What are Ball Joints?
Ball-and-socket pivots that let your wheels steer and move up and down at the same time.
Simplified animation — not to scale.
In plain English
A ball joint is a sealed ball-and-socket connection between the suspension arm and the wheel hub (or between steering links). It lets the wheel turn left and right while also bouncing up and down over bumps.
"Like the joint at the base of your thumb — fine when it's lubricated and sealed, painful and wobbly once something gets in."
How it works
A hardened steel ball sits in a greased cup, sealed by a rubber boot. As long as the grease stays in and dirt stays out, the joint moves smoothly. If the boot splits, water and grit get in, the ball wears, and the joint develops play that you can hear and feel.
Signs of trouble
- ⚠Knocking or clunking from the front when going over bumps
- ⚠Loose, sloppy or rattly steering, especially at low speed
- ⚠Uneven tyre wear on the inner or outer edge
- ⚠MOT failure for excessive play in a ball joint
- ⚠Split rubber boot visible at the joint
£100 – £300 per joint fitted
Always get a written quote. Prices vary by car, region, and parts brand.