Why cars fail their MOT on wheels (and what it costs)
Loose wheel nuts, worn bearings and a distorted rim fail 0.95 percent of car MOTs. Cheap to fix, but one of the most dangerous defects to ignore.
MOT DATA · 4 min read
Three different faults, one small category
Wheel faults fail 0.95 percent of car MOTs, split across three genuinely different problems that just happen to share the word wheel: a loose or missing wheel nut, bolt or stud (0.33 percent), a worn wheel bearing (0.53 percent), and a wheel that is fractured, welded or badly distorted (0.10 percent). It is one of the smaller categories by volume, but the loose-fixing fault is graded dangerous, not just major, because a wheel that comes off at speed is about as bad as an MOT defect gets.
What fails
Loose or missing wheel nuts usually trace back to a recent wheel-off job, a garage or tyre fitter that under-torqued or over-torqued the fixings, or corrosion seizing a nut so it never sits flush again. A wheel bearing runs the hub the wheel bolts to; it wears with age and mileage like any bearing, and starts as a low rumble that gets louder and changes pitch on a bend before it fails outright. A fractured, welded or badly distorted wheel is usually kerb or pothole damage: a steel wheel bends, an alloy cracks, and either way DVSA does not allow a welded repair on a road wheel.
What it costs
Wheel nuts and studs are a few pounds each, and correcting a loose one is minutes of labour if a garage catches it before it costs you the wheel. A wheel bearing is a bigger job: parts and labour typically run seventy to two hundred pounds a corner, more on cars where the bearing comes as a sealed hub assembly rather than a bearing you can press in on its own. A fractured or badly distorted wheel cannot be legally welded back into service, so it means a replacement: a used alloy in the right fitment is often forty to a hundred pounds, new or from a main dealer considerably more.
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The salvage angle
A loose-fixing fail is the cheapest possible outcome on this whole site's list of failures and also the one most worth actually checking in person, since a lot photographed with the wheels on tells you nothing about torque. A wheel bearing rumble is easy to miss on a short test drive and easy to blame on tyre noise, so listen specifically on a bend, where a bad bearing gets noticeably louder. A distorted or fractured wheel from an impact is also worth reading against the rest of the lot's damage description: a bent wheel on a car with front or corner impact damage is a small tell that the same impact reached the suspension and steering behind it, not just the wheel itself.
Where to get the parts
Sourcing the part yourself rather than leaving it to a garage's mark-up is usually where the saving is. GSF Car Parts carries most of what a job like this needs, with click and collect from local branches.
Browse parts at GSF Car Parts →
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