Ball Joint Checking
- Turn air suspension off (if equipped). Air suspension can be turned off by turning off air suspension switch located in luggage compartment. Raise and support vehicle. Check ball joint boots for tears. Check wheel bearings. See FRONT WHEEL BEARINGS . Ensure there is zero wheel bearing side movement.
- Support front lower control arm. Support vehicle in normal driving position. Push and pull on top and bottom of tire. Observe any lateral backlash in ball joint between lower or upper control arm and spindle assembly. If backlash exists. Remove appropriate ball joint from spindle assembly and go to next step.
- Attach dial indicator to appropriate control arm with tip of dial indicator resting against side of ball joint shaft. Move ball joint shaft horizontally to check for lateral backlash. See Fig 1. Maximum allowable lateral backlash for lower ball joint is .04" (1.0 mm), and for upper ball joint is .015" (.40 mm).
- Reposition tip of dial indicator to top of ball joint shaft. Move ball joint vertically to check for end play. See Fig 2. Maximum allowable end play for both lower and upper ball joints is .02" (.5 mm). Replace ball joints as necessary.
Courtesy of FORD MOTOR CO.
Courtesy of FORD MOTOR CO.