Lower Ball Joint

Lower ball joint wear may be checked without disassembling ball stud. Raise and support vehicle at wheel and hub with jack stand.
Measure distance between top of ball joint stud and tip of lower grease fitting. See Fig 2. Move support to lower control arm and allow wheel and hub to hang free.
Recheck distance. If difference between measurements exceeds .094" (2.38 mm), replace ball joint. Inspect lower ball joint rubber grease seal for cuts or tears. Replace ball joint if damage is found.

Fig 1: Exploded View of Typical Front Suspension

Courtesy of GENERAL MOTORS CORP.

Fig 2: Checking Lower Ball Joint Wear

Courtesy of GENERAL MOTORS CORP.