Locking Differential Adjustment (11.5 Inch Axle)
Locking Differential Adjustment (11.5 Inch Axle)
Special Required
* J 7872 - Magnetic Base Dial Indicator
* J 8001 - Dial Indicator Set
Adjustment of the Differential
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:
* Build up the clutch disc assemblies properly.
Proper clearance between 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 new left side thrust washer into the flange end of the differential case.
2. Install the left side gear cam unit and clutch disc 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.
5. Install a 7.0 mm (0.276 in) drill bit into the pinion shaft retaining pin opening to retain the pinion shaft.
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:
1. Install the J 7872 - indicator (1) to the ring gear flange.
2. Loosely the clamp J 8001-3 of the J 8001 - set (2) onto the stem on the J 7872 - indicator (1).
3. Place the contact pad of the J 8001-3 (2) on one of the teeth of the pinion gear closest to the pinion shaft lock bolt.
Turn the dial of the J 8001-3 (2) needle and the dial face indicate zero.
4. Tighten the lock nut of the J 8001-3 (2) finger tight.
5. Pull the pinion gear firmly into the differential case seat.
6. Rotate the pinion gear back and forth.
7. The measured backlash for the pinion gears should be 0.279-0.457 mm (0.011-0.018 in).
9. If the backlash is too large, install a thicker side gear thrust washer and recheck the backlash.
10. If the backlash is too small, install a thinner side gear thrust washer and recheck the backlash.
11. Thrust washers are available in the following 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)
* 1.118 mm (0.044 in)
* 1.219 mm (0.048 in)
* 1.321 mm (0.052 in)
Right Side Gear Backlash Adjustment
1. If necessary, remove the following from the differential case:
1. The pinion lock shaft bolt
2. The pinion shaft
3. The pinion gears
4. The pinion gear thrust washers
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 disc 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 a 7.0 mm (0.276 in) drill bit into the pinion shaft retaining pin opening to retain the pinion shaft.
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:
1. Install the J 7872 - indicator (1) to the ring gear flange.
2. Loosely the clamp J 8001-3 of the (2)J 8001 - set onto the stem on the J 7872 - indicator (1).
3. Place the contact pad of the J 8001-3 (2) on one of the teeth of the pinion gear closest to the pinion shaft lock bolt.
4. Adjust the dial of the J 8001-3 (2) until dial face indicate zero.
5. Tighten the lock nut of the J 8001-3 (2) finger tight.
6. Pull the pinion gear firmly into the differential case seat.
7. Rotate the pinion gear back and forth.
8. The measure backlash for the pinion gears should be 0.051-0.229 mm (0.002-0.009 in).
10. If the backlash is too large, install a thicker side gear shim and recheck the backlash.
11. If the backlash is too small, install a thinner side gear shim and recheck the backlash again.
12. Right side gear shims are available in the following 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)
* 0.889 mm (0.035 in)
* 1.016 mm (0.040 in)
* 1.143 mm (0.045 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 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 a 7.0 mm (0.276 in) drill bit into the pinion shaft retaining pin opening to retain the pinion shaft.
Note: Press the brass drift in far enough in order to compress the clutch disc assembly and hold the left side gear assembly in place.
7. Install a brass drift between the left side gear and the pinion shaft.
Note: Press the brass drift in far enough in order to hold the right side gear assembly in place.
8. Install a brass drift between the right side gear and the pinion shaft.
Note: Do not measure the distance between the side gear teeth.
9. Using a 25.4-50.8 mm (1-2 in) telescoping gauge, measure the distance between the side gear faces.
10. Remove the telescoping gauge.
11. Using micrometer, measure the telescoping gauge and record the measurement.
Note: If the measurement is equal to one of the thrust blocks sizes available, then select that thrust block.
12. Compare the measurement obtained in Step 11 to the thrust block sizes available.
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 46.43 mm (1.827 in), select the 46.35 mm (1.825 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 46.055 mm (1.813 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 46.755 mm (1.841 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. Recheck the left and/or right side gear backlash and adjust as necessary.
17. Recheck the thrust block clearance and adjust as necessary.