Pinion Depth Adjustment

Pinion Depth Adjustment

Tools Required
^ J34925 Pinion Setting Gage and Components
^ J8001 Dial Indicator Set

Important: Make sure all of the tools, the differential side bearing bores, and the pinion bearing cups are clean before proceeding.

1. Lubricate the pinion bearings with axle lubricant.
2. Install the pinion bearings into the axle housing.





3. Assemble the J21777-35 (1), the J21777-43 (2), the J21777-42 (3), and the J21777-29 (4) into the axle housing as shown.
4. While holding the J21777-43 stationary, install an inch-pound torque wrench on the nut of the J21777-43.
Tighten the nut on the J21777-43 until a rotating torque of 1.1 - 2.3 Nm (10 - 20 inch lbs.) is obtained.
5. Rotate the assembly several times in both directions in order to seat the pinion bearings.
6. Check the rotating torque of the assembly. If the torque is less than 1.1 Nm (10 inch lbs.), continue to tighten the nut on the J21777-43 until a rotating torque of 1.1 - 2.3 Nm (10 - 20 inch lbs.) is obtained.





7. Assemble the J21777-45 (1,2) to the J21777-1 (3) as shown.
8. Rotate the J21777-1 within the J21777-45. The J21777-1 must rotate back and forth freely within the discs. If the J21777-1 does not rotate freely, disassemble the components, inspect for proper seating and/or mix-aligned components and re-assemble.





9. Align the plunger of the J21777-1 (1) to the J21777-29 (2).
10. Install the J8001 to the J21777-1 as follows:
10.1. Loosely clamp the J8001 onto the stem on the J21777-1.
10.2. Place the contact pad of the J8001 onto the mounting post of the J21777-1.
10.3. With the contact pad of the J8001 touching the mounting post of the J21777-1, loosen the lock nut on the J8001 and push down on the J8001 until the needle the J8001 has turned 3/4 of a turn clockwise.
10.4. Tighten the clamp on the J8001 finger tight.
11. Move the plunger of the J21777-1 back and forth until the needle of the J8001 indicates the greatest deflection.
The deflection is the point where the needle changes direction.





12. At the greatest point of deflection, move the housing of the J8001 until the needle indicates ZERO.
13. Move the plunger of the J21777-1 back and forth again to verify the zero setting. Adjust the housing of the J8001 as necessary to set the needle to zero.
14. Rotate the plunger of the J21777-1 away from the J21777-29, until it no longer touches the J21777-29.
15. The value indicated on the J8001 is the thickness of the shim needed in order to set the depth of the pinion.
16. Select the shim that indicates the proper thickness. Measure the shim with a micrometer in order to verify that the thickness is correct.
17. Remove the pinion depth setting tools.
18. Remove the pinion bearings.
19. Install the pinion shim between the pinion gear and the inner pinion bearing. Refer to Drive Pinion Bearings Replacement.