Ball joints and bushings

The pivots and rubber mounts that let suspension parts move — and the wear items an inspector checks.

Also called: ball joint · control arm bushing

What it means

Definition

Ball joints are the pivots connecting the control arms to the steering knuckle, letting the wheel steer while the suspension travels. Bushings are the rubber or polyurethane sleeves that let arms pivot where they attach to the body. Both are wear items with defined inspection tests: Virginia's code states there should be no noticeable play detected in the ball joints when checked in the prescribed manner, and fails a bushing worn to the extent that the component can be moved by hand along the axis of the component.

Why a buyer cares

What it changes

These are the components behind most suspension clunks, and the state test for them is observational rather than a matter of judgement — which makes it something an inspecting mechanic can answer plainly.

In practice

Where you meet it

Under steering and suspension on an inspection sheet, checked with the vehicle raised.

Two things that look alike

Not the same as

A tie rod end connects the steering linkage to the knuckle; a ball joint connects the control arm to it.

Where this comes from

Sources

One state's criteria. Others word the test differently.