GM Service Manual Online
For 1990-2009 cars only

Tools Required

    • J 8614-01 Pinion Flange Holder
    • J 23911 Pinion Oil Seal Installer
    • J 33782 Pinion Oil Seal Installer

Removal Procedure

    Important: Observe and mark the positions of all the driveline components relative to the propeller shaft and the axles prior to disassembly. These components include the propeller shafts, drive axles, pinion flanges, output shafts, etc. Assemble all the components in the exact places in which you removed the parts. Follow any specifications, torque values, and measurements made prior to disassembly.

  1. Raise the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
  2. Remove the tire and wheel assemblies. Refer to Tire and Wheel Removal and Installation in Tires and Wheels.
  3. Remove the brake drums.
  4. Remove the propeller shaft. Refer to Rear Propeller Shaft Replacement in Propeller Shaft.

  5. Object Number: 791776  Size: MH
  6. Determine the type of pinion oil seal used:
  7. • 2 lip pinion seal -- This seal type can be identified by the short deflector (1) used on the pinion yoke/flange.
    • 3 lip pinion seal -- This seal type can be identified by the long deflector (2) used on the pinion yoke/flange.

    Object Number: 661077  Size: SH
  8. Measure the amount of torque required to rotate the pinion. Use an inch-pound torque wrench. This will give the combined preload for the following components:
  9. • The pinion bearings
    • The pinion seal
    • The carrier bearings
    • The axle bearings
    • The axle seals
  10. Record the measurement.

  11. Object Number: 788905  Size: SH
  12. Draw an alignment mark between the pinion stem and the pinion flange/yoke.

  13. Object Number: 661080  Size: SH
  14. Install the J 8614-01 as shown.
  15. Remove the pinion nut while holding the J 8614-01 .
  16. Remove the washer.

  17. Object Number: 661074  Size: SH
  18. Install the J 8614-2 (2) and the J 8614-3 (3) into the J 8614-01  (1) as shown.
  19. Remove the pinion yoke by turning the J 8614-3 (3) clockwise while holding the J 8614-01  (1).
  20. Use a container in order to retrieve the lubricant.

    Important: Do not damage the axle housing sealing surface.

  21. Remove the pinion oil seal using a suitable seal removal tool.

Installation Procedure


    Object Number: 651744  Size: SH

    Important: When replacing the pinion oil seal and/or the pinion flange/yoke, observe the following guidelines:

       • When replacing only the pinion oil seal, the same style pinion oil seal must be used as the one that was removed.
       • If replacing both the pinion oil seal and the pinion flange/yoke, the same style of pinion oil seal and the pinion flange/yoke must be used.
       • The 2 lip and the 3 lip style pinion oil seals and pinion flange/yokes are not interchangeable.

  1. Install the new pinion gear oil seal. For the 2 lip style pinion oil seal, use the J 23911 . For the 3 lip style pinion oil seal, use the J 33782 .
  2. Apply sealant, GM P/N 12346004 or equivalent, to the splines of the pinion flange/yoke.
  3. Important: Install the pinion gear flange/yoke to the pinion gear shaft in the same position as marked during removal in order to maintain correct driveline balance.

  4. Install the pinion flange/yoke.
  5. Align the marks made during removal.

    Notice: Do not hammer the pinion flange/yoke onto the pinion shaft. Pinion components may be damaged if the pinion flange/yoke is hammered onto the pinion shaft.

  6. Seat the pinion flange/yoke onto the pinion shaft by tapping it with a soft-faced hammer until a few pinion shaft threads show through the yoke.
  7. Install the washer and a new pinion nut.

  8. Object Number: 661080  Size: SH
  9. Install the J 8614-01 onto the pinion flange/yoke as shown.
  10. Notice: Refer to Fastener Notice in the Preface section.

    Important: If the rotating torque is exceeded, the pinion will have to be removed and a new collapsible spacer installed.

  11. Tighten the pinion nut while holding the J 8614-01 .
  12. Tighten
    Tighten the nut until the pinion end play is removed. Rotate the pinion while tightening the nut to seat the bearings.


    Object Number: 661077  Size: SH
  13. Measure the rotating torque of the pinion. Compare this measurement with the rotating torque recorded during removal.
  14. Tighten
    Tighten the nut in small increments, as needed, until the rotating torque is 0.40-0.57 N·m (3-5 lb in) greater than the rotating torque recorded during removal.

  15. Once the specified torque is obtained, rotate the pinion several times to ensure the bearings have seated. Check the rotating torque and adjust if necessary.
  16. Install the propeller shaft. Refer to Rear Propeller Shaft Replacement in Propeller Shaft.
  17. Install the brake drums.
  18. Install the tire and wheel assemblies. Refer to Tire and Wheel Removal and Installation in Tires and Wheels.
  19. Inspect and add axle lubricant to the axle housing, if necessary. Refer to Lubricant Level Check .
  20. Lower the vehicle.