Pinion Depth Adjustment

Tools Required 

• J-33838  Pinion Setting Gage
• J-29763  Static Timing Gage

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.
2. Install the J-33838-2 (1) and the bolt (2) to the outer pinion bearing.
3. Install the J-33838-2 (1) and the bolt (2) with the outer pinion bearing into the differential carrier assembly case half.
   Fig 1: Installing J-33838-2 & Bolt To Outer Pinion Bearing

   Courtesy of GENERAL MOTORS CORP.
4. Install the inner pinion bearing onto the J-33838  as shown.
   Fig 2: Installing Inner Pinion Bearing Onto J-33838

   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).
6. While holding the J-33838  stationary, install an inch-pound torque wrench on the bolt of the J-33838  and tighten the bolt.

   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.
   Fig 3: Installing J-33838 With Inner Pinion Bearing Into Differential Carrier Assembly & Bolt

   Courtesy of GENERAL MOTORS CORP.
10. Install the J-29763  to the J-33838  by doing the following:
    1. Install the collar and the lock nut onto the J-33838  .

       Do not tighten the lock nut at this time.

    2. Install the J-29763  into the collar.
    3. Place the stem of the J-29763  onto the contact surface of the J-33838  .
    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.
    5. Tighten the lock nut of the J-29763  finger tight.
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.
12. At the lowest point of deflection, move the housing of the J-29763  until the needle indicates ZERO.
13. Move the J-33838  back and forth again to verify the ZERO setting. Adjust the housing of the J-29763  as necessary to set the needle to ZERO.
    Fig 4: Installing J-29763 To J-33838

    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.
15. The value indicated on the J-29763  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 .
    Fig 5: Removing J-33838 Out Of Differential Side Bearing Bore

    Courtesy of GENERAL MOTORS CORP.