Why does my car clunk when I go over bumps?
The short answer
A clunk over bumps usually means a worn suspension component — most often sway-bar links or control-arm bushings, sometimes ball joints or strut mounts. Small clunks are cheap fixes; a worn ball joint left too long can separate and drop the wheel’s support entirely. Worth a lift inspection soon.
Reviewed by Joe Zeiter
Service Director · Grote service team · Updated July 17, 2026
Likely causes, ranked
Worn sway-bar links
The most common clunk in salt country — small links with ball ends that rattle over washboard and speed bumps. Inexpensive to replace and instantly satisfying to have gone.
Control-arm bushings
Rubber bushings crack and hollow out with age, letting the arm knock against its mount over bumps and under braking. Often accompanied by vague steering and uneven tire wear.
Ball joints or strut mounts
Deeper, heavier clunks. These carry real load — a separated ball joint can let the wheel fold under the car. This is why clunks deserve diagnosis rather than a louder radio.
Loose exhaust hanger or heat shield
Not suspension at all — a rusted hanger lets the exhaust knock against the underbody over bumps. Easy to spot on a lift, cheap to fix.
What to do right now
- 1
Note when it clunks: small ripples (sway-bar links), big hits (control arms, mounts), or braking/turning (ball joints, tie rods).
- 2
Schedule a lift inspection — isolating a clunk from underneath takes minutes and beats guessing from the driver’s seat.
- 3
Don’t wait months. Bushings and links are cheap; the parts they protect are not.
What it typically costs
Sway-bar links from about $180. Control arms and ball joints are quoted per corner after inspection — typically $250–$600 per corner. At Grote Auto Service, suspension repairs include a post-repair alignment check, because new parts change the geometry.
Our diagnosis fee goes toward the repair.
Related questions
Can I keep driving with a clunk in the suspension?
A mild link rattle won’t strand you, but you can’t tell a harmless clunk from a failing ball joint by ear from the driver’s seat — and a separated ball joint is a lose-the-wheel event. Get it identified, then decide with real information.
Why did the clunk start after winter?
Freeze-thaw potholes hammer suspension components exactly when salt has been softening their rubber and rusting their joints all season. Spring is clunk season in northern Illinois — our lifts are full of them every March.
What actually fixes it
If it turns out to need real work, this is what usually does it — with pricing published up front, so there are no surprises.
Prefer we reach out?
We respond within the hour during business hours — usually faster.
This guide describes common patterns, not a diagnosis of your specific vehicle — that takes an inspection. If your symptom is marked urgent, treat it as urgent. When in doubt, stop driving and call (779) 888-5000.
Stop wondering. Start knowing.
A proper diagnosis costs less than a wrong guess — and ours is applied to the repair.
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