Yes, a strut top mount can fail an MOT in the UK if it is worn, loose, cracked, excessively corroded or causes unsafe suspension movement, steering instability or knocking noises.
A strut top mount can fail an MOT if it has excessive play, loose fixings, badly worn rubber, a damaged or seized bearing, visible movement, corrosion around the mounting area, or any defect that affects suspension security.
Minor rubber wear may receive an advisory, but serious looseness, knocking, rough steering or insecure mounting should be repaired before the test.
The tester is checking whether the suspension strut is securely mounted and whether the top mount is allowing excessive movement. If the mount is loose, badly worn or the surrounding structure is weak, it can affect steering, braking stability and tyre contact.
These are the practical points that matter during a suspension inspection.
The top mount should hold the strut securely without loose fixings or excessive movement.
Visible movement, knocking or lift at the mount can point to worn rubber, loose fixings or a damaged bearing.
Rust, cracks or damage around the suspension turret or mounting area can become a serious MOT issue.
A rough, seized or noisy top mount bearing can affect steering movement on front strut setups.
Badly split or collapsed rubber can allow abnormal suspension movement.
Shock absorbers, springs, drop links and lower arms can cause similar symptoms.
These faults should be repaired before test day if they are obvious.
Too much movement in the top mount can affect suspension control and steering stability.
Loose nuts, bolts or mounting hardware can make the suspension strut insecure.
Badly deteriorated rubber can reduce support and allow abnormal movement.
A rough or seized top mount bearing can affect steering rotation on front strut setups.
Rust, cracks or impact damage around the mounting area can become an MOT issue.
Any defect that affects suspension security or vehicle control can fail.
These symptoms often show up during low-speed driving, parking or driving over rough roads.
Often heard from the front suspension area, especially over speed bumps or potholes.
A creak, groan or twang when turning can point to a worn or dry top mount bearing.
A worn mount can knock when manoeuvring, braking lightly or driving over uneven roads.
The steering may feel rough, notchy or reluctant to self-centre.
The strut top may move more than expected when steering or bouncing the car.
Suspension movement can affect alignment and tyre contact.
Tyre tread MOT guide →On many front suspension designs, the strut top mount includes a bearing that lets the strut rotate as you steer. If this bearing wears, dries out or seizes, it can cause creaking, spring twang, notchy steering or clunks.
A rough top bearing can also make the spring twist and release suddenly when the steering is turned.
The rubber section helps absorb shock and hold the strut in position. When it collapses, splits badly or separates, the strut can move more than it should.
That movement can create knocking and may affect suspension security.
These checks can help you spot an obvious top mount problem before the MOT.
Listen for clunks, knocks or creaks over speed bumps, potholes and uneven roads.
Turn the steering and listen for grinding, twanging, creaking or notchy movement.
The steering should feel smooth and return normally, not bind or jump.
Look under the bonnet for rust, loose fixings, cracked rubber or unusual movement.
Uneven tyre wear can suggest suspension movement or alignment issues.
If you hear knocking, a garage can check the strut, mount, bearing, spring and related suspension parts properly.
Yes, if there is clear knocking, excessive movement, rough steering or visible damage. Strut top mounts are suspension safety components, and faults can worsen over time.
Top mounts are often replaced when fitting new shock absorbers or struts because much of the same labour is involved.
Not always, but it is sensible to check both sides. If one mount is worn due to age and mileage, the other side may also be tired.
For balanced suspension behaviour, many garages recommend replacing related parts in axle pairs where appropriate.
The final cost depends on the vehicle design, labour time and whether the strut or bearing is replaced at the same time.
Often moderate cost, depending on access and suspension design.
Commonly replaced together if the bearing is noisy, rough or seized.
Can cost more, but may be sensible if the shock absorber is also worn or leaking.
Alignment may be recommended after suspension work, especially if tyres are wearing unevenly.
Wheel alignment guide →Sometimes springs are inspected or replaced while the strut assembly is apart.
Coil spring guide →If the shock is leaking or weak, it may be sensible to replace it at the same time.
Shock absorber guide →A proper inspection is important before replacing parts.
Anti-roll bar links commonly knock over bumps and can sound like top mount noise.
Anti-roll bar link guide →Ball joint play can cause knocking, steering looseness and MOT failure risk.
Ball joint guide →Worn lower arm bushes can cause clunks, pulling and uneven tyre wear.
Lower arm guide →Track rod end wear can cause steering play and knocking.
Track rod guide →A broken spring can cause twanging, uneven ride height or knocking.
Coil spring guide →Leaking or weak shock absorbers can cause poor control, knocking and uneven tyre wear.
Shock absorber guide →These are common situations seen during MOT preparation and suspension diagnosis.
A seized top bearing can make the spring wind up and release suddenly when steering.
Drop links are common, but top mounts can create a similar knock over bumps.
The mount may be worn, but the surrounding metal also needs checking for corrosion.
Uneven ride height can point to springs, mounts, struts or suspension damage.
A rough top bearing can make steering feel sticky or slow to return.
Suspension movement and poor alignment can quickly damage tyres.
Common questions about noisy top mounts, worn rubber, bearings and MOT failure.
Yes, if the noise is linked to excessive wear, looseness or unsafe suspension movement.
Yes, they can be checked as part of suspension condition and security.
Yes, especially on front strut suspension where the mount includes a bearing.
Minor deterioration may be an advisory, but serious movement or damage can fail.
Not always, but many garages recommend checking both sides for even wear and balanced suspension behaviour.
Yes, if the mount allows movement that affects suspension geometry or alignment.
Yes, if it affects steering movement, causes unsafe operation or creates excessive strain in the suspension.
Have knocking, creaking, visible movement or rough steering inspected before the test.
Motor Vehicle Expert publishes practical UK-focused vehicle diagnostics, maintenance, MOT, warning light, used car and repair cost guidance based on common driver questions and real-world garage situations.
