Tools Required

J 8001  Dial Indicator

Fig 1: Inspecting Ball Joint

Courtesy of GENERAL MOTORS CORP.

Important: 

• The vehicle must rest on a level surface.
• The vehicle must be stable. Do not rock the vehicle on the jack stands.
• The upper control arm bumper must not contact the frame.

1. Raise and support the vehicle with safety stands.
2. Support the lower control arm with a jack stand, as far outboard as possible, near the lower ball joint.

   Important:  If a seal is cut or torn, replace the ball joint.

3. Wipe the ball joints clean. Check the seals for cuts or tears.
4. Check the wheel bearings for looseness. If looseness in the wheel bearings is present, refer to Wheel Bearings Diagnosis (Sealed)  .
5. Check the ball joints for horizontal looseness.
   1. 5.1. Position the J 8001  dial indicator against the lowest outboard point on the wheel rim.
   2. 5.2. Rock the wheel in and out while reading the dial indicator. This shows horizontal looseness in both joints.
   3. 5.3. The dial indicator reading should be no more than 3.18 mm (0.125 in). If the reading is too high, check the lower ball joints for vertical looseness.
6. Check the lower ball joints for wear and for vertical looseness using the following procedure:
   1. 6.1. Inspect by sight the lower ball joint for wear. The position of the housing into which the grease fitting is threaded indicates wear. This round housing projects 1.27 mm (0.050 in) beyond the surface of the lower ball joint cover on a new ball joint. Under normal wear, the surface of the lower ball joint housing retreats inward very slowly.
   Fig 2: Check Ball Joints For Vertical Looseness
   Courtesy of GENERAL MOTORS CORP.
   2. 6.2. First observe, then scrape a scale, a screwdriver, or a fingernail across the cover. If the round housing is flush with or inside of the cover surface, replace the lower ball joint. Refer to LOWER BALL JOINT REPLACEMENT (COIL SPRING SUSPENSION) or LOWER BALL JOINT REPLACEMENT (TORSION BAR SUSPENSION) .
7. Place a J 8001  dial indicator (1) against the spindle in order to show vertical movement.
   Fig 3: Checking Vertical Movement

   Courtesy of GENERAL MOTORS CORP.
8. Pry between the lower control arm (2) and the outer bearing race (1) while reading the dial indicator. This shows vertical looseness in the ball joints. The lower ball joint is not preloaded and may show some looseness.
Fig 4: Checking Vertical Looseness In Ball Joints
Courtesy of GENERAL MOTORS CORP.
9. If the dial indicator reading is more than 3.18 mm (0.125 in), replace the lower ball joint. Refer to LOWER BALL JOINT REPLACEMENT (COIL SPRING SUSPENSION) or LOWER BALL JOINT REPLACEMENT (TORSION BAR SUSPENSION) .
10. If the lower ball joint is within specifications, and there is too much horizontal looseness, check the upper control arm for wear.

    If you find any looseness or can twist the stud with your fingers, replace the upper control arm. Refer to UPPER CONTROL ARM REPLACEMENT .