Tools Required

J 8001  Dial Indicator

Fig 1: Identifying J 8001 Dial Indicator

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.

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.
3. Wipe the ball joint clean. Check the seals for cuts or tears.

   Important:  If a seal is cut or torn, replace the lower control arm.

4. Check the wheel bearings for looseness. If looseness in the wheel bearings is present, refer to Wheel Bearings Diagnosis  .
5. Check the ball joint for horizontal looseness.
   1. 5.1. Position the J 8001  against the lowest outboard point on the wheel rim.
   2. 5.2. Rock the wheel in and out while reading the J 8001  . This shows horizontal looseness in the lower ball joint.
   3. 5.3. The J 8001  reading should be no more than 3.18 mm (0.125 in). If the reading is too high, check the lower ball joint for vertical looseness.
   Fig 2: Ball Joint Inspection

   Courtesy of GENERAL MOTORS CORP.
6. Check the lower ball joint 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.
   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 control arm. Refer to LOWER CONTROL ARM in Front Suspension.
   3. 6.3. Pry between the lower control arm and the steering knuckle while reading the J 8001.  This shows vertical looseness in the ball joint. The lower ball joint is not preloaded and may show some looseness.
   4. 6.4. If the J 8001  reading is more than 3.18 mm (0.125 in), replace the lower control arm. Refer to LOWER CONTROL ARM in Front Suspension.