Suspension arm ball joint worn
How it can appear on an MOT certificate
- “Suspension arm ball joint has slight play”
- “Suspension ball joint excessively worn”
- “Lower arm ball joint dust cover deteriorated”
What it is
Ball joints connect the suspension arms to the wheel hubs, letting the wheel move up and down and steer. They wear over time and are protected by a rubber dust cover.
Why it matters
A worn ball joint can cause knocking noises and vague steering. In extreme cases a joint can separate, which is very dangerous. A split dust cover lets in dirt and speeds up wear.
What to check when viewing a car
Listen for knocks over bumps and when turning at low speed. Ask whether the joint or arm was replaced if it was advised before.
Has the car you're looking at had this before?
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What the MOT categories mean
- Dangerous
- A direct and immediate risk to road safety, or a serious impact on the environment. The car fails and shouldn't be driven until it's repaired.
- Major
- It may affect the car's safety, put other road users at risk or harm the environment. The car fails and should be repaired straight away.
- Minor
- No significant effect on safety or the environment. The car passes, but it should be repaired as soon as possible.
- Advisory
- Something to keep an eye on that could need repairing in future. The car passes.
Related: suspension and steering
- Coil spring fractured or broken
- Shock absorber leaking or worn
- Suspension arm pin or bush worn
- Anti-roll bar linkage (drop link) worn
- Anti-roll bar bush or mounting worn
- Steering rack gaiter split or damaged
Buying a used car?
General information about this type of MOT defect, not advice about a particular car. How serious it is depends on the car; have any car you're buying inspected by a qualified mechanic.