Pinion Flange: Service and Repair

Drive Pinion Flange/Yoke and/or Oil Seal Replacement

^ Tools Required
- J 8614-01 Flange and Pulley Holding Tool
- J 38694 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. Reassemble all the components in the exact places in which you removed the parts. Follow any specifications, torque values, and any measurements made prior to disassembly.

1. Raise the vehicle. Refer to Vehicle Lifting.
2. Remove the tire and wheel assemblies.
3. Remove the brake calipers.
4. Remove the brake rotors.
5. Disconnect the propeller shaft from the pinion yoke and support as necessary.





6. Measure the amount of torque required to rotate the pinion. Use an inch-pound torque wrench. Record this measurement for reassembly. This will give the combined preload for the following components:
^ The pinion bearings
^ The pinion oil seal
^ The differential case bearings
^ The axle bearings
^ The axle seals





7. Place an alignment mark between the pinion and the pinion yoke.





8. Install the J8614-01 as shown.
9. Remove the pinion nut while holding the J 8614-01.
10. Remove the washer.





11. Install the J 8614-3 (2) and the J 8614-2 (3) into the J 8614-01 (1) as shown.
12. 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.
13. Remove the pinion oil seal. Use a suitable seal removal tool. Do not damage the axle housing.

Installation Procedure





1. Install a new pinion oil seal using the J38694.
2. Apply sealant GM P/N 12346004 (Canadian P/N 10953480) or equivalent to the splines of the pinion yoke.





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





6. Install the J 8614-01 onto the pinion 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 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.





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 (35 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. Recheck the rotating torque and adjust if necessary.
10. Install the propeller shaft.
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.