Locking Differential Adjustment (10.5 Inch Axles)
Locking Differential Adjustment (10.5 Inch Axles)
Tools Required
* J 7872 Magnetic Base Dial Indicator
* J 34672 Depth Micrometer
* J 34673 Flat Gage Bar, 2 required
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:
- The left side gear backlash
- The right side gear backlash
- The thrust block clearance
Left Side Gear Backlash Adjustment
1. Install the original locking differential clutch disc thrust washer into the differential case half.
2. Install the differential side gear cam unit and clutch disc assembly into the differential case half.
3. Clamp the differential side gear cam unit and clutch disc assembly in place using a set of washers, a nut, and a bolt long enough to hold the side gear in place.
4. Install the differential case half into a vise.
Clamp on the nut on the bottom of the case.
5. Install the differential pinion gears, the differential pinion gear thrust washers and the locking differential spider into the case half.
6. Loosen the bolt in order to turn the differential side gear.
7. Index the pinion gear so that one tooth is pointing downward, perpendicular to the case half face.
8. Tighten the bolt until the clutch plates are compressed.
9. Install the J 7872 onto the differential case.
10. Loosely clamp the J 8001-3 onto the stem of the J 7872 .
11. Place the contact pad of the J 8001-3 on the tooth that is perpendicular to the differential side gear.
12. Preload the dial of the J 8001-3 approximately 1 turn clockwise.
13. Tighten the lock nut on the J 7872 finger tight.
14. Turn the dial of the J 8001-3 until the needle and the dial face indicate ZERO.
15. Measure the differential pinion gear to locking differential side gear backlash by performing the following steps:
1. Pull the pinion gear firmly into the seat.
2. 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.
3. Record the measurement.
16. 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 pinon gear and locking differential side gear should be between 0.279-0.432 mm (0.011-0.017 in).
17. If the backlash is too large, install a thicker locking differential side gear thrust washer and check the backlash.
18. If the backlash is too small, use a thinner locking differential side gear thrust washer and check the backlash.
Locking differential clutch disc thrust washers are available in the following sizes:
* 0.56 mm (0.022 in)
* 0.69 mm (0.027 in)
* 0.81 mm (0.032 in)
* 0.91 mm (0.036 in)
* 1.02 mm (0.040 in)
* 1.07 mm (0.042 in)
* 1.12 mm (0.044 in)
* 1.22 mm (0.048 in)
* 1.32 mm (0.052 in)
Right Side Gear Backlash Adjustment
1. Install the original differential side gear shim into the differential case half.
2. Install the differential side gear clutch pack assembly into the differential case half.
3. Install the differential side gear into the differential case half.
4. Clamp the differential side gear and clutch pack assembly in place using a set of washers, a nut, and a bolt long enough to hold the side gear in place.
5. Install the differential case half into a vise.
Clamp on the nut on the bottom of the case.
6. Install the differential pinion gears, the differential pinion gear thrust washers and the locking differential spider into the case half.
7. Loosen the bolt in order to turn the differential side gear.
8. Index the pinion gear so that one tooth is pointing downward, perpendicular to the case half face.
9. Tighten the bolt until the clutch plates are compressed.
10. Install the J 7872 onto the differential case.
11. Loosely clamp the J 8001-3 onto the stem of the J 7872 .
12. Place the contact pad of the J 8001-3 on the tooth that is perpendicular to the differential side gear.
13. Preload the dial of the J 8001-3 approximately 1 turn clockwise.
14. Tighten the lock nut on the J 7872 finger tight.
15. Turn the dial of the J 8001-3 until the needle and the dial face indicate ZERO.
16. 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.
17. 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 pinon gear and locking differential side gear should be between 0.051-0.203 mm (0.002-0.008 in).
18. If the backlash is too large, install a thicker differential side gear shim and check the backlash.
19. If the backlash is too small, use a thinner differential side gear shim and check the backlash.
Differential 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)
* 0.899 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)
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 into the differential case half.
2. Install the differential side gear clutch disc assembly into the differential case half.
3. Install the differential side gear into the differential case half.
4. Clamp the differential side gear and clutch disc assembly in place using a set of washers, a nut, and a bolt long enough to hold the side gear in place.
5. Install the differential case half into a vise.
Clamp on the nut on the bottom of the case.
6. Tighten the bolt until the clutch plates are compressed.
7. Install the J 34673 (2) and the J 34672 (1) onto the differential case as shown.
8. 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.
9. Measure the thickness of the J 34673 .
10. Subtract the thickness of the J 34673 from the measurement obtained in step 8.
Record the measurement. This measurement is equal to one-half of the thrust block thickness.
11. Remove the J 34673 and the J 34673 from the differential case.
12. Remove the differential case half from the vise.
13. Install the locking differential clutch disc thrust washer into the differential case half.
14. Install the differential side gear cam unit and clutch disc assembly into the differential case half.
15. Clamp the differential side gear cam unit and clutch disc assembly in place using a set of washers, a nut, and a bolt long enough to hold the side gear in place.
16. Install the differential case half into a vise.
Clamp on the nut on the bottom of the case.
17. Tighten the bolt until the clutch plates are compressed.
18. Install the J 34673 (2) and the J 34672 (1) onto the differential case as shown.
19. 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.
20. Measure the depth from the face of the J 34673 to the face of the differential case.
21. Subtract the measurement obtained in step 20 from the measurement obtained in step 19.
Record the measurement. This measurement is equal to one-half of the thrust block thickness.
22. Add the measurements in Step 10 and Step 21 together. This is the thickness for the thrust block.
23. Compare the measurement obtain in Step 22 to the thrust block sizes available. If the measurement is equal to one of the thrust block sizes available, the select that thrust block.
24. If the measurement obtained in Step 22 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 40.92 mm (1.611 in), select the 40.89 mm (1.610 in) thrust block.
Important: The backlash must be checked and adjusted to specification anytime the left and/or the right thrust washers are replaced.
25. If the measurement obtained in Step 22 is less then 40.49 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.
26. If the measurement obtained in Step 22 is greater then 41.20 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.
27. Check the left and/or right side gear backlash and adjust as necessary.
28. Check the thrust block clearance and adjust as necessary.
29. Assemble the differential. Refer to Locking Differential Assemble (8.6 Inch, 9.75 Inch Axles) (Locking Differential Assemble (8.6 Inch, 9.75 Inch Axles))Locking Differential Assemble (10.5 Inch Axle) (Locking Differential Assemble (10.5 Inch Axle)).