Knocking/Thumping from rear when pulling away.

[jimbo1234567]

subframe mounts?

[sfrs4]

you say worn tyres on the back but less so on the front? should they not be all the same tread depth? i was always led to belive that on a four wheel drive car there's a possibility of winding the diff's up with un equal rolling radius as some wheels are spinning faster than others, this could also explain the cyclic occurance, wind up a little then release a little. just a thought.

[Contigo]

Nah not sure that's true on the torsen diff or any diff for that matter. It's impossible to have even wear all around as the front generally wear quikcer than rears.

[GregorFuk]

It has Toyo's on the back and Michelin's on the front (put on be previous owner), the Toyo's have worn away very quickly. Think the rolling radius issue is only a problem on cars with a viscous diff, I don't think mechanical diffs react in the same way. Anyway, it's getting looked at today by the local VAG specialist. I'll be sure to update on the cause of the problem and add to the RS246 knowledge bank.

[neily]

I'll be sure to update on the cause of the problem and add to the RS246 knowledge bank.

So any updated news on this ?

[GregorFuk]

Yup. It was the tyres. I took it to the local VAG specialist who could find nothing mechanically wrong with it. They suggested I put some fresh tyres on the back and see what happens. Sure enough, two new Michelins on the back and the knocking has gone. Must have been the difference in rolling radius after all.

[neily]

great news. It sounded expensive for a moment......