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10.5 Inch Axle

Locking Differential Adjustment (10.5 Inch Axle)

Tools Required
^ J7872 Magnetic Base Dial Indicator
^ J34672 Depth Micrometer
^ J34673 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 J7872 onto the differential case.
10. Loosely clamp the J8001-3 onto the stem of the J7872.
11. Place the contact pad of the J8001-3 on the tooth that is perpendicular to the differential side gear.
12. Preload the dial of the J8001-3 approximately 1 turn clockwise.
13. Tighten the lock nut on the J7872 finger tight.
14. Turn the dial of the J8001-3until 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:
15.1. Pull the pinion gear firmly into the seat.
15.2. 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.
15.3. 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 pinion gear and locking differential side gear should be between 0.279 - 0.432 mm (0.011 - 0.017 inch).
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:
Washer Sizes
^ 0.56 mm (0.022 inch)
^ 0.69 mm (0.027 inch)
^ 0.81 mm (0.032 inch)
^ 0.91 mm (0.036 inch)
^ 1.02 mm (0.040 inch)
^ 1.07 mm (0.042 inch)
^ 1.12 mm (0.044 inch)
^ 1.22 mm (0.048 inch)
^ 1.32 mm (0.052 inch)

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 year 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 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 J7872 onto the differential case.
11. Loosely clamp the J8001-3 onto the stem of the J7872.
12. Place the contact pad of the J8001-3 on the tooth that is perpendicular to the differential side gear.
13. Preload the dial of the J8001-3 approximately 1 turn clockwise.
14. Tighten the lock nut on the J7872 finger fight
15. Turn the dial of the J3001-.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 indicate,.
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 pinion gear and locking differential side gear should be between 0.051 - 0.203 mm (0.002 - 0.008 inch).
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: 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)

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 J34673 (2) and the J34672 (1) onto the differential case as shown.
8. Measure the depth from the face of the J34673 to the face of the differential side gear using the J34672.

Record the measurement.
9. Measure the thickness of the J34673.
10. Subtract the thickness of the J34673 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 J34673 and the J34673 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 J34673 (2) and the J34672 (1) onto the differential case as shown.
19. Measure the depth from the face of the J34673 to the face of the differential side gear using the J34672.

Record the measurement.





20. Measure the depth from the face of the J34673 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 inch), select the 40.89 mm (1.610 inch) 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 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.
26. If the measurement obtained in Step 22 is greater then 41.20 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.
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.