GM Astro/Safari 1985-1996 Repair Guide

Upper Ball Joint

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INSPECTION



See Figures 1 and 2



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Fig. Fig. 1: To check the ball joint, first wipe the grease and road crud off the it for a visual inspection



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Fig. Fig. 2: Checking for ball joint looseness

Before performing this inspection, make sure the wheel bearings are adjusted correctly and that the 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 3, 4, 5 and 6



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Fig. Fig. 3: Use a separator tool to free the upper ball joint from the steering knuckle



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Fig. Fig. 4: Drill pilot holes in the upper ball joint rivets ...



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Fig. Fig. 5: ... then drill off the rivet heads



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Fig. Fig. 6: When installing a service replacement upper ball joint, be sure the bolts are positioned on the bottom (nuts on top)

The following procedure requires the use of the GM Ball Joint Remover tool No. J-23742 or equivalent.

  1. Raise and support the front of the vehicle by placing jackstands under the lower control arms, between the spring seat and the lower ball joint. If jackstands are placed anywhere else, a floor jack MUST be used between the spring seat and the lower ball joint.
  2.  

Allow the jackstand or jack to remain under the lower control arm seat, to retain the spring and the lower control arm position.

  1. Remove the tire and wheel assembly.
  2.  
  3. From the upper ball joint, remove the cotter pin, the nut and the grease fitting.
  4.  
  5. Using the GM Ball Joint Remover tool No. J-23742 or equivalent, separate the upper ball joint from the steering knuckle. Pull the steering knuckle free of the ball joint after removal and wire it to the body.
  6.  

After separating the steering knuckle from the upper ball joint, be sure to support steering knuckle/hub assembly to prevent damaging the brake hose.

  1. Remove the upper ball joint from the upper control arm:
    1. Using a 1 / 8 in. (3mm) bit, drill a 1 / 4 in. (6mm) deep hole into each rivet.
    2.  
    3. Using a 1 / 2 in. (13mm) bit, drill off the rivet heads.
    4.  
    5. Using a pin punch and the hammer, drive the rivets from the upper ball joint-to-upper control arm assembly and remove the upper ball joint.
    6.  

  2.  

To install:
  1. Clean and inspect the steering knuckle hole. Replace the steering knuckle, if any out of roundness is noted.
  2.  
  3. Install a service replacement upper ball joint, positioning the ball joint-to-upper control arm bolts facing upward.
  4.  
  5. Tighten the upper ball joint-to-upper control arm bolts to the specification provided with the replacement joint. If no specification was provided, tighten the bolt to 96 inch lbs. (11 Nm) for 1985-89 vehicles or to 22 ft. lbs. (30 Nm) for 1990-96 vehicles.
  6.  
  7. Remove the steering knuckle support, then seat the upper ball joint into the steering knuckle and install the nut. Make sure the ball joint is FULLY SEATED into the steering knuckle, then tighten the upper ball joint-to-steering knuckle nut to 52 ft. lbs. (70 Nm) for 1985-87 vehicles, or to 65 ft. lbs. (85 Nm) on 1988-96 vehicles.
  8.  
  9. Install a new cotter pin to the lower ball joint stud.
  10.  

When installing the cotter pin through the upper ball joint-to-steering knuckle nut, if the hole is not clear, always tighten the castle nut additionally to expose the cotter pin hole. NEVER loosen the nut for alignment.

  1. Install the grease fitting, then lubricate the upper ball joint using a grease gun.
  2.  
  3. Install the tire and wheel assembly.
  4.  
  5. Inspect and/or adjust the wheel bearing and the front end alignment.
  6.  
  7. Remove the jackstands and carefully lower the vehicle.
  8.  

 
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