GM Astro/Safari 1985-1996 Repair Guide

Wheel Bearings

Print

Once every 30,000 miles (48,000 km) the non-sealed front wheel bearings of rear wheel drive vehicles should be cleaned and repacked with a GM Wheel Bearing Grease No. 1051344 or equivalent. Use only enough grease to completely coat the rollers. Remove any excess grease from the exposed surface of the hub and seal.

REPACKING & ADJUSTMENT



2-Wheel Drive

See Figures 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 and 20



Click image to see an enlarged view

Fig. Fig. 1: Exploded view of the front wheel hub and bearing assembly-2-wheel drive without ABS shown (ABS similar but with a speed sensor assembly on the shield and a reluctor ring on the back of the hub)



Click image to see an enlarged view

Fig. Fig. 2: Remove the dust cap from the center of the hub and disc assembly



Click image to see an enlarged view

Fig. Fig. 3: If the cap is stuck use a thin chisel to drive it away from the disc ...



Click image to see an enlarged view

Fig. Fig. 4: ... then pry the cap free, but be careful not to deform and ruin the cap



Click image to see an enlarged view

Fig. Fig. 5: Once loosened, remove the cap for access to the bearing retainer (cotter pin, washer and nut)



Click image to see an enlarged view

Fig. Fig. 6: Bend the ends outward and pull or lever the cotter pin from the spindle ...



Click image to see an enlarged view

Fig. Fig. 7: If difficulty is encountered, gently tap on the pliers with a hammer to help free the cotter pin



Click image to see an enlarged view

Fig. Fig. 8: ... then loosen and remove the castellated spindle nut



Click image to see an enlarged view

Fig. Fig. 9: Withdraw the thrust washer ...



Click image to see an enlarged view

Fig. Fig. 10: ... then remove the outer bearing, freeing the hub and disc assembly



Click image to see an enlarged view

Fig. Fig. 11: Pull the hub/disc assembly from the spindle and face downward on a clean working surface



Click image to see an enlarged view

Fig. Fig. 12: Remove the inner wheel bearing seal using a seal puller (this really makes the job easier) ...



Click image to see an enlarged view

Fig. Fig. 13: On ABS equipped vehicles a puller removes the seal WITHOUT damaging the reluctor ring (the visible teeth)



Click image to see an enlarged view

Fig. Fig. 14: With the seal removed, the inner wheel bearing may be lifted from the back of the hub



Click image to see an enlarged view

Fig. Fig. 15: Removing the bearings races from the hub and disc assembly



Click image to see an enlarged view

Fig. Fig. 16: Installing the inner wheel bearing race to the hub and disc



Click image to see an enlarged view

Fig. Fig. 17: Installing the outer wheel bearing race to the hub and disc



Click image to see an enlarged view

Fig. Fig. 18: Thoroughly pack the bearing with fresh, high temperature wheel-bearing grease before installation



Click image to see an enlarged view

Fig. Fig. 19: Apply a thin coat of fresh grease to the new inner bearing seal lip



Click image to see an enlarged view

Fig. Fig. 20: Though a driver is preferred, any circular tool (pipe or socket) of similar size can install the seal

Before handling the bearings, there are a few things that you should remember to do and not to do.

Remember to DO the following:


Remove all outside dirt from the housing before exposing the bearing.
 
Treat a used bearing as gently as you would a new one.
 
Work with clean tools in clean surroundings.
 
Use clean, dry canvas or plastic gloves.
 
Clean solvents and flushing fluids are a must.
 
Use clean paper when laying out the bearings to dry.
 
Protect disassembled bearings from rust and dirt. Cover them up.
 
Use clean rags to wipe bearings.
 
Keep the bearings in oil-proof paper when they are to be stored or are not in use.
 
Clean the inside of the housing before replacing the bearing.
 

Do NOT do the following:


Don't work in dirty surroundings.
 
Don't use dirty, chipped or damaged tools.
 
Try not to work on wooden work benches or use wooden mallets.
 
Don't handle bearings with dirty or moist hands.
 
Do not use gasoline for cleaning; use a safe solvent.
 
Do not spin-dry bearings with compressed air. They will be damaged.
 
Do not spin dirty bearings.
 
Avoid using cotton waste or dirty cloths to wipe bearings.
 
Try not to scratch or nick bearing surfaces.
 
Do not allow the bearing to come in contact with dirt or rust at any time.
 

The following procedures are made easier with the use of GM tools No. J-29117, J-8092, J-8850, J-8457 and J-9746-02 or their equivalents. Although the job can be done using a prybar, some a few LARGE sockets and some assorted drivers.

