Ball Joint Checking
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2001 Lincoln Navigator, 2001 Ford Pickup, 2001 Ford Expedition, 2000 Lincoln Navigator, and 2000 Ford Pickup. However, it is still accessible from the selected car via links, so may be relevant.
Turn off air suspension system, if equipped. Raise and support front of vehicle under lower control arm. Have assistant grasp tire at upper and lower edge. Move tire in and out in a rocking motion. Replace ball joint(s) if movement exceeds .03" (.79 mm).