Drive Pinion Flange/Yoke and/or Oil Seal Replacement (8.6 Inch Axle W/Drum Brakes)

Drive Pinion Flange/Yoke and/or Oil Seal Replacement (8.6 Inch Axle w/Drum Brakes)
^ Tools Required
- J 8614-01 Flange/Pulley Holding Tool
- J 22388 Rear Axle Pinion Oil Seal Installer - Rear

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 and support the vehicle. Refer to Lifting and Jacking the Vehicle.
2. Reference mark the rear propeller shaft (3) to the rear axle pinion yoke (4).
3. Disconnect the propeller shaft from the axle. Wrap the bearing caps with tape in order to prevent the loss of bearing rollers. Support the propeller shaft as necessary.





4. Using an inch-pound torque wrench, measure the amount of torque required to rotate the pinion. 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





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





6. Install the J 8614-01 as shown.
7. While holding the J 8614-01, loosen the pinion nut.
8. Remove the washer.





9. Remove the pinion nut and washer.





10. Install the J 8614-2 (2) and the J 8614-3 (3) into the J 8614-01 (1) as shown.
11. 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.





12. Remove the pinion oil seal. Use a suitable seal removal tool. Do not damage the housing.

Installation Procedure





1. Install a new pinion oil seal using the J 22388.





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.

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.

Notice: Refer to Pinion Flange/Yoke Installation Notice in Service Precautions.

5. Install the washer and a NEW pinion nut.





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

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.






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. Recheck the rotating torque and adjust if necessary.





10. Install the propeller shaft (3) to the pinion yoke (4). Align the reference marks made during removal.
11. Install the propeller shaft yoke retaining clamps and the bolts.
^ Tighten the bolts to 25 Nm (18 ft. lbs.).
12. Inspect and add axle lubricant to the axle housing, if necessary.
13. Lower the vehicle.