  1. Loosen the lug nuts on the front wheels.
  2.  
  3. Raise and support the front of the vehicle safely using jackstands.
  4.  
  5. Remove the front tire and wheel assemblies.
  6.  
  7. Remove the caliper-to-steering knuckle bolts and the caliper from the steering knuckle. Using a wire, support the caliper from the vehicle; DO NOT disconnect the brake line.
  8.  
  9. Remove the dust cap at the center of the hub and disc assembly.
  10.  
  11. Remove the cotter pin, the spindle nut, the thrust washer and the outer bearing.
  12.  
  13. Grasping the hub and disc assembly firmly, pull the assembly from the axle spindle.
  14.  
  15. Using a small prybar or an inexpensive seal removal tool, pry the grease seal from the rear of the hub/disc assembly, then remove the inner bearing.
  16.  

DO NOT remove the bearing races from the hub, unless they show signs of damage.

  1. If it is necessary to remove the wheel bearing races, use the GM front bearing race removal tool No. J-29117 to drive the races from the hub and disc assembly. If the tool is not available, you can use a prybar (if you take care not to damage the hub and disc assembly) or you can use a blunt drift from behind (the other side of the assembly).
  2.  

Wheel bearings and races which have been in service MUST remain together as matched sets. DO NOT switch bearings from side-to-side. ALSO, if the bearings are replaced, new races MUST be installed to insure the proper bearing operating life of the replacement parts.

  1. Using solvent, clean the grease from all of the parts, then blow them dry with compressed air.
  2.  

DO NOT spin the dry bearings with the compressed air or damage will likely occur. If compressed air is not available, place the bearings on a clean, dry surface (clean, lint free rag or a plastic bag) and allow them to air dry.

  1. Inspect all of the parts for scoring, pitting or cracking, replace the parts (if necessary).
  2.  

To install:
  1. If the bearing races were removed, perform the following procedures to the install the replacements:
    1. Using grease, lightly lubricate the inside of the hub/disc assembly.
    2.  
    3. Using the GM seal installation tools No. J-8092 and J-8850, drive the inner bearing race into the hub/disc assembly until it seats.
    4.  

  2.  

When installing the bearing races, be sure to support the hub/disc assembly with GM tool No. J-9746-02.

  1. Using the GM seal installation tools No. J-8092 and J-8457, drive the outer race into the hub/disc assembly until it seats.
  2.  

  1. Using wheel bearing grease, lubricate the bearings, the races and the spindle; be sure to place a gob of grease (inside the hub/disc assembly) between the races to provide an ample supply of lubricant.
  2.  

To lubricate each bearing, place a gob of grease in the palm of the hand, then scoop the bearing through the grease to force grease between the rollers and cage. Be sure to thoroughly fill the bearing around the entire circumference from the top and bottom of the assembly, then roll the bearing through the grease to assure it is well lubricated.

  1. Place the inner wheel bearing into the hub/disc assembly. Using a smooth flat driver, length of pipe or a large socket, drive the new grease seal into the rear of the hub and disc assembly until it is flush with the outer surface.
  2.  
  3. Position the hub and disc assembly onto the spindle, then install the outer bearing, thrust washer and the hub nut.
  4.  
  5. While turning the wheel, torque the hub nut to 12 ft. lbs. (16 Nm) until the bearings seat. Back off the nut to the "just loose'' position, then retighten it by hand. Back the nut off until the nearest nut slot aligns with the spindle hole. The nut should not be turned back more than 1 / 2 of a nut flat.
  6.  
  7. Install a new cotter pin through the nut and the spindle, then bend the ends and cut off the excess pin (one outward over the end of the spindle, and the other downward around the spindle). Install the grease cap.
  8.  
  9. If possible, use a dial indicator to the check the rotor end-play. The end-play should be 0.001-0.005 in. (0.03-0.13mm) when the bearings are properly adjusted. If not, readjust the hub/disc assembly.
  10.  
  11. Install the caliper onto the steering knuckle.
  12.  
  13. Install the tire and wheel assembly.
  14.  
  15. Remove the jackstands, then carefully lower the vehicle.
  16.  
  17. Tighten the lug nuts, then road test the vehicle.
  18.  

All Wheel Drive

The all wheel drive front wheel bearings are the sealed type that require no periodic adjusting or repacking. The bearing and hub is a 1 piece assembly requiring replacement if the bearings are defective. Refer to the "Front Wheel Bearing'' section in Suspension & Steering for bearing procedures.

 
label.common.footer.alt.autozoneLogo