The tyres and balance are fine. That was the first thing I thought of. There is definate knock from full lock to full lock. The wheel wobble is different to when the balance is out, it doesn't come and go at certain speeds, its slightly heavy and the steering wheel needs to be held off centre slightly and there is a slight vibration throught the steering. I was expecting bushes etc on the MOT, the guy had a good look because he could hear the knock as he was moving the car around the garage to get it on the ramp. It must be a non MOT item, but what? Braking is fine. Thank you for your help.