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