Locking Differential Adjustment (10.5 Inch Axle)
Locking Differential Adjustment
Special Tools
* J 7872 - Magnetic Base Indicator
* J 8001 - Dial Indicator
* 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: The proper clearance between the parts is critical to the operation of the unit.
* Assemble the clutch disc sets 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 locking differential clutch disc thrust washer.
2. Install the locking differential clutch disc set.
3. Install the differential side gear.
Note:
* The bolt must be long enough to hold the differential side gear in place and to allow the use of washers and nut.
* The washers must be the proper size in order to fit over the differential side gear, but without causing interference with the with the differential pinion gear and differential spider assembly.
* Tighten the nut and bolt just enough compress the clutch disc but will allow locking differential side gear to rotate.
4. Install the long bolt, washers and nut
5. Install the differential case half into a vise.
6. Clamp on the nut on the bottom of the differential case.
Note: Index the pinion gear so that one tooth is pointing downward, square to the case half face.
7. Install the differential pinion gears, thrust washers and the locking differential spider into the case half.
8. Install the J 7872 - base and the J 8001 - indicator on the differential case.
Note: Preload the dial of the J 8001 - indicator approximately one turn clockwise.
9. Adjust the J 8001 - indicator on the tooth that is square to the differential side gear and set the J 8001 - indicator to zero
Note: In the following procedure, DO NOT unseat the locking differential spider. This will make the backlash reading inaccurate.
10. 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.
* Record the measurement.
Note: Measure the differential pinion gear to locking differential side gear backlash on the remaining differential pinion gears following the previous steps.
11. 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).
Note:
* If the backlash is greater than, install a thicker differential side gear shim and recheck the backlash.
* If the backlash is less than, use a thinner differential side gear shim and recheck the backlash.
12. 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 locking differential cam unit.
Note:
* The bolt must be long enough to hold the differential side gear in place and to allow the use of washers and nut.
* The washers must be the proper size in order to fit over the differential side gear, but without causing interference with the with the differential pinion gear and differential spider assembly.
* Tighten the nut and bolt just enough compress the clutch disc but will allow locking differential side gear to rotate.
3. Install the long bolt, washers and nut
4. Install the differential case half into a vise.
5. Clamp on the nut on the bottom of the differential case.
Note: Index the pinion gear so that one tooth is pointing downward, square to the case half face.
6. Install the differential pinion gears, thrust washers and the locking differential spider into the case half.
7. Install the J 7872 - base and the J 8001 - indicator on the differential case.
Note: Preload the dial of the J 8001 - indicator approximately one turn clockwise.
8. Adjust the J 8001 - indicator on the tooth that is square to the differential side gear and set the J 8001 - indicator to zero
Note: In the following procedure, DO NOT unseat the locking differential spider. This will make the backlash reading inaccurate.
9. 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.
* Record the measurement.
Note: Measure the differential pinion gear to locking differential side gear backlash on the remaining differential pinion gears following the steps above.
10. 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).
Note:
* If the backlash is greater than, install a thicker differential side gear shim and recheck the backlash.
* If the backlash is less than, use a thinner differential side gear shim and recheck the backlash.
11. Differential side gear shims 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.
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. Tighten the bolt until the clutch plates are compressed.
Note: To perform the following measurement procedure, 2 of the J 34673 - Flat Gauge Bar will be needed.
10. Install the J 34673 - bar (2) and the J 34672 - micrometer (1) onto the differential case as shown.
11. Install the J 34673 onto the face of the differential case, not the ridge of the differential case, or an inaccurate measurement will result.
12. Using the J 34672 - micrometer and the J 34673 - bar , measure and record the depth from the face of the to the face of the differential side gear.
13. Measure the thickness of the J 34673 - bar subtract from the measurement obtained in step 10 and record the measurement. This measurement is equal to one-half of the thrust block thickness.
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.
17. Assemble a set of washers, a nut, and a bolt long enough in order to hold the side gear in place.
Note:
* The bolt must be long enough to hold the differential side gear in place and to allow the use of washers and nut.
* The washers must be the proper size in order to fit over the differential side gear, but without causing interference with the with the differential pinion gear and differential spider assembly.
* Tighten the nut and bolt just enough compress the clutch disc but will allow locking differential side gear to rotate.
18. Install the long bolt, washers and nut
19. Install the differential case half into a vise.
20. Clamp on the nut on the bottom of the differential case.
21. Install the J 34673 - bar (2) and the J 34672 - micrometer (1) onto the differential case.
22. Using the J 34673 - bar and the J 34672 - micrometer , measure and record the depth from the face of the to the face of the differential side gear.
Note: This measurement is equal to one-half of the thrust block thickness.
23. Measure the thickness of the J 34673 - bar subtract from the measurement obtained in step 23.
24. Add the measurements in step 12 and step 25 together. This is the thickness for the thrust block.
Note:
* If the measurement is equal to one of the thrust block sizes available, the select that thrust block.
* If the measurement is less than one of the thrust block sizes available, then select the next smaller thrust block.
25. Compare the measurement obtain in step 25 to the thrust block sizes available.
Note: The backlash must be rechecked and adjusted to specification anytime the left and/or the right thrust washers are replaced.
26. 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.
27. 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.
28. Recheck the left and/or right side gear backlash and adjust as necessary.
29. Recheck the thrust block clearance and adjust as necessary.