Chevrolet Full Size Cars 1979-1989

Axle Shaft and Bearings

Print



Click image to see an enlarged view

Fig. Fig. 1 Cross section of a common axle shaft and bearing assembly



Click image to see an enlarged view

Fig. Fig. 2 Exploded view of a standard rear axle assembly



Click image to see an enlarged view

Fig. Fig. 3 Exploded view of a conventional differential case assembly



Click image to see an enlarged view

Fig. Fig. 4 Exploded view of a disc-type limited slip rear axle

Two types of axles are used on these models, the C and the non-C type. Axle shafts in the C-type are retained by C-shaped locks, which fit grooves at the inner end of the shaft. Axle shafts in the non C-type are retained by the brake backing plate, which is bolted to the axle housing. Bearings in the C-type axle consist of an outer race, bearing rollers, and a roller cage retained by snaprings. The non C-type axle uses a unit roller bearing (inner race, rollers, and outer race), which is pressed onto the shaft up to a shoulder. When servicing C or non C-type axles, it is imperative to determine the axle type before attempting any service. Before attempting any service to the drive axle or axle shaft, remove the axle carrier cover and visually determine if the axle shaft are retained by C-shaped locks at the inner end, or by the brake backing plate at the outer end.

REMOVAL & INSTALLATION




CAUTION
Brake shoes contain asbestos, which has been determined to be a cancer causing agent. Never clean the brake surfaces with compressed air! Avoid inhaling any dust from any brake surface! When cleaning brake surfaces, use a commercially available brake cleaning fluid.

Non C-Type


Click image to see an enlarged view

Fig. Fig. 5 Removing the axle shaft



Click image to see an enlarged view

Fig. Fig. 6 Nick the bearing retainer using a chisel non C-type axle

The non C-type may be found on a few of the earliest vehicles covered by this guide which are equipped with original rear axle assemblies. The design allows for a maximum axle shaft end-play of 0.022 in. (0.559mm), which can be measured with a dial indicator. If end-play is found to be excessive, the bearing should be replaced. Shimming the bearing is not recommended as this ignores end-play of the bearing itself and could result in improper bearing seating.

  1. Raise and support the rear of the vehicle safely using jackstands.
  2.  
  3. Remove the wheel and brake drum.
  4.  
  5. Remove the nuts holding the retainer plate to the backing plate. Disconnect the brake line, then plug the openings to prevent system contamination or excessive fluid loss.
  6.  
  7. Remove the retainer and install nuts, finger-tight, to prevent the brake backing plate from being dislodged.
  8.  
  9. Pull out the axle shaft and bearing assembly, using a slide hammer.
  10.  
  11. Using a chisel, nick the bearing retainer in three or four places. The retainer does not have to be cut, merely collapsed sufficiently, to allow the bearing retainer to be slid from the shaft.
  12.  
  13. Press off and discard the old bearing.
  14.  

To install:

  1. Install the new bearing by pressing it into position.
  2.  

Do not attempt to press the bearing and the retainer on at the same time.

  1. Press on the new retainer.
  2.  
  3. Assemble the shaft and bearing in the housing making sure that the bearing is seated properly in the housing.
  4.  
  5. Install the retainer to the backing plate and tighten the nuts.
  6.  
  7. Remove the plugs, then reconnect the brake line.
  8.  
  9. Install the drum, wheel and tire, then properly bleed the hydraulic brake system.
  10.  
  11. Remove the jackstands and carefully lower the vehicle.
  12.  

C-type


Click image to see an enlarged view

Fig. Fig. 7 Rear axle shaft C-lock and pinion shaft lockscrew locations



Click image to see an enlarged view

Fig. Fig. 8 Using a seal installation tool to drive the new seal into position



Click image to see an enlarged view

Fig. Fig. 9 Remove the cover from the rear axle housing allowing the fluid to drain into a large pan



Click image to see an enlarged view

Fig. Fig. 10 A spray cleaner will help eliminate some of the mess



Click image to see an enlarged view

Fig. Fig. 11 Loosen the pinion shaft lock-screw using a wrench



Click image to see an enlarged view

Fig. Fig. 12 Remove the lock-screw so the pinion shaft may be withdrawn



Click image to see an enlarged view

Fig. Fig. 13 Pull the pinion shaft from the differential in order to access the axle shaft C-lock



Click image to see an enlarged view

Fig. Fig. 14 If the axle shaft is pushed inward, the C-clock can be may be removed from the shaft groove



Click image to see an enlarged view

Fig. Fig. 15 Remove the brake drum so the axle shaft may be withdrawn from the housing



Click image to see an enlarged view

Fig. Fig. 16 Pull straight back to withdraw the shaft



Click image to see an enlarged view

Fig. Fig. 17 A prybar (or the end of the shaft) may be used to dislodge and remove the old bearing seal



Click image to see an enlarged view

Fig. Fig. 18 Use a suitably sized driver, socket or the smooth end of a length of pipe to drive the new seal into position

Most vehicles covered by this guide utilize rear axle shafts which are retained by C-locks positioned in the shaft grooves to hold the shafts in the differential case.

  1. Raise and support the rear of the vehicle safely using jackstands.
  2.  
  3. Remove the wheel and brake drum.
  4.  

When removing the cover from the rear axle housing, a small prytool may be used at the base of the cover to gently pry it back from the axle housing, breaking the gasket seal and allowing the lubricant to drain out into the container. Be careful not to use excessive force and damage the cover or housing.

  1. Place a large container underneath the rear axle, then clean the area surrounding the rear cover to help prevent dirt from entering the rear axle housing. Unscrew the retaining bolts, drain the gear oil and remove the rear cover.
  2.  
  3. Remove the differential pinion shaft lock-screw and the differential pinion shaft.
  4.  
  5. Push the flanged end of the axle shaft toward the center of the vehicle and remove the C-lock from the retaining groove at the end of the shaft.
  6.  
  7. Remove the axle shaft from the housing, being careful not to damage the oil seal, if it is not being removed.
  8.  
  9. Remove the oil seal by inserting the bottom end of the axle shaft behind the steel case of the oil seal. Pry the seal loose from the bore.
  10.  
  11. Seat the legs of the bearing puller behind the bearing. Seat a washer against the bearing and hold it in place with a nut. Use a slide hammer to pull the bearing.
  12.  

To install:

  1. Pack the cavity between the seal lips with wheel bearing lubricant and lubricate a new wheel bearing with same.
  2.  
  3. Use a suitable driver and install the bearing until it bottoms against the tube. Install the oil seal.
  4.  
  5. Slide the axle shaft into place. Be sure that the splines on the shaft do not damage the oil seal. Once the shaft is fully inserted, make sure that the splines engage the differential side gear.
  6.  
  7. Install the axle shaft C-lock on the inner end of the shaft and push the shaft outward so that the C-lock seats in the differential side gear counterbore.
  8.  
  9. Position the differential pinion shaft through the case and pinions, aligning the hole in the case with the hole for the lockscrew. Then install and tighten the lockscrew.
  10.  
  11. Use a new gasket and install the carrier cover. Be sure that the gasket surfaces are clean before installing the gasket and cover.
  12.  
  13. Fill the axle with lubricant to the bottom of the filler hole.
  14.  
  15. Install the brake drum and wheels.
  16.  
  17. Remove the jackstands and carefully lower the vehicle.
  18.  
  19. Check for leaks and road test the car.
  20.  

 
label.common.footer.alt.autozoneLogo