Tools Required

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 obtained 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 rear brake calipers (if equipped). Refer to Rear Brake Caliper Replacement in Disc Brakes.
4. Remove the brake rotors (if equipped). Refer to Rear Brake Rotor Replacement in Disc Brakes.
5. Remove the brake drums (if equipped).
6. Remove the propeller shaft. Refer to One-Piece Propeller Shaft Replacement or Two-Piece Propeller Shaft Replacement in Propeller Shaft.



7. On the 7.6 inch axle, determine the type of pinion oil seal used on the axle:

•	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.




8. Measure the amount of torque required to rotate the pinion using an inch-pound torque wrench. This will give the combined preload for the following components:

•	The pinion bearings

•	The pinion seal

•	The carrier bearings

•	The axle bearings

•	The axle seals

9. Record the measurement.



10. Draw an alignment mark between the pinion stem and the pinion flange/yoke.



11. Install the J 8614-01 as shown.
12. Remove the pinion nut while holding the J 8614-01 .
13. Remove the washer.



14. Install the J 8614-2 (2) and the J 8614-3 (3) into the J 8614-01  (1) as shown.
15. Remove the pinion yoke by turning the J 8614-3 (3) clockwise while holding the J 8614-01  (1).

Use a container in order to retrieve the lubricant.

Important: Do not damage the axle housing sealing surface.

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

Important: When replacing the pinion oil seal and/or the pinion yoke on the 7.6 inch axle, observe the following guidelines:

•	When replacing only the pinion oil seal, the same style pinion oil seal must be used.

•	If replacing both the pinion oil seal and the pinon yoke, the same style of the pinion oil seal and pinion yoke must be used.

•	The 2 lip and the 3 lip style pinion oil seals and pinion yokes are not interchangeable.

1. For the 7.6 inch axle, 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 .

For the 8.6 inch axle, install the new pinion oil seal using the J 22388 .

2. Apply sealant, GM P/N 12346004 or equivalent, to the splines of the pinion yoke.

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.

3. Install the pinion yoke.

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.

4. 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 flange/yoke.
5. Install the washer and a new pinion nut.



6. Install the J 8614-01 onto the pinion flange/yoke as shown.

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.

7. Tighten the pinion nut while holding the J 8614-01 .

Tighten
Tighten the nut until the pinion end play is removed. Rotate the pinion while tightening the nut to seat the bearings.




8. Measure the rotating torque of the pinion. Compare this measurement with the rotating torque recorded during removal.

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.

9. 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.
10. Install the propeller shaft. Refer to One-Piece Propeller Shaft Replacement or Two-Piece Propeller Shaft Replacement in Propeller Shaft.
11. Install the brake drums (if equipped).
12. Install the brake rotors (if equipped). Refer to Rear Brake Rotor Replacement in Disc Brakes.
13. Install the brake calipers (if equipped). Refer to Rear Brake Caliper Replacement in Disc Brakes.
14. Install the tire and wheel assemblies. Refer to Tire and Wheel Removal and Installation in Tires and Wheels.
15. Inspect and add axle lubricant to the axle housing, if necessary. Refer to Lubricant Level Check .
16. Lower the vehicle.