Bearing Turning Torque Measurement

To determine proper select shim thickness for the Differential and driven transfer gear bearings, the turning torque must be measured.

If the bearings, differential, driven transfer gear or transaxle housings have been replaced turning torque of the differential (1) and then turning torque with the transfer gear (2) added must be performed. A good starting point to would be to use the factory installed select shims behind the bearing races in the transaxle housing and bell housing.

Verify that the bearings and races are NEW  and properly installed on/in clean components with the factory installed select shims behind the bearing races. Lightly lubricate the bearings with transaxle fluid.

Tool (special tool #C-4995A, Tool, Differential Bearing Torque) must be modified to be compatibly with the following operation. Two 3/8-24 nuts (1) must be added to keep the center shaft from rotating in the cone and sleeve.

1. Remove the nylok™ nut and expander cone from the center shaft.
2. Remove the sleeve from the center shaft.
3. Install a nut on the center shaft and tighten it against the existing nut. Install the sleeve.
4. Install the 2nd nut inside the sleeve just far enough to install the cone and nut.
5. Install the cone and nut tight enough to keep the center shaft from rotating inside the cone and sleeve.

MEASUREMENT PROCEDURE 

1. Position the differential on a clean work surface.
   Fig 3: Differential Pinion Gears & Lock Tool

   Courtesy of CHRYSLER GROUP, LLC
2. Install the lock tool (special tool #10425, Tool, Pinion and Side Gear Locking) (2) between the differential (1) pinion gears next to the link pin to prevent the differential from rotating.
3. Position the transaxle and bell housings on a suitable clean work bench.
4. Install new bearing races with the original select shims.
5. Install the differential with new bearings lightly lubricated with transaxle fluid in the transaxle housing.
6. Install the bell housing.
7. Install the bolts to hold the bell housing to the transaxle housing. Tighten bolts to 50% on the specified torque value. Refer to SPECIFICATIONS .
8. Insert modified tool (special tool #C-4995A, Tool, Differential Bearing Torque) into the differential until the sleeve (C-4995-1) enters the halfshaft spline in the differential side gear.
9. Tighten the nut until the sleeve expands tightly in the side gear.
10. Tighten the jamb nut to prevent the center shaft from rotating in the sleeve.
11. Using a suitable wrench, rotate the differential 20 rotations clockwise and 20 rotations counterclockwise.
    Fig 4: Torque Wrench & Differential

    Courtesy of CHRYSLER GROUP, LLC
12. Using a torque wrench (1), measure the turning resistance of the differential (2) after the initial break away. Refer to SPECIFICATIONS .
13. Adjust the turning torque by adding to or subtracting from the thickness of the select shims behind the differential bearing races.
14. After achieving proper differential turning torque, separate the bell housing from the transaxle housing.
    Fig 5: Differential & Transfer Gear

    Courtesy of CHRYSLER GROUP, LLC
15. Install the driven transfer gear (2) with new bearings into the transaxle housing.
16. Install the bell housing.
17. Install the bolts to hold the bell housing to the transaxle housing. Tighten bolts to 50% on the specified torque value. Refer to SPECIFICATIONS .
    NOTE:

    The turning torque of the differential and the transfer gear will be about 4 times higher than the differential alone. The ring gear is driving a much smaller pinion gear on the transfer shaft.

18. Using a suitable wrench, rotate the differential 20 rotations clockwise and 20 rotations counterclockwise.
19. Using a torque wrench (1), measure the turning resistance of the differential (2) after the initial break away. Refer to SPECIFICATIONS .
20. Adjust the turning torque by adding to or subtracting from the thickness of the select shims behind the driven transfer shaft bearing races.
21. Remove tool C-4995 from the differential.
22. Separate the bell housing from the transaxle housing.
    Fig 6: Differential & Transfer Gear

    Courtesy of CHRYSLER GROUP, LLC
23. Remove the differential (1) and driven transfer gear (2).
    Fig 7: Differential Pinion Gears & Lock Tool

    Courtesy of CHRYSLER GROUP, LLC
24. Remove lock tool 10425 (2) from the differential (1).
25. Prepare transaxle components for final assembly.