SMU - Revised Drive Pinion Flange/Yoke and/or Oil Seal Replacement Procedure

This bulletin is being revised to correct the model and model year information and to update tool information. Please discard Corporate Bulletin Number 01-04-20-004 (Section 04 - Driveline/Axle).

This bulletin is being issued to revise the Drive Pinion Flange/Yoke and/or Oil Seal Replacement procedure in the Rear Drive Axle sub-section of the above Service Manuals.

The following information has been updated within SI. If you are using a paper version of the Service Manual, please make a reference to this bulletin on the affected page.

Important: Tool J 8614-01 has been renamed to J 08614-A and tool J 23911 has been renamed to J 23911-A. If using tool J 23911-A, tool J 5590 will also need to be used.

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 (SI Document ID #710253).
2. Remove the tire and wheel assemblies. Refer to Tire and Wheel Removal and Installation in Tires and Wheels (SI Document ID #539493).
3. Remove the brake drums.
4. Remove the propeller shaft. Refer to Propeller Shaft Replacement - Rear in Propeller Shaft (SI Document ID #376875).



5. Determine the type of pinion oil seal that is used on the axle.

On early production axles, a 2 lip pinion seal was used. The seal can be identified by the short deflector (1) used on the pinion yoke/flange.

On late production axles, a 3 lip pinion seal was used. The seal can be identified by the long deflector (2) used on the pinion yoke/flange.




6. Measure the amount of torque required to rotate the pinion. Use 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 J 08614-1 as shown.
10. Remove the pinion nut while holding the J 08614-1.
11. Remove the washer.



12. Install the J 08614-2 (2) and the J 08614-3 (3) into the J 08614-1 (1) as shown.
13. Remove the pinion yoke by turning the J 08614-3 (3) clockwise while holding the J 08614-01.

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.

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 or the J 23911-A and the J 5590. For the 3 lip style pinion oil seal, use the J 33782.
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 flange/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 yoke.
5. Install the washer and a new pinion nut.



6. Install the J 08614-1 onto the pinion flange/yoke as shown.

Notice: Refer to Fastener Notice in Cautions and Notices.

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 08614-1.

Tighten
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
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. Check the rotating torque and adjust if necessary.
10. Install the propeller shaft. Refer to Propeller Shaft Replacement - Rear in Propeller Shaft (SI Document ID #376875).
11. Install the brake drums.
12. Install the tire and wheel assemblies. Refer to Tire and Wheel Removal and Installation in Tires and Wheels (SI Document ID #539493).
13. Inspect and add axle lubricant to the axle housing, if necessary. Refer to Lubricant Level Check in Rear Drive Axle (SI Document ID #711724).
14. Lower the vehicle.

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 obtained prior to disassembly.

1. Raise the vehicle. Refer to Lifting and Jacking the Vehicle in General Information (SI Document ID #672691).
2. Remove the tire and wheel assemblies. Refer to Tire and Wheel Removal and Installation in Tires and Wheels (SI Document ID #539493).
3. Remove the rear brake calipers (if equipped). Refer to Brake Caliper Replacement - Rear in Disc Brakes (SI Document ID #526299).
4. Remove the brake rotors (if equipped). Refer to Brake Rotor Replacement - Rear in Disc Brakes (SI Document ID #724629).
5. Remove the brake drums (if equipped).
6. Remove the propeller shaft. Refer to Propeller Shaft Replacement - One Piece (SI Document ID #678184) or Propeller Shaft Replacement - Two Piece (SI Document ID #678187) in Propeller Shaft.



7. On the 7.6 inch axle, determine the type of pinion oil seal that is used on the axle.

On early production axles, a 2 lip pinion seal was used. The seal can be identified by the short deflector (1) used on the pinion yoke/flange.

On late production axles, a 3 lip pinion seal was used. The seal can be identified by the long deflector (2) used on the pinion yoke/flange.




8. 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

9. Record the measurement.



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



11. Install the J 08614-1 as shown.
12. Remove the pinion nut while holding the J 08614-1.
13. Remove the washer.



14. Install the J 08614-2 (2) and the J 08614-3 (3) into the J 08614-1  (1) as shown.
15. Remove the pinion yoke by turning the J 08614-3 (3) clockwise while holding the J 08614-1 (1).

Use a container in order to retrieve the lubricant.

Important: Do not damage the axle housing sealing surface.

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

Important: When replacing the pinion oil seal and/or the pinion yoke on the 7.6 inch axle, observe the following guidelines:

•	When replacing only the pinion oil seal, the same style pinion oil seal must be used.

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

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

1. For the 7.6 inch axle, install the new pinion gear oil seal. For the 2 lip style pinion oil seal, use the J 23911 or the J 23911-A and the J 5590. For the 3 lip style pinion oil seal, use the J 33782. For the 8.6 inch axle, install the 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.

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 J 08614-1 onto the pinion flange/yoke as shown.

Notice: Refer to Fastener Notice in Cautions and Notices.

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 08614-1.

Tighten
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
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. Check the rotating torque and adjust if necessary.
10. Install the propeller shaft. Refer to Propeller Shaft Replacement - One Piece (SI Document ID #678184) or Propeller Shaft Replacement - Two Piece (SI Document ID #678187) in Propeller Shaft.
11. Install the brake drums (if equipped).
12. Install the brake rotors (if equipped). Refer to Brake Rotor Replacement - Rear in Disc Brakes (SI Document ID #724629).
13. Install the brake calipers (if equipped). Refer to Brake Caliper Replacement - Rear in Disc Brakes (SI Document ID #526299).
14. Install the tire and wheel assemblies. Refer to Tire and Wheel Removal and Installation in Tires and Wheels (SI Document ID #539493).
15. Inspect and add axle lubricant to the axle housing, if necessary. Refer to Lubricant Level Check in Rear Drive Axle (SI Document ID #718210).
16. Lower the vehicle.