The rubber boot protecting a constant velocity joint has split. Once it's open, the grease flings out and road grit gets in, and the joint itself starts wearing rapidly — that's what causes the clicking on full lock people describe.
Wording as it commonly appears on an MOT certificate: “Constant velocity joint gaiter damaged so that it no longer prevents the ingress of dirt”.
What does it mean?
The rubber boot protecting a constant velocity joint has split. Once it's open, the grease flings out and road grit gets in, and the joint itself starts wearing rapidly — that's what causes the clicking on full lock people describe.
How serious is it?
Usually recorded as: Major. The tester assesses the actual vehicle on the day, so your certificate is what counts.
What normally causes it?
- Age and perishing of the rubber
- Grit trapped in the folds cutting through from the outside
- A clip that's failed and let the boot work loose
What a mechanic would check
Look for the tell-tale spray of grease around the inside of the wheel arch — that's usually visible before the split is. Then I'd turn the wheel to full lock and inspect the boot all the way round, and listen for clicking on a slow full-lock turn, which tells you the joint is already worn.
What might need replacing
- A gaiter kit with fresh grease, if the joint is still good
- A complete driveshaft, if the joint is worn or clicking
Can you still drive it?
It's a failure. Caught early it's a cheap boot; left for months it becomes a driveshaft. The clicking noise on full lock is the deciding factor — once that starts, the joint is already on its way out.
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This is general guidance from a UK mechanic, not a substitute for a physical inspection. Only the tester who inspected your vehicle can confirm what was recorded and why.