Ball joint worn

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.

Common questions

Does a split ball joint gaiter fail an MOT?

It can. A gaiter that is deteriorating but still doing its job is a minor defect; one damaged badly enough that it no longer keeps grit and water out is a major defect and a failure, because the joint underneath is already on borrowed time even if it is still tight today. Most joints last well beyond 100,000 miles provided the gaiter stays intact.

How much play in a ball joint is allowed?

Slight play in a steering or suspension ball joint is a minor defect, and excessive play is a major defect and a failure. Where a joint is worn or damaged badly enough that it is likely to separate, such as a fractured housing or a missing split pin or castellated nut, the grading is dangerous and the car should not be driven away from the test.

What does a worn ball joint sound like?

A knock or clunk from the front when turning at low speed or crossing uneven ground is the usual sign. The steering may also feel loose around the straight ahead, with a dead spot before the car responds. A squeak or creak from one corner as the suspension moves normally means the joint is running dry after its gaiter split.

Can I replace a track rod end myself?

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 anything, and have the tracking reset afterwards without exception. Lower ball joints are harder, since many are pressed or riveted in and only sold as part of a complete arm.

How much does it cost to replace a ball joint?

A track rod end is £15 to £35 in parts with under an hour of labour. A lower ball joint pressed into the arm means £50 to £120 for a complete arm and one to two hours to fit. Both sides together, or a car where the joint is integral to the hub carrier, costs most. A four-wheel alignment at £40 to £70 afterwards is part of the job.

Cars this happens to most

Of every model with at least 2,000 tests in the DVSA data, these record ball joint worn on the largest share of their MOTs. Across all of them the typical rate is 2.0% of tests.

1. Renault Trafic12%

   12,568 times in 108,021 tests

2. Vauxhall Vivaro11%

   20,301 times in 182,252 tests

3. Ssangyong Rodius10.0%

   261 times in 2,620 tests

4. Hyundai Veloster9.9%

   243 times in 2,457 tests

5. Nissan Primastar9.6%

   808 times in 8,383 tests

6. Renault Grand Modus9.4%

   262 times in 2,780 tests

7. Chevrolet Aveo7.6%

   558 times in 7,366 tests

8. Nissan NV3007.4%

   172 times in 2,311 tests

A high rate here is a property of the fleet as much as the car: these models skew old, and almost everything fails more with age. It is a reason to check the item on a used example, not proof the model is badly built. Models with fewer than 2,000 tests are left out because a rate drawn from a few hundred cars moves too much to rank.

Pass rates for every make and model →

Other common defects

• Direction indicator not working
• Stop lamp not working
• Lamp of the wrong colour, position or intensity
• Brake pipe corroded
• See all defects →