Anti-Roll Bar Link Excessive Play — MOT Failure Explained

The small link that connects the anti-roll bar to the suspension has developed play in one of its ball joints. It's the classic cause of a light rattle or knock over rough surfaces at low speed, and it's one of the cheapest suspension faults there is.

Wording as it commonly appears on an MOT certificate: “Anti-roll bar linkage ball joint has excessive play”.

What does it mean?

How serious is it?

Usually recorded as: Minor, Major. The tester assesses the actual vehicle on the day, so your certificate is what counts.

What normally causes it?

Split rubber boots on the link's ball joints, letting water and grit in
Age — links live right in the spray from the front wheels
Impact damage from a big pothole

What a mechanic would check

Grab each link and try to move it by hand — a good one is solid, a worn one rocks or clicks. I'd check both sides even if only one failed, because they wear at the same rate and it's daft labour to do them separately.

What might need replacing

Anti-roll bar drop links, replaced as a pair
Anti-roll bar bushes if they're also perished

Can you still drive it?

Whether this is recorded as Minor or Major depends on how much play there is. It's rarely the most urgent item on a certificate, but it's cheap enough that there's no sense leaving it — and worn links let the anti-roll bar bang about, which wears the bar bushes next.

Repair cost

This is one of the more affordable suspension repairs on most cars. The parts are small and the job is usually quick, unless the links have seized solid and have to be cut off.

Before the retest

Suspension parts such as springs, shock absorbers and drop links are normally replaced in pairs across an axle so the car sits level and handles evenly. Any work that disturbs the steering or suspension geometry is worth following with a wheel alignment check, otherwise you can pass the retest and still wear out a new pair of tyres within months. Listen for the original knock again on a bumpy road before the retest — if it is still there, something was missed.

Retest rules

If the vehicle stays at the test centre for repair and is retested within 10 working days, a partial retest is often free; some items qualify for a free retest if you bring the car back by the end of the next working day. The exact conditions are set out on GOV.UK, so confirm with the test centre before you leave. A major or dangerous failure means the car cannot legally be driven away unless the previous MOT is still valid and nothing dangerous was recorded — check your certificate first.

This is general guidance from a UK mechanic, not a substitute for a physical inspection. Only the tester who inspected your vehicle can confirm what was recorded and why.

Anti-roll bar linkage has excessive play — MOT failure explained