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 made prior to disassembly.

1. Raise the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
2. Remove the propeller shaft. Refer to One-Piece Propeller Shaft Replacement or Two-Piece Propeller Shaft Replacement in Propeller Shaft.



3. 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.




4. Measure the amount of torque required to rotate the pinion using an inch-pound torque wrench.
5. Record the measurement.



6. In order to maintain the correct drive pinion gear and pinion flange/yoke relationship, mark the position of the following components before disassembly:

•	The drive pinion gear flange/yoke (1)

•	The drive pinion gear shaft

7. Place a drain pan under the rear axle pinion flange/yoke.
8. Install the J 8614-01 to the pinion flange.
9. Using the J 8614-01 in order to hold the pinion flange stationary, remove the following components:

•	The drive pinion gear nut

•	The drive pinion gear washer




10. With the J 8614-01 still installed to the pinion flange, use the forcing screw in order to remove the drive pinion gear flange/yoke (1).




Important: Do not damage the rear axle housing when removing the drive pinion gear seal.

11. Use a blunt chisel in order to drive the drive pinion gear seal out of the rear axle housing.
12. Inspect the sealing surface of the drive pinion flange/yoke for the following conditions:

•	Tool marks

•

Nicks

•	Grooves from the drive pinion oil seal

13. If the drive pinion gear flange/yoke is damaged or grooved, replace the drive pinion gear flange/yoke.
14. Inspect the housing bore for burrs.

Remove any burrs that might cause leaks around the outer diameter (OD) of the drive pinion gear seal.

Important: When replacing the pinion oil seal and/or the pinion flange/yoke, observe the following guidelines:

•	When replacing only the pinion oil seal, the same style pinion oil seal must be used as the one that was removed.

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

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

1. 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 .
2. Apply sealant, GM P/N 12346004 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. Align the reference mark on the pinion flange/yoke to the pinion gear shaft and install the drive pinion gear flange/yoke.
4. Install the following components:

•	The drive pinion gear washer

•	The new drive pinion gear nut

5. Hand tighten the drive pinion gear nut.

Notice: Refer to Fastener Notice in the Preface section.





Important: Do not exceed the rotating torque specification. If the rotating torque specification is exceeded, the collapsible spacer must be replaced.

6. Using the J 8614-01 in order to hold the drive pinion gear flange/yoke (1) stationary, tighten the pinion gear nut until the pinion end play is removed.
7. Tighten the drive pinion gear nut in small increments while measuring the rotating torque of the pinion.

Tighten
Tighten the drive pinion gear nut until the rotating torque is 0.40-0.57 N·m (3-5 lb in) greater than the rotating torque recorded during removal.

8. Remove the tool.
9. Install the propeller shaft. Refer to One-Piece Propeller Shaft Replacement or Two-Piece Propeller Shaft Replacement in Propeller Shaft.
10. Inspect the rear axle lubricant level. Refer to Lubricant Level Check .
11. Lower the vehicle.