GM Astro/Safari 1985-1996 Repair Guide

Upper Ball Joint

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INSPECTION



See Figure 1



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Fig. Fig. 1: Checking for ball joint looseness

Before performing this inspection, make sure the wheel bearings and control arm bushings are in good condition.

  1. Raise and support the front of the vehicle by placing jackstands under each lower control arm as close as possible to each lower ball joint.
  2.  

Before performing the upper ball joint inspection, be sure the vehicle is stable and the lower control arm bumpers are not contacting the frame.

  1. Wipe the ball joints clean and check the seals for cuts or tears. If a seal is damaged the ball joint MUST be replaced.
  2.  
  3. Position a dial indicator so it contacts the wheel rim.
  4.  
  5. To measure the horizontal deflection, perform the following procedures:
    1. Grasp the tire (top and bottom), then pull outward on the top and push inward on the bottom; record the reading on the dial indicator.
    2.  
    3. Grasp the tire (top and bottom), then pull outward on the bottom and push inward on the top; record the reading on the dial indicator.
    4.  
    5. If the difference in the dial indicator reading is more than 0.125 in. (3.18mm), or if the ball joint can be twisted in its socket (with finger pressure) once it is disconnected from the knuckle, it must be replaced.
    6.  

  6.  

REMOVAL & INSTALLATION



See Figures 2 and 3



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Fig. Fig. 2: Exploded view of the service replacement upper ball joint



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Fig. Fig. 3: Upper ball joint separator tool

  1. Raise the front of the vehicle and support safely using jackstands.
  2.  
  3. Remove the front tire and wheel assembly.
  4.  
  5. Remove the brake hose and bracket from the upper control arm.
  6.  
  7. Loosen the riveted ball joint from the control arm:
    1. Drill a 1 / 8 in. (3mm) hole, about 1 / 4 in. (6mm) deep into each rivet.
    2.  
    3. Then use a 1 / 2 in. (13mm) drill bit, to drill off the rivet heads.
    4.  
    5. Using a pin punch and the hammer, drive out the rivets in order to free the ball joint from the control arm assembly.
    6.  

  8.  
  9. Remove the cotter pin and nut.
  10.  
  11. Remove the ball joint from the knuckle using a ball joint separator tool such as J-36607.
  12.  

To install:
  1. Position the new ball joint to the control arm.
  2.  
  3. Install the nuts and bolts supplied with the new ball joint. The bolt should be inserted from the top with the nut on the bottom. Tighten the nuts to 22 ft. lbs. (30 Nm).
  4.  
  5. Install the ball joint to the steering knuckle then secure using the nut. Tighten the nut to 95 ft. lbs. (128 Nm) for 1990-95 vehicles or to 66 ft. lbs. (90 Nm) for 1996 vehicles.
  6.  

The upper ball joint retaining nut MUST be tightened with the vehicle suspension at normal ride height. This can either be accomplished by installing the wheels and lowering the vehicle, or by moving jackstands under the ends of the lower control arms and resting the vehicle on them. If the latter solution is tried, make sure the the FULL WEIGHT of the vehicle front end is on the suspension.

  1. Install a new cotter pin to the castellated nut. Tighten the nut (but no more than an additional 1 / 6 turn) in order to align the cotter pin. DO NOT loosen the nut from the specified torque.
  2.  
  3. Connect the brake hose and bracket to the control arm.
  4.  
  5. If not done already, install the tire and wheel assembly, then remove the jackstands and carefully lower the vehicle.
  6.  
  7. Check and adjust the front end alignment, as necessary.
  8.  

 
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