Car clunking over bumps: front and rear noise diagnosis
Updated 23 July 2026 · OBDCode UK editorial
Can you keep driving?
Book an inspection soon. Stop driving if steering feels loose, the car changes direction over bumps, a spring is broken near the tyre, or braking causes a heavy knock. Never crawl under a car supported only by its jack.
Match what the car is doing
| What you notice | Most likely | How to separate it |
|---|---|---|
| Fast light rattle on rough roads | Drop link or anti-roll-bar bush | Often quieter on a full-width speed hump where both wheels move together. |
| Single clunk while braking/accelerating | Control-arm bush or ball joint movement | Loaded inspection and pry-bar check by a technician. |
| Clunk while steering as well | Top mount, spring seat or ball joint | Listen stationary while an assistant turns the wheel; inspect spring seating. |
| Rear knock only | Shock bush, rear link, exhaust or loose boot item | Remove cargo/spare-wheel tools and check exhaust clearances before suspension parts. |
Checks to do before buying parts
- Remove loose items from boot, spare-wheel well and door pockets.
- Compare one-wheel potholes with full-width speed humps and note front/rear/left/right.
- Read the latest MOT history for recurring suspension advisories.
- Have joints checked under load; an unloaded wheel can hide movement.
Typical UK costs
| Likely job | Typical fitted price |
|---|---|
| Drop links/bushes | £80–£220 |
| Coil spring pair | £180–£400 |
| Control arm/ball joint | £140–£550 |
| Top mounts/shock absorbers | £180–£550 per axle |
Indicative 2026 independent-garage prices for mainstream cars; London, prestige, SUV and seized-part jobs can cost more. Diagnose first.
MOT relevance
Excessive wear, insecurity, a fractured spring or a component likely to detach can fail. A noise alone is not the test criterion, but it is often the first warning of measurable play.
Frequently asked questions
Why does it clunk over small bumps but not speed humps?
Small alternating wheel movements load anti-roll-bar links differently; both wheels rising together can make a worn link quieter.
Can a drop link noise pass an MOT?
A link can make noise before play reaches the fail threshold. Passing does not prove the source is safe or correctly diagnosed.
Sources and further reading
General guidance for UK drivers, not professional advice. MOT rules follow the DVSA inspection manual (2026 edition).