GM Astro/Safari 1985-1996 Repair Guide

Knuckle, Hub and Bearings



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.
  3. Raise the vehicle and support with jackstands.
  5. Remove the front wheels. Place a protective cover over the halfshaft boots.

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.
  3. Remove the brake disc, halfshaft nut and washer.
  5. Remove the retaining nut, then disconnect the tie rod end from the knuckle using a tie rod separator.
  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.
  9. Remove the halfshaft as outlined in Drive Train of this guide.
  11. If necessary, remove the splash shield from the knuckle.
  13. Support the lower control arm with jackstands.
  15. Remove the upper ball joint nut and disconnect the joint from the knuckle using a ball joint separator.
  17. Remove the lower ball joint nut and disconnect the joint from the knuckle using a ball joint separator.
  19. Remove the knuckle from the vehicle. Check and, if necessary, remove the old seal from the knuckle.

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.
  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.
  5. If removed, install the splash shield.
  7. Install the halfshaft assembly.

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).
  3. Install the tie rod end to