10.5 Inch Axle

Locking Differential Adjustment (10.5 Inch Axle)

^ Tools Required
- J 34672 Depth Micrometer
- J 34673 Flat Gage Bar (2 required)
- J 7872 Magnetic Base Dial Indicator
- J 8001 Dial Indicator Set

Adjustment of the Differential

Important: 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:
^ Build up the clutch disc packs properly. Proper clearance between the parts is critical to the operation of the unit.
^ 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.

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

Important: 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.

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. 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 discs are compressed.

12. Install the J 7872 onto the differential case.
13. Loosely clamp the J 8001-3 onto the stem of the J 7872.
14. Place the contact pad of the J 8001-3 on the tooth that is perpendicular to the differential side gear.
15. Preload the dial of the J 8001-3 approximately one turn clockwise.
16. Tighten the lock nut on the J 7872 finger tight.
17. Turn the dial of the J 8001-3 until the needle and the dial face indicate ZERO.
18. 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. Do not unseat the locking differential spider. This will make the backlash reading inaccurate.
^ Record the measurement.

19. Measure the differential pinion gear to locking differential side gear backlash on the other 2 pinion gears following the steps above.
The backlash between the differential pinion gear and locking differential side gear should be between 0.051-0.203 mm (0.002-0.008 inch).
20. If the backlash is too large, install a thicker differential side gear shim and recheck the backlash.
21. 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 inch)
^ 0.381 mm (0.015 inch)
^ 0.508 mm (0.020 inch)
^ 0.635 mm (0.025 inch)
^ 0.762 mm (0.030 inch)
^ 0.899 mm (0.035 inch)
^ 1.016 mm (0.040 inch)
^ 1.143 mm (0.045 inch)
^ 1.270 mm (0.050 inch)
^ 1.397 mm (0.055 inch)
^ 1.524 mm (0.060 inch)

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.

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

Important:
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. 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. Clamp on the nut on the bottom of the differential case.

7. Install the differential pinion gears, the differential pinion gear thrust washers and the locking differential spider into the case half.
8. Loosen the bolt in order to turn the differential side gear.
9. Index the pinion gear so that one tooth is pointing downward, perpendicular to the case half face.
10. Tighten the bolt until the clutch plates are compressed.

11. Install the J 7872 onto the differential case.
12. Loosely clamp the J 8001-3 onto the stem of the J 7872.
13. Place the contact pad of the J 8001-3 on the tooth that is perpendicular to the differential side gear.
14. Preload the dial of the J 8001-3 approximately one turn clockwise.
15. Tighten the lock nut on the J 7872 finger tight.
16. Turn the dial of the J 8001-3 until the needle and the dial face indicate ZERO.
17. 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. Do not unseat the locking differential spider. This will make the backlash reading inaccurate.
^ Record the measurement.

18. Measure the differential pinion gear to locking differential side gear backlash on the other 2 pinion gears following the steps above.
The backlash between the differential pinion gear and locking differential side gear should be between 0.279-0.432 mm (0.011-0.017 inch).
19. If the backlash is too large, install a thicker locking differential side gear thrust washer and recheck the backlash.
20. If the backlash is too small, use a thinner locking differential side gear thrust washer and recheck the backlash.
21. Locking differential side gear thrust washers are available in the following sizes:

Washer Sizes
^ 0.559 mm (0.022 inch)
^ 0.686 mm (0.027 inch)
^ 0.813 mm (0.032 inch)
^ 0.914 mm (0.036 inch)
^ 1.016 mm (0.040 inch)
^ 1.067 mm (0.042 inch)
^ 1.118 mm (0.044 inch)
^ 1.219 mm (0.048 inch)
^ 1.321 mm (0.052 inch)

Thrust Block Clearance Adjustment

Important: 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.

9. Install the J 34673 (2) and the J 34672 (1) onto the differential case as shown. Install the J 34673 onto the face of the differential case, not the ridge of the differential case, or an inaccurate measurement will result.
10. Measure the depth from the face of the J 34673 to the face of the differential side gear using the J 34672.Record the measurement.
11. Measure the thickness of the J 34673.
12. Subtract the thickness of the J 34673 from the measurement obtained in step 7.Record the measurement. This measurement is equal to one-half of the thrust block thickness.
13. Remove the J 34673 and the J 34673 from the differential case.
14. Remove the differential case half from the vise.

15. Install the locking differential clutch disc thrust washer.

16. Install the differential side gear cam unit and clutch pack assembly.
17. Assemble a set of washers, a nut, and a bolt long enough in order to hold the side gear in place.

18. Install the bolt and washer assembly through the differential case half.
19. Install a second set of washers and the nut onto the bolt extending through the differential case half.
20. Install the differential case half into a vise. Clamp on the nut on the bottom of the differential case.
21. Tighten the bolt until the clutch plates are compressed.

22. Install the J 34673 (2) and the J 34672 (1) onto the differential case as shown.
23. Measure the depth from the face of the J 34673 to the face of the differential side gear using the J 34672.Record the measurement.
24. Measure the thickness of the J 34673.
25. Subtract the thickness of the J 34673 from the measurement obtained in step 18.Record the measurement. This measurement is equal to one-half of the thrust block thickness.
26. Add the measurements in step 9 and step 20 together. This is the thickness for the thrust block.
27. Compare the measurement obtain in step 21 to the thrust block sizes available. If the measurement is equal to one of the thrust block sizes available, the select that thrust block.
28. If the measurement obtained in step 21 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 inch), select the 40.894 mm (1.610 inch) thrust block.

29. If the measurement obtained in step 21 is less then 40.488 mm (1.594 inch), 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.

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

30. If the measurement obtained in step 21 is greater then 41.120 mm (1.622 inch), 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.
31. Recheck the left and/or right side gear backlash and adjust as necessary.
32. Recheck the thrust block clearance and adjust as necessary.