MOT defect file
Ball joint worn
Last updated
Quick answer
Play has developed in a steering or suspension ball joint. Affects handling and tyre wear, and worsens over time.
- Typical cost
- £120–£280
- DIY viability
- Possible with care
What you might notice
- A knock or clunk from the front when turning at low speed or crossing uneven ground
- Steering that feels loose around the straight ahead, with a dead spot before the car responds
- A squeak or creak from one corner as the suspension moves, often the joint running dry after its gaiter split
- A torn, split or missing rubber gaiter visible behind the wheel — the warning that usually arrives first
What causes it
- A perished or split dust gaiter letting grit and water into the joint, which then wears rapidly
- Ordinary mileage — most joints last well beyond 100,000 miles provided the gaiter stays intact
- Impact damage from a pothole or kerb strike denting the socket
- Corrosion around the housing on older cars, most often at the track rod ends
Advisory or failure?
Slight play in a steering or suspension ball joint is a minor defect; excessive play is a major defect and a failure. Where a joint is worn or damaged badly enough that it is likely to separate — a fractured housing, a missing split pin or castellated nut, an insecure retaining device — the grading is dangerous and the car should not be driven away from the test. The gaiter is assessed in its own right: a deteriorating cover is a minor defect, and one damaged badly enough that it no longer keeps contamination out is a major, because the joint underneath is already on borrowed time even if it is still tight today.
Can you fix it yourself?
Possible with care
A track rod end is one of the more achievable jobs: separate the taper with a proper splitter rather than hammering it, count the threads or measure the position before you undo it, and have the tracking reset afterwards without exception. Lower ball joints are harder — many are pressed or riveted into the arm and are only sold as part of a complete arm, and cracking a seized taper takes real force in an awkward space. Everything you undo here goes back to a specified torque, with new split pins or nuts wherever the manufacturer calls for them.
What it costs
A track rod end is £15 to £35 in parts with under an hour of labour, which puts one side near the bottom of the band once alignment is added. A lower ball joint pressed into the arm costs more: £50 to £120 for a complete arm and one to two hours to fit. The top of the range is both sides together, or a car where the joint is integral to the hub carrier and the whole carrier has to be replaced. A four-wheel alignment at £40 to £70 afterwards is part of the job rather than an extra.
What happens if you ignore it
A ball joint that separates completely lets the wheel fold under the car, and there is no controlling that at any speed — it is one of the few failures where the outcome really is that stark. Long before that point the wear ruins tyres and holds the alignment out, so the joint quietly costs you money every month it is left. Because a badly worn joint is graded dangerous, continuing to use the car also means driving in a condition that carries a fine and penalty points.
This is general guidance, not a diagnosis. The severity DVSA records depends on the specific fault found, so the same item can appear as an advisory on one test and a failure on another. Ask a qualified tester or mechanic to inspect the vehicle.
Has this been recorded on your car?
Check the full MOT history for any UK registration.