Drive Pinion Flange/Yoke and/or Oil Seal Replacement 8.6, 9.5, 10.5 Inch Axle

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. 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 Lifting and Jacking the Vehicle in General Information.
2. Remove the tire and wheel assemblies (8.6 inch, 9.5 inch axles). Refer to Tire and Wheel Removal and Installation in Tires and Wheels.
3. Remove the rear brake drums (8.6 inch, 9.5 inch axles). Refer to Brake Drum Replacement in Drum Brakes.
4. Remove the axle shafts (10.5 inch axle). Refer to Rear Axle Shaft and/or Gasket Replacement .
5. Disconnect the propeller shaft from the rear axle. Refer to One-Piece Propeller Shaft Replacement or Two-Piece Propeller Shaft Replacement in Propeller Shaft.



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, 8.6 and 9.5 inch axles

•	The axle seals, 8.6 and 9.5 inch axles




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



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



11. Install the J 8614-2 (2) and the J 8614-3 (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 housing.

1. Install a new seal using the J 22388 (8.6 inch, 9.5 inch axle) or the J 44414 (10.5 inch axle).
2. Apply sealant (GM P/N 12346004 or equivalent) to the splines of the pinion yoke.



3. Install the pinion yoke.

Align the marks made during removal.

Notice: Refer to Pinion Flange/Yoke Installation Notice in the Preface section.

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 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 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
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. Recheck the rotating torque and adjust if necessary.
10. Install the propeller shaft to the rear axle pinion yoke or to the yoke flange. Refer to One-Piece Propeller Shaft Replacement or Two-Piece Propeller Shaft Replacement in Propeller Shaft.
11. Install the axle shafts (10.5 inch axle). Refer to Rear Axle Shaft and/or Gasket Replacement .
12. Install the brake drums (8.6 inch, 9.5 inch axles). Refer to Brake Drum Replacement in Drum Brakes.
13. Install the tire and the wheel (8.6 inch, 9.5 inch axles). Refer to Tire and Wheel Removal and Installation in Tires and Wheels.
14. Inspect and add axle lubricant to the axle housing, if necessary. Refer to Lubricant Level Check .
15. Lower the vehicle.