vibration as 35mph+

[carl55]

I got my car MOT done two weeks ago, it passed with no work need doing. And it is a 53reg 2.0fsi se and on Saturday i started to get a vibration which seemed to be coming from the wheels so i took it back to the garage today and they thought that the balancing was out. So i got the balance on the front done and drove down the road and was still the same, so went back and they took it for a test drive and they thought it was from the back wheels and put it on the ramps and found two big screw heads sticking out the back tyre and told me that they could be causing the vibration. They did not stock my tyre as it is 225/40R18 and would have to order one. i went elsewhere for it got one and after driving away still a vibration. The car starts to vibrate at about 35 to 50mph when you have your foot on the accelerator, but if you take it off it stops and when you put it back on between those speeds it starts again.If you put your foot down and boot it it does not do it ether, any help or info on this problem much appreciated thanks Carl.

[churp]

sounds very like wheel balancing problem as this is around the speed when wheel balancing comes into play. if you can feel vibration through steering wheel, most likely to be front wheels, if through whole car, ie felt through your bum, more likely to be rear.
other things to consider is a bent rim, flat spotted rim, etc as no amount of wheel weights can cure that. rim damage is normally caused by pot holes, kerbs etc. or loose wheel or one that hasnt be seated corrected on hub.
if not wheels, could be diff or driveshaft issue, only a guess though.

[carl55]

Just took car to Audi specialist and the car was not vibrating on the way don't know but maybe might have something to do with transmission fluid when its hot or something else when hot as the garage in not even ten minutes away but that is me just hoping it will be a cheap fix but will find out when they phone me tomorrow.

[OddBallBoy]

Apparently with certain tyres, just normal tyre wear can sometimes cause this - the edges of the cleats on the tread can start to wear off on one side more than the other and give a slight vibration. Do a few searches on here about tyre wear and vibration as I've seen it mentioned in numerous posts before. Does it behave differently on different road surfaces? Have a look at the tyres - are the cleats wearing evenly?