following sizes:

Shim Sizes

* 0.254 mm (0.010 in)

* 0.381 mm (0.015 in)

* 0.508 mm (0.020 in)

* 0.635 mm (0.025 in)

* 0.762 mm (0.030 in)

* 0.899 mm (0.035 in)

* 1.016 mm (0.040 in)

* 1.143 mm (0.045 in)

* 1.270 mm (0.050 in)

* 1.397 mm (0.055 in)

* 1.524 mm (0.060 in)

Right Side Gear Backlash Adjustment

1. Install the locking differential clutch disc thrust washer.

2. Install the differential side gear cam unit and clutch pack assembly.

Note:
The washers must be large enough in order to fit over the differential side gear but not too large to where they will cause an interference with the pinion gear and spider assembly.

3. Assemble a set of washers, a nut, and a bolt long enough in order to hold the side gear in place.

4. Install the bolt and washer assembly through the differential case half.

5. Install a second set of washers and the nut onto the bolt extending through the differential case half.

6. Install the differential case half into a vise.

7. Clamp on the nut on the bottom of the differential case.

8. Install the differential pinion gears, the differential pinion gear thrust washers and the locking differential spider into the case half.

9. Loosen the bolt in order to turn the differential side gear.

10. Index the pinion gear so that one tooth is pointing downward, perpendicular to the case half face.

11. Tighten the bolt until the clutch plates are compressed.

Note:
In the following procedure, DO NOT unseat the locking differential spider. This will make the backlash reading inaccurate.

12. Measure the differential pinion gear to locking differential side gear backlash by performing the following steps:

* Pull the pinion gear firmly into the seat.

* Rotate the pinion gear back and forth while reading the dial indicator.

* Record the measurement.

13. The backlash between the differential pinon gear and locking differential side gear should be between 0.279-0.432 mm (0.011-0.017 in).

14. If the backlash is too large, install a thicker locking differential side gear thrust washer and recheck the backlash.

15. If the backlash is too small, use a thinner locking differential side gear thrust washer and recheck the backlash.

16. Locking differential side gear thrust washers are available in the following sizes:

Washer Sizes

* 0.559 mm (0.022 in)

* 0.686 mm (0.027 in)

* 0.813 mm (0.032 in)

* 0.914 mm (0.036 in)

* 1.016 mm (0.040 in)

* 1.067 mm (0.042 in)

* 1.118 mm (0.044 in)

* 1.219 mm (0.048 in)

* 1.321 mm (0.052 in)

Thrust Block Clearance Adjustment

Note:
The left and right side gear backlash measurements must be done before the thrust block measurement can be completed.

1. Install the differential side gear shim.

2. Install the clutch pack assembly.

3. Install the differential side gear.

4. Assemble a set of washers, a nut, and a bolt long enough in order to hold the side gear in place.

Note:
You will need two of the J 34673 to perform the following service procedure.

10. Install the J 34673 - bar, J 34672 - micrometer (2) and the J 34672 - micrometer (1) onto the differential case as shown.

11. Install the J 34673 - bar onto the face of the differential case, not the ridge of the differential case, or an inaccurate measurement will result.

12. Measure the depth from the face of the J 34673 - bar to the face of the differential side gear using the J 34672 - micrometer.

Record the measurement.

13. Measure the thickness of the J 34673 - bar.

14. Subtract the thickness of the J 34673 - bar from the measurement obtained in step 10.

15. Record the measurement. This measurement is equal to one-half of the thrust block thickness.

16. Remove both of the J 34673 - bar from the differential case.

17. Remove the differential case half from the vise.

18. Install the locking differential clutch disc thrust washer.

19. Install the differential side gear cam unit and clutch pack assembly.

20. Assemble a set of washers, a nut, and a bolt long enough in order to hold the side gear in place.

21. Install the bolt and washer assembly through the differential case half.

22. Install a second set of washers and the nut onto the bolt extending through the differential case half.

23. Install the differential case half into a vise.

24. Clamp on the nut on the bottom of the differential case.

25. Tighten the bolt until the clutch plates are compressed.

26. Install the J 34673 - bar (2) and the J 34672 - micrometer (1) onto the differential case.

27. Measure the depth from the face of the J 34673 - bar to the face of the differential side gear using the J 34672 - micrometer. Record the measurement.

28. Measure the thickness of the J 34673 - bar.

29. Subtract the thickness of the J 34673 - bar from the measurement obtained in step 23.

30. Record the measurement. This measurement is equal to one-half of the thrust block thickness.

31. Add the measurements in step 12 and step 25 together. This is the thickness for the thrust block.

32. Compare the measurement obtain in step 25 to the thrust block sizes available. If the measurement is equal to one of the thrust block sizes available, the select that thrust block.

33. If the measurement obtained in step 25 is not equal to one of the thrust block sizes available, then select the thrust block that is smaller the measurement. For example, if the measurement is 40.919 mm (1.611 in), select the 40.894 mm (1.610 in) thrust block.

Note:
The backlash must be rechecked and adjusted to specification anytime the left and/or the right thrust washers are replaced.

34. If the measurement obtained in step 25 is less then 40.488 mm (1.594 in), then reduce the left differential side gear shim or the right locking differential clutch disc thrust washer thickness in order to increase the thrust block opening.

35. If the measurement obtained in step 25 is greater then 41.120 mm (1.622 in), then increase the left differential side gear shim or the right locking differential clutch disc thrust washer thickness in order to decrease the thrust block opening.

36. Recheck the left and/or right side gear backlash and adjust as necessary.

37. Recheck the thrust block clearance and adjust as necessary.