Pinion Depth Adjustment

Tools Required

• J 33838  Pinion Setting Gage. See Special Tools and Equipment .
• J 29763  Static Timing Gage. See Special Tools and Equipment .

IMPORTANT: 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 in Maintenance and Lubrication.
2. Install the J 33838-2  (1) and the bolt (2) to the outer pinion bearing.
Fig 1: Installing J 33838-2 With Outer Pinion Bearing Into Differential Carrier Assembly Case Half
Courtesy of GENERAL MOTORS CORP.
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: Installing Inner Pinion Bearing Into J 33838
Courtesy of GENERAL MOTORS CORP.
4. Install the inner pinion bearing onto the J 33838  as shown. See Special Tools and Equipment .
Fig 3: Installing J 33838 Into Differential Carrier Assembly
Courtesy of GENERAL MOTORS CORP.
5. Install the J 33838  (2) with the inner pinion bearing into the differential carrier assembly and the bolt (1). See Special Tools and Equipment .
6. While holding the J 33838  stationary, install an inch-pound torque wrench on the bolt of the. See Special Tools and Equipment .J 33838  and tighten the bolt. See Special Tools and Equipment .

   Tighten:  Tighten the bolt until a rotating torque of 1.7-3.4 N.m (15-30 lb in) for new bearings or 1.0-2.3 N.m (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 N.m (15 lb in) for new bearings or 1.0 N.m (10 lb in) for used bearings, continue to tighten the bolt until a rotating torque of 1.7-3.4 N.m (15-30 lb in) for new bearings or 1.0-2.3 N.m (10-20 lb in) for used bearings is obtained.
9. Place the contact pad of the J 33838  into the differential side bearing bore. See Special Tools and Equipment .
10. Install the J 29763  to the J 33838  by doing the following. See Special Tools and Equipment .
    1. Install the collar and the lock nut onto the J 33838  . See Special Tools and Equipment .

       Do not tighten the lock nut at this time.

    2. Install the J 29763  into the collar. See Special Tools and Equipment .
    3. Place the stem of the J 29763  onto the contact surface of the J 33838  . See Special Tools and Equipment .
    4. With the stem of the J 29763  touching the contact surface of the J 33838  , push down on the J 29763  until the needle of the J 29763  has turned 3/4 of a turn clockwise. See Special Tools and Equipment .
    5. Tighten the lock nut of the J 29763  finger tight. See Special Tools and Equipment .
11. Rotate the J 33838  back and forth until the needle of the J 29763  indicates the lowest point in the differential side bearing bore. See Special Tools and Equipment .
Fig 4: Setting Dial Indicator
Courtesy of GENERAL MOTORS CORP.
12. At the lowest point of deflection, move the housing of the J 29763  until the needle indicates ZERO. See Special Tools and Equipment .
13. Move the J 33838  back and forth again to verify the ZERO setting. See Special Tools and Equipment . Adjust the housing of the J 29763  as necessary to set the needle to ZERO. See Special Tools and Equipment .
Fig 5: Determining Shim Thickness
Courtesy of GENERAL MOTORS CORP.
14. After the ZERO setting is obtained and verified, grasp the J 33838  by the flats and move the contact pad of the J 33838  out of the differential side bearing bore. See Special Tools and Equipment .
15. The value indicated on the J 29763  is the thickness of the shim needed in order to set the depth of the pinion. See Special Tools and Equipment .
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  .