GM Service Manual Online
For 1990-2009 cars only
  1. Check the front lower control arm ball stud tightness in the knuckle boss whenever you inspect the front lower control arm ball stud.
  2. Raise the vehicle while allowing the front suspension to hang free.
  3. Grasp the tire at the top and the bottom.
  4. Move the bottom of the tire in an in-and-out motion while checking for movement of the stud end or castellated nut at the knuckle boss.
  5. A loose castellated nut may indicate a bent stud or a damaged hole in the knuckle boss.
  6. Observe any horizontal movement of the knuckle relative to the control arm.
  7. Replace the ball joints/studs if you detect any looseness in the joint or if the ball joint seal is cut.
  8. Replace worn or damaged parts with the correct service parts.
  9. Failure to use the correct front lower control arm ball stud and specified fastener torque may eventually cause a loose joint. This may result in loss of steering control which could result in personal injury.