Special Tools

Note: If it is necessary to replace the left side gear (cam unit) and disc assembly, the right side gear and 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 the case and/or different selective thickness thrust blocks.

When adjusting the differential, note the following:

1. Install the new left side thrust washer into the flange end of the differential case.



2. Install the left side gear (cam unit) and clutch pack assembly into the differential case.
3. Install the pinion gears with the pinion thrust washers into the differential case.

Align the openings of the pinion gears and the pinion thrust washer to the pinion shaft opening in the differential case.

4. Install the pinion shaft. It may be necessary to press down on the side gear in order to align the pinion gear shaft opening with the pinion shaft opening in the differential case.

If the pinion shaft cannot be installed after pressing on the side gear, replace the side gear thrust washer with a thinner washer.

Caution: Refer to Fastener Caution in the Preface section.

5. Install the pinion shaft lock bolt.

Tighten the pinion shaft lock bolt finger tight.

6. Rotate the pinion gear closest to the lock bolt so that one of the teeth is pointing downward, perpendicular to the ring gear flange.
7. Install a brass drift between the side gear and the pinion shaft.

Press the brass drift in far enough in order to compress the clutch discs.




8. Measure the backlash of the pinion gear and the side gear by doing the following:

8.1.	Install the J 7872  (1) to the ring gear flange.

8.2.	Loosely clamp the J 8001-3  (2) onto the stem on the J 7872  (1).

8.3.	Place the contact pad of the J 8001-3 on one of the teeth of the pinion gear closest to the pinion shaft lock bolt.

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

Tighten
Tighten the lock nut of the J 8001-2 finger tight.

8.4.	Pull the pinion gear firmly into the differential case seat.

8.5.	Rotate the pinion gear back and forth.

8.6.	Measure the backlash.

Specification
The backlash for the pinion gears should be 0.000-0.076 mm (0.000-0.003 in).

9. If the backlash is too large, install a thicker side gear thrust washer and inspect the backlash.
10. If the backlash is too small, install a thinner side gear thrust washer and inspect the backlash.

Left side gear thrust washers are available in the following sizes:

Washer Sizes

•	0.56 mm (0.022 in)

•	0.68 mm (0.027 in)

•	0.81 mm (0.032 in)

•	0.91 mm (0.036 in)

•	1.02 mm (0.040 in)

•	1.12 mm (0.044 in)

•	1.22 mm (0.048 in)

•	1.32 mm (0.052 in)

1. If necessary, remove the following from the differential case:

1.1.	The pinion lock shaft bolt

1.2.	The pinion shaft

1.3.	The pinion gears

1.4.	The pinion gear thrust washers

1.5.	The left side gear (cam unit) and clutch disc assembly

2. Install the right side gear thrust washer into the bell-end of the differential case.
3. Install the right side gear and clutch pack assembly into the differential case.
4. Install the pinion gears with the pinion thrust washers into the differential case.

Align the openings of the pinion gears and the pinion thrust washer to the pinion shaft opening in the differential case.

5. Press down on the side gear and install the pinion shaft.

If the side gear cannot be pressed down far enough to install the pinion shaft, replace the side gear shim with a thinner shim.

6. Install the pinion shaft lock bolt.

Tighten
Tighten the pinion shaft lock bolt finger tight.

7. Rotate the pinion gear so that one of the teeth is pointing downward, perpendicular to the ring gear flange.



8. Install a brass drift between the side gear and the pinion shaft.

Press the brass drift in enough, in order to compress the clutch discs.




9. Measure the backlash of the pinion gear and the right side gear by doing the following:

9.1.	Install the J 7872  (1) to the ring gear flange.

9.2.	Loosely clamp the J 8001-3  (2) onto the stem on the J 7872  (1).

9.3.	Place the contact pad of the J 8001-3 on one of the teeth of the pinion gear closest to the pinion shaft lock bolt.

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

9.4.	Tighten the lock nut of the J 8001-2 finger tight.

9.5.	Pull the pinion gear firmly into the differential case seat.

9.6.	Rotate the pinion gear back and forth.

9.7.	Measure the backlash.

Specification
The backlash for the pinion gears should be 0.000-0.076 mm (0.000-0.003 in).

10. Right 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)

11. If the backlash is too large, install a thicker side gear shim and recheck the backlash.
12. If the backlash is too small, install a thinner side gear shim and recheck the backlash again.

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

1. Install the left side gear thrust washer into the differential case.



2. Install the left side gear (cam unit) and clutch disc assembly into the differential case.
3. Install the right side shim into the differential case.
4. Install the right side gear and clutch disc assembly into the differential case.
5. Install the pinion shaft.
6. Install the pinion shaft bolt.

Tighten the pinion shaft bolt finger tight.




7. Install a brass drift between the left side gear and the pinion shaft.

Press the brass drift in far enough in order to compress the clutch disc assembly and hold the left side gear assembly in place.

8. Install a brass drift between the right side gear and the pinion shaft.

Press the brass drift in far enough, in order to hold the right side gear assembly in place.





Note: Do not measure the distance between the side gear teeth.

9. Measure the distance between the side gear faces using a 25.4-50.8 mm (1-2 in) telescoping gage.
10. Remove the telescoping gage.
11. Measure the telescoping gage with a micrometer. Record the measurement.
12. Compare the measurement obtained in step 11 to the thrust block sizes available. If the measurement is equal to one of the thrust blocks sizes available, then select that thrust block.
13. If the measurement obtained in step 11 is not equal to one of the thrust blocks sizes available, then select the thrust block that is smaller than the measurement.

For example, if the measurement is 32.13 mm (1.265 in), select the 32.05 mm (1.262 in) thrust block.

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

14. If the measurement obtained in step 11 is less than 31.75 mm (1.25 in), then reduce the left side gear thrust washer or the right side gear shim thickness in order to increase the thrust block opening.
15. If the measurement obtained in step 11 is greater than 32.52 mm (1.28 in), then increase the left side gear thrust washer or the right side gear shim thickness in order to decrease the thrust block opening.
16. Inspect the left and/or right side gear backlash and adjust as necessary.
17. Inspect the thrust block clearance and adjust as necessary.