Component Tests and General Diagnostics

Suspension System

Component Tests

Ball Joint Inspection

1. Prior to inspecting the ball joints for wear, inspect the wheel bearings. Install a new wheel bearing as necessary.

2. NOTE: In order to obtain accurate measurements, the suspension must be in full rebound with the weight of the vehicle supported by the frame.
Raise and support the vehicle by the frame to allow the wheels to hang in the rebound position.


3. Inspect the ball joint and ball joint boot for damage.
- If the ball joint or ball joint boot is damaged, install a new ball joint as necessary.


4. NOTICE: Do not use any tools or equipment to move the wheel and tire assembly or suspension components while checking for relative movement. Suspension damage may occur. The use of tools or equipment will also create relative movement that may not exist when using hand force. Relative movement must be measured using hand force only.

Inspect the ball joint for relative movement by alternately pulling downward and pushing upward on the lower control arm by hand. Note any relative vertical movement between the wheel knuckle and lower arm at the lower ball joint.
- If relative movement is not felt or seen, the ball joint is OK. Do not install a new ball joint.

- If relative movement is found, continue with Step 5.


5. NOTE: In order to obtain an accurate measurement, the dial indicator should be aligned as close as possible with the vertical axis (center line) of the ball joint.
To measure ball joint deflection, attach a suitable dial indicator with a flexible arm between the lower control arm and the wheel knuckle or ball joint stud.






6. Measure the ball joint deflection while an assistant pushes up and pulls down on the lower control arm, by hand.
- If the deflection exceeds the specification, a new ball joint must be installed.

- If the deflection meets the specification, no further action is required.