# Clunking noise over bumps: what to check

Updated: 2026-10-24 · https://pros411.com/en/guides/mechanics/clunking-over-bumps

## Short answer

A clunk over bumps usually comes from a worn suspension part: a sway bar link, a shock or strut mount, a ball joint or a bushing. First empty the trunk of anything loose. Then do the bounce test and look for an oily, wet shock. Have it checked soon. If the steering feels loose or a wheel wobbles, do not drive: call a tow.

> Safety first: Do the checks parked on level ground with the parking brake set, never under a car held up only by a jack. A worn ball joint can let a wheel fold under the car: if the steering feels loose, the car wanders or a wheel looks tilted, do not drive it.

## What to check when your car clunks over bumps

![Cartoon car going over a speed bump with a loud clunk](https://pros411.com/img/guias/clunking-over-bumps.webp)

1. **Clunk! Every time you hit a bump.** A knock from under the car over speed bumps, potholes or driveways. Notice if it comes from the front or the back, and if it also happens in turns.
2. **The bounce test: push down hard.** Parked, push down hard on each corner and let go. A good shock settles after one bounce. If that corner keeps bouncing, the shock is worn.
3. **An oily, wet shock? It is worn.** Look behind each wheel with a flashlight. A shock covered in oily grime is leaking and no longer controls the bounce.
4. **Loose steering or a wobbly wheel? Stop.** If the steering feels loose, the car wanders or a wheel looks tilted, do not drive it. Call a tow or a mobile mechanic.
5. **Fixed: smooth over bumps again.** A mechanic lifts the car, finds the loose or worn part and replaces it. Links and bushings are often a quick fix.

## Common causes

- Sway bar links: a light clunk over small bumps, often on one side.
- Shocks, struts or their mounts: knocking over bumps, a bouncy ride and a nose dive when braking.
- Ball joints: a clunk over bumps and when turning. Serious: get it checked right away.
- Control arm bushings: clunks when braking, speeding up or over bumps.
- Not the suspension: a loose spare tire, a jack or a heat shield on the exhaust.

## What to tell the mechanic

Say when it happens: small bumps or big ones, turning, braking or all the time. Say which corner it seems to come from and when it started, for example after a pothole. If you can, record the sound on your phone.

## When to call a mechanic

- The steering feels loose or the car wanders (do not drive).
- A corner keeps bouncing in the bounce test, or a shock is wet with oil.
- The clunk gets louder or also happens when you turn or brake.
- The tires are wearing unevenly.

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## Frequently asked questions

### What causes a clunking noise over bumps?

Most often a worn sway bar link, shock or strut mount, ball joint or bushing. Sometimes it is just something loose in the trunk or a loose heat shield.

### Is it safe to drive with a clunking noise?

For a short trip to a shop, usually yes, if the steering feels normal. If the steering is loose, the car wanders or a wheel looks tilted, do not drive.

### How do I know if my shocks are bad?

The car keeps bouncing after bumps, dives forward when you brake or leans a lot in turns. A shock covered in oily grime is leaking. Try the bounce test on each corner.

### Can a bad ball joint cause a clunk?

Yes, often over bumps and when turning. A worn ball joint can fail and let the wheel fold under, so have it checked right away.

### Why does my car clunk over bumps at low speed?

Low-speed bumps like driveways and speed bumps load the suspension slowly, which makes loose links and worn bushings knock. A mechanic can find the play with the car on a lift.