Pinion Flange Replacement

Removal Procedure
^ Tools Required
- J 8614-01 Pinion Flange Holder

Important: Note the positions and accurately reference mark all driveline components relative to the disassembly of the propeller shaft and axles. These components include the propeller shafts, drive axles, pinion yokes and output shafts. The published specifications and torque values, as well as any measurements made prior to disassembly must also be followed. All components must be reassembled in the exact relationship to each other as when removed.

1. In order to free the steering linkage for movement, unlock the steering column.
2. Raise the vehicle. Refer to Vehicle Lifting.
3. Remove the front wheels. Refer to Tire and Wheel Removal and Installation in Steering and Suspension.
4. Remove the front rotors. Refer to Brake Rotor Replacement in Brakes and Traction Control.
5. Remove the front propeller shaft. Refer to Propeller Shaft Replacement - Front.





6. Measure the amount of torque required to rotate the pinion. Use an inch-pound torque wrench. Record this measurement for reassembly. This will provide the combined preload for the following components:
^ The pinion bearings
^ The pinion seal
^ The carrier bearings
^ The axle bearings
^ The axle seals
^ The wheel drive shafts
^ The wheel bearings
7. Draw an alignment mark between the pinion shaft and the pinion flange.
8. Record the number of exposed threads on the pinion shaft for reference.





9. Remove the pinion flange nut and washer, using J 8614-01 in order to secure the flange.





10. Remove the pinion flange using J8614-01.
Provide a suitable container to catch the lubricant.

Installation Procedure





1. Apply sealant (GM P/N 12346004 or equivalent) to the inside sealing surface of the pinion flange.
2. Apply special seal lubricant (GM P/N 12377985 or equivalent) to the outside sealing surface of the pinion flange and the sealing lip of the seal.

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.

Important: Install the pinion flange in the same position as marked during removal to maintain driveline balance.

3. Install the pinion flange by tapping it with a soft-faced hammer until a few pinion shaft threads show through the flange.

Notice: Refer to Fastener Notice in Service Precautions.

Important: Reference the number of exposed threads on the pinion shaft recorded during removal.

4. Install the washer and a new nut using J 8614-01.
^ Tighten the nut until the pinion end play is just taken up. Rotate the pinion while tightening the nut to seat the bearings.





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

5. Measure the torque required to rotate the pinion using an inch-pound torque wrench. Compare this value with the torque recorded during removal.
^ Tighten the pinion shaft nut in small increments, as needed, until the rotating torque is 0.40 - 0.57 Nm (3 - 5 inch lbs.) greater than the rotating torque recorded during removal.
6. Once the specified torque is obtained, rotate the pinion several times to ensure the bearings have seated. Recheck the rotating torque and adjust if necessary.
7. Install the propeller shaft. Refer to Propeller Shaft Replacement - Front. Align the marks made during removal. Components must be reassembled in the same position.
8. Inspect the axle lubricant level. Add lubricant as necessary. Refer to Fluid and Lubricant Recommendations.
9. Install the front rotors. Refer to Brake Rotor Replacement in Brakes and Traction Control.
10. Install the front wheels. Refer to Tire and Wheel Removal and Installation in Steering and Suspension.
11. Lower the vehicle.