GM Full-Size Trucks 1988-1998 Repair Information

Pinion Seal

Print

REMOVAL & INSTALLATION



See Figures 1, 2, 3 and 4

  1. Raise and support the front end on jackstands.
  2.  



Click image to see an enlarged view

Fig. Fig. 1: Measuring the pinion rotating torque



Click image to see an enlarged view

Fig. Fig. 2: Scribed marks



Click image to see an enlarged view

Fig. Fig. 3: Removing the pinion nut



Click image to see an enlarged view

Fig. Fig. 4: Removing the pinion flange

  1. Matchmark and disconnect the front driveshaft at the carrier.
  2.  
  3. Remove the wheels.
  4.  
  5. Dismount the calipers and wire them up, out of the way.
  6.  
  7. Position an inch pound torque wrench on the pinion nut. Measure the torque needed to rotate the pinion one full revolution. Record the figure.
  8.  
  9. Matchmark the pinion flange, shaft and nut. Count and record the number of exposed threads on the pinion shaft.
  10.  
  11. Hold the flange and remove the nut and washer.
  12.  
  13. Using a puller, remove the flange.
  14.  
  15. Carefully pry the seal from its bore. Be careful to avoid scratching the seal bore.
  16.  
  17. Remove the deflector from the flange.
  18.  

To install:
  1. Clean the seal bore thoroughly.
  2.  
  3. Remove any burrs from the deflector staking on the flange.
  4.  
  5. Tap the deflector onto the flange and stake it in three places.
  6.  
  7. Position the new seal in the carrier bore and drive it into place until flush. Coat the seal lips with wheel bearing grease.
  8.  
  9. Coat the outer edge of the flange neck with wheel bearing grease and slide it onto the pinion shaft.
  10.  
  11. Place a new nut and washer onto the pinion shaft and tighten it to the position originally recorded. That is, the alignment marks are aligned, and the recorded number of threads are exposed on the pinion shaft.
  12.  


WARNING
Never hammer the flange onto the pinion!

  1. Measure the rotating torque of the pinion. Compare this to the original torque. Tighten the pinion nut, in small increments, until the rotating torque is 3 inch lbs. (0.35 Nm) GREATER than the original torque.
  2.  
  3. Install the driveshaft.
  4.  
  5. Install the calipers and install the wheels.
  6.  

 
label.common.footer.alt.autozoneLogo