GM Astro/Safari 1985-1996 Repair Guide

Knuckle, Hub and Bearings

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REMOVAL & INSTALLATION



You will need an approved ball joint separator (NOT A PICKLE FORK), along with any tools which are required for halfshaft removal (as covered in Drive Train of this guide).

  1. Remove 2 / 3 of the fluid from the brake reservoir.
  2.  
  3. Raise the vehicle and support with jackstands.
  4.  
  5. Remove the front wheels. Place a protective cover over the halfshaft boots.
  6.  


CAUTION
Some brake pads 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.

  1. Remove the brake caliper as outlined in Brakes . Support the caliper (with the brake line still attached) aside with a piece of wire.
  2.  
  3. Remove the brake disc, halfshaft nut and washer.
  4.  
  5. Remove the retaining nut, then disconnect the tie rod end from the knuckle using a tie rod separator.
  6.  
  7. Remove the hub and bearing assembly. Most AWD vehicles use a sealed hub and bearing assembly that is bolted to the knuckle. Loose and remove the mounting bolts, then if necessary, use a puller to separate the assembly from the halfshaft.
  8.  
  9. Remove the halfshaft as outlined in Drive Train of this guide.
  10.  
  11. If necessary, remove the splash shield from the knuckle.
  12.  
  13. Support the lower control arm with jackstands.
  14.  
  15. Remove the upper ball joint nut and disconnect the joint from the knuckle using a ball joint separator.
  16.  
  17. Remove the lower ball joint nut and disconnect the joint from the knuckle using a ball joint separator.
  18.  
  19. Remove the knuckle from the vehicle. Check and, if necessary, remove the old seal from the knuckle.
  20.  

The front wheel bearings are a sealed unit that requires no periodic maintenance or repacking. The hub and bearing has to be replaced as a unit if defective.

To install:
  1. If removed, install a new seal into the knuckle using a seal installer J-36605.
  2.  
  3. Install the knuckle to the upper and lower ball joints. Install and tighten the nuts, but do not tighten fully at this time, they must be tightened with the suspension at normal compression and ride height.
  4.  
  5. If removed, install the splash shield.
  6.  
  7. Install the halfshaft assembly.
  8.  

Obviously, you cannot install the shaft washer and nut until after the hub and bearing assembly has been installed, but it will be easier to keep the shaft from turning if you wait until the brake caliper is installed as well.

  1. Install the hub and bearing assembly. Torque the bolts to 66 ft. lbs. (90 Nm).
  2.  
  3. Install the tie rod end to the steering knuckle. Tighten the nut and install a new cotter pin.
  4.  
  5. Install the brake disc and caliper
  6.  
  7. If not done earlier, install the halfshaft washer and nut, then tighten to specification. For details, please refer to Drive Train of this guide.
  8.  
  9. Install the front wheels.
  10.  
  11. Remove the jackstands and carefully lower the vehicle.
  12.  
  13. Properly refill the brake master cylinder. Pump the brake pedal a few times to seat the brake pads before moving the vehicle. DO NOT attempt to move the van until a firm pedal is obtained.
  14.  
  15. If not done earlier, tighten the upper and lower ball joint nuts to specification and install new cotter pins. For details, please refer to the ball joint procedures found earlier in this section.
  16.  
  17. Recheck all fasteners for proper torque and assembly.
  18.  
  19. Check and adjust the front end alignment, as necessary.
  20.  

 
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