Knocking Noise Over Bumps? Common Suspension Problems Explained

What that knocking usually is

A knock or clunk over speed bumps, potholes or rough roads is one of the most common noises we hear. It almost always comes from a suspension part that has worn and now has play in it.

The noise is often loudest at low speed, going over a bump on one side, or turning at the same time.

The usual suspects

Anti-roll bar drop links are the most frequent cause, and they are usually a straightforward repair. Worn bushes in the wishbones or subframe, worn ball joints, broken coil springs and tired shock absorber top mounts are also common.

Coil springs can snap, often near the bottom coil, and give a sharp clunk or a car that sits lower on one corner. Pothole-heavy roads around the Black Country do suspension no favours.

Why it matters

Worn suspension affects how the car steers, brakes and holds the road. It also wears tyres unevenly and can knock the wheel alignment out. Many worn suspension parts, including broken springs, excessive play in ball joints and worn bushes, are MOT fails.

Shock absorbers

Worn shock absorbers do not always knock. Instead the car may feel floaty, bounce after a bump, dip heavily under braking or feel unsettled on the motorway. A leaking shock absorber is an MOT fail.

How we find the noise

We road test the car to hear the noise for ourselves, then lift it and check every joint and bush for play. That way we replace the part that is actually worn rather than guessing. If alignment is affected afterwards, we can check and set it too.

If your car has started knocking, call us on 0121 544 3736 or bring it to us on Park Lane in Oldbury.