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Mechanical clunk under acceleration
Posted: Mon Oct 12, 2009 1:34 pm
by mbelle
Had the rear tyres changed a few days ago (fronts to be changed very shortly, but for the first time ever, I now have different rears to the fronts).
Since having them done, under even slight acceleration, mainly in second, I feel what seems to be tugging, as if one rear wheel was gripping better than the other - no ESP light though.
However, just driven with windows down today and it appears to be what sounds like a mechanical "clunk", sounding like it's coming from the rear... anyone had any similar feelings/sounds or may have any ideas?
RE: Mechanical clunk under acceleration
Posted: Mon Oct 12, 2009 1:58 pm
by Nige_RS4
Maybe one of your plastic drop links snapped when they lifted the back of the car up to remove / refit the tyres? Or the rear exhaust hanger is another weakspot.
RE: Mechanical clunk under acceleration
Posted: Mon Oct 12, 2009 3:28 pm
by mbelle
Cheers Nige - I'm going to take the wheels off shortly and see what I can see for myself anyway.
Other than that, could the diff make said noises...??
RE: Mechanical clunk under acceleration
Posted: Mon Oct 12, 2009 5:56 pm
by Contigo
Diff and also the different rolling radius of the tyres between the two axles.
Read this thread.
http://www.rs246.com/index.php?name=PNp ... light=thud
RE: Mechanical clunk under acceleration
Posted: Mon Oct 12, 2009 7:20 pm
by mbelle
Thanks Contigo; I reckon it's my tyres as well, but am worried it could still be the diff.
I'll get the new ones put on the rear and the rear moved to the front and see if that cures it...
RE: Mechanical clunk under acceleration
Posted: Mon Oct 12, 2009 8:58 pm
by mbelle
What would be the cause of this is though, even if it does turn out to be the tyres...??
RE: Mechanical clunk under acceleration
Posted: Mon Oct 12, 2009 9:26 pm
by dace
Marcus, it is proven that you must change all 4 tyres so there is no adverse stress on the diff. Don't ask me why but if you want my opinion go for 4 new tyres.
Re: RE: Mechanical clunk under acceleration
Posted: Mon Oct 12, 2009 10:02 pm
by rtd
mbelle wrote:Thanks Contigo; I reckon it's my tyres as well, but am worried it could still be the diff.
I'll get the new ones put on the rear and the rear moved to the front and see if that cures it...
the tyres are defo a problem and as a result could have effected the diff.
RE: Re: RE: Mechanical clunk under acceleration
Posted: Tue Oct 13, 2009 7:43 am
by Contigo
Well I'm not sure that is entirely true, I have used different types of tyre on the front to the rear and it's been running fine like that. I've got Conti 3's on the front and Conti 2's on the back at the moment and it ran fine at CC at the weekend.
The rule I've heard is that you should not mix tyres accross an axle but you can between two axle's.
RE: Re: RE: Mechanical clunk under acceleration
Posted: Tue Oct 13, 2009 11:11 pm
by rtd
well according to the two specialists i spoke to they strongly advised me from using different types of tyