Pinion Seal

REMOVAL & INSTALLATION

NOTE: A new companion flange nut is needed before removal. The old nut cannot be used.

1. Raise and safely support the rear of the vehicle securely on jackstands.

   Fig. 1: The oil seal in the rear differential is located behind the companion flange

2. Disconnect the rear driveshaft. Make sure matchmarks are made for installation.
3. Using a chisel and hammer, loosen the staked part of the nut on the companion flange. With a retaining too, hold the flange and remove the nut and plate washer. Using a screw type puller, remove the companion flange.
4. With a seal puller, remove the oil seal and slinger.

   Fig. 2: Stake the nut, then retain the flange and remove the nut

   Fig. 3: Use a screw type puller and remove the companion flange . . .

   Fig. 4: . . . then extract the oil seal using a puller

   To install:

5. Insert the new oil slinger, then apply MP grease on the new oil seal and drive it into the housing. Drive depth is approximately 0.0059 inches (1.5mm).

   Fig. 5: Drive a new oil seal into the differential lubricated with MP grease

6. With the screw type puller, install the companion flange on the drive pinion. Place the plate washer on the companion flange.
   1. Apply a light coat of gear oil on the threads of a new companion flange nut. Retain the flange and tighten the nut to 80 ft. lbs. (108 Nm).
7. Adjust the drive pinion preload as follows:
   1. Using a torque meter, measure the preload of the backlash between the drive pinion and ring gear.
      • New bearing — 10.4–16.5 inch lbs. (1.2–1.9 Nm)
      • Reused bearing — 5.2–8.7 inch lbs. (0.6–1.0 Nm)
   2. If the preload is greater than specification, replace the bearing spacer.
   3. If the preload is less than specification, retighten the nut to 9 ft. lbs. (13 Nm) a little at a time until the specified preload is reached.

      Fig. 6: Use a torque meter to measure the preload of the backlash between the drive pinion and ring gear

8. If the maximum torque is exceeded while retightening the nut, replace the bearing spacer and repeat the preload procedure. Do not back-off the pinion nut to reduce preload. Maximum torque is 174 ft. lbs. (235 Nm).
9. Stake the drive pinion nut.
10. Connect the rear driveshaft.
11. Check and top-off the differential fluid level.
12. Lower the rear of the vehicle and test drive the vehicle.