Operation CHARM: Car repair manuals for everyone.

Rear Drive Axle

Drive Pinion Flange Yoke and/or Oil Seal Replacement

Tools Required
^ J8614-01 Flange/Pulley Holding Tool
^ J22388 Pinion Oil Seal Installer - Rear
^ J33782 Pinion Oil Seal Installer
^ J38694 Extension Housing Oil Pump/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 obtained prior to disassembly.

1. Raise the vehicle. Refer to Vehicle Lifting.
2. Remove the tire and wheel assemblies.
3. Remove the rear brake calipers.
4. Remove the brake rotors.





5. Disconnect the propeller shaft from the drive pinion yoke.
Position and secure the propeller shaft away from the rear axle.
6. 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

7. Record the measurement.





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





9. Install the J8614-01 as shown.
10. Remove the pinion nut while holding the J8614-0 1.
11. Remove the washer.





12. Install the J8614-2(2) and the J8614-3 (3) into the J8614-01 (1) as shown.
13. Remove the pinion yoke by turning the J8614-3 (3) clockwise while holding the J8614-01 (1).
Use a container in order to retrieve the lubricant.

Important: Do not damage the axle housing sealing surface.

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

Installation Procedure





1. Install the new pinion oil seal using one of the following:
^ For vehicles with a 7.6 inch axle, 2-Door Utilities and 4WD Pickups w/ RPO M50 and w/o RPO ZR2, use the J33782.
^ For 2-Door Utilities, use the J38694 (8.6 inch axle).

2. Apply sealant, GM P/N 12346004 (Canadian P/N 10953480) or equivalent, to the splines of the pinion flange/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 J8614-01 onto the pinion flange/yoke as shown.

Notice: Refer to Fastener Notice in Service Precautions.

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 J8614-01.
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 the 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.
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 to the drive pinion flange/yoke.
11. Install the brake rotors.
12. Install the brake calipers.
13. Install the tire and wheel assemblies.
14. Inspect and add axle lubricant to the axle housing, if necessary.
15. Lower the vehicle.