Testing cv joints

Oh., I'm so glad you asked that, I'm heading for cover.

Howdy Cowboy, as Gaz says above " if it's clicking it's time for replacement " but as you mention that it only clicks a little on full lock then you could inspect the joint and if it appears that it could be dry of grease then you can simply try inserting some CV grease to see if the noise disappears .

If the noise remains after carrying out the grease replacement then the examiner would have to make a decision based on his experience on whether to fail or simply pass and advise.

As yours as you describe is only a little on full lock then it is highly likely that this will not be detected at the MOT test .

MOT testers can and do fail CV ends that are excessively worn on a steerable axle but it will depend on the severity and the steering angle at which the noise occurs.

Do be careful though working as a DIY on a job that I would describe as having moderate difficulty. You need to consider your own and others safety, so take care or leave it to a professional.

You really wouldn't want to drive one that was bad enough to fail MOT 

Well Ian you should at least think about changing that joint before too long. But, as regards the MOT test, in my view they have to be pretty much hanging off before I could call it a definite fail. It's less to do with what noises they make than how much play I can detect between the shaft and the wheel.