Pinion Depth Adjustment

Special Tools

• J 29763  Static Timing Gauge
• J 33838  Pinion Setting Gauge

For equivalent regional tools, refer to Special Tools .

NOTE:

Make sure all of the tools, the pinion bearings, and the pinion bearing cups are clean before proceeding.

1. Lubricate the pinion bearings with axle lubricant. Refer to Fluid and Lubricant Recommendations .
2. Install the J 33838-2 (1) and the bolt (2) to the outer pinion bearing.
Fig 1: J 33838-2 & Bolt To Outer Pinion Bearing
Courtesy of GENERAL MOTORS COMPANY
3. Install the J 33838-2 (1) and the bolt (2) with the outer pinion bearing into the differential carrier assembly case half.
Fig 2: Inner Pinion Bearing Onto J 33838
Courtesy of GENERAL MOTORS COMPANY
4. Install the inner pinion bearing onto the J 33838  gauge as shown.
Fig 3: J 33838 With Inner Pinion Bearing Into Differential Carrier Assembly
Courtesy of GENERAL MOTORS COMPANY
5. Install the J 33838  gauge (2) with the inner pinion bearing into the differential carrier assembly and the bolt (1).
6. While holding the J 33838  gauge stationary, install an inch-pound torque wrench on the bolt of the J 33838  gauge and tighten the bolt.

   Tighten 

   Tighten the bolt until a rotating torque of 1.7-3.4 (15-30 lb in) for new bearings or 1.0-2.3 (10-20 lb in) for used bearings is obtained.

7. Rotate the assembly several times in both directions in order to seat the pinion bearings.
8. Check the rotating torque of the assembly. If the torque is less than 1.7 (15 lb in) for new bearings or 1.0 (10 lb in) for used bearings, continue to tighten the bolt until a rotating torque of 1.7-3.4 (15-30 lb in) for new bearings or 1.0-2.3 (10-20 lb in) for used bearings is obtained.
9. Place the contact pad of the J 33838  gauge into the differential side bearing bore.
10. Install the J 29763  gauge to the J 33838  gauge by doing the following:
    1. Install the collar and the lock nut onto the J 33838  gauge.

       Do not tighten the lock nut at this time.

    2. Install the J 29763  gauge into the collar.
    3. Place the stem of the J 29763  gauge onto the contact surface of the J 33838  gauge.
    4. With the stem of the J 29763  gauge touching the contact surface of the J 33838  gauge , push down on the J 29763  gauge until the needle of the J 29763  gauge has turned 3/4 of a turn clockwise.
    5. Tighten the lock nut of the J 29763  gauge finger tight.
11. Rotate the J 33838  gauge back and forth until the needle of the J 29763  gauge indicates the lowest point in the differential side bearing bore.
Fig 4: Dial Indicator Installed In Differential Carrier
Courtesy of GENERAL MOTORS COMPANY
12. At the lowest point of deflection, move the housing of the J 29763  gauge (2) until the needle indicates ZERO.
13. Move the J 33838  gauge (1) back and forth again to verify the ZERO setting. Adjust the housing of the J 29763  gauge (2) as necessary to set the needle to ZERO.
Fig 5: Shim Thickness Indicated On Gauge
Courtesy of GENERAL MOTORS COMPANY
14. After the ZERO setting is obtained and verified, grasp the J 33838  gauge (1) by the flats and move the contact pad of the J 33838  gauge out of the differential side bearing bore.
15. The value indicated on the J 29763  gauge (2) 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 from the pinion depth setting tools.
19. Assemble the differential carrier assembly. Refer to Differential Carrier Assembly Assemble .