How to check your car’s suspension

Safety: only do jobs you are confident with. Never work under a car supported only by a jack, and if a repair affects brakes, steering or suspension and you are unsure, have a garage do it or check your work.

Suspension is one of the biggest MOT failure areas. In 2025, 13.5% of car MOT tests failed on it, typically because of broken coil springs, worn ball joints and bushes, or leaking shock absorbers. UK potholes are hard on suspension, and many faults can be spotted at home.

Warning signs while driving

• Knocking or clunking over bumps, especially speed bumps: often worn drop links, bushes or a broken spring.
• A floaty or bouncy ride, or the car continuing to bob after a bump: worn shock absorbers.
• The car pulling to one side, or uneven tyre wear: worn components or alignment.
• A wandering feel on the motorway or vague steering.

Checks you can do at home

1. Does it sit level?

On level ground, stand back and look at the car from the front and rear. If one corner sits noticeably lower, a coil spring may be broken. Measure from the centre of each wheel to the arch above it: the two sides should be within about 1cm of each other.

2. Look at the springs

With a torch, look through the gap behind each wheel at the coil spring. A broken spring usually snaps near the bottom coil, and you may see a gap or a sharp, rusty broken end. Broken springs are one of the most common MOT failures on cars over about eight years old. Turning the steering to full lock helps you see the front ones.

3. The bounce test

Push down hard on each corner of the car and let go. It should come up once and settle. If it bounces two or three times, that shock absorber is worn.

4. Look for leaks

Shock absorbers are filled with oil. An oily, dirt-caked shock absorber body means its seal has failed. A leaking shock absorber that has lost its damping is an MOT failure.

5. Check the rubber boots

The ball joints and track-rod ends have small rubber gaiters. If these are split, dirt gets in and the joint wears quickly. A split gaiter on its own is usually an advisory, while a worn joint is a failure.

Common repairs

Drop links (anti-roll bar links)

Short rods connecting the anti-roll bar to the suspension, and the most common cause of a knocking noise over bumps. They are cheap and usually held by one nut at each end, so they are a reasonable DIY job: raise the car safely onto axle stands, remove the wheel, undo the two nuts (holding the ball-joint shaft still with an Allen key or Torx bit if it spins), and fit the new link. Seized nuts are common, so penetrating oil applied the day before helps. Tighten to the specified torque.

Coil springs

Replacing springs means compressing them, which stores a lot of energy. A spring compressor that slips can cause serious injury, so this is a job best left to a garage unless you have the right equipment and experience. Replace springs in pairs across an axle so the car sits level.

Shock absorbers

On many cars the front shock absorber is part of a strut with the spring around it, which also needs spring compression. Rear shocks on some cars are simpler, held by two bolts. Again, replace them in pairs.

Ball joints and bushes

These usually need a press or a special tool and are often replaced as part of a complete wishbone (control arm). Often a garage job, and the car will need a wheel alignment afterwards.

Safety when working on suspension

• Always support the car on axle stands on firm, level ground. Never rely on a jack alone.
• Chock the wheels that stay on the ground.
• Use new self-locking nuts where specified, and torque everything to the manufacturer’s figures.
• Get the wheel alignment checked after replacing steering or suspension parts.

Which cars fail on suspension most?

From our analysis of every car MOT in 2025, these popular models failed on suspension most often. If you own or are buying one, it is worth checking this area more carefully. Older cars naturally fail more, so the figures partly reflect each model’s age.

See every model in our MOT data by model.

A recurring suspension advisory in a car’s MOT history, such as “anti-roll bar linkage ball joint has slight play”, often becomes a failure at the next test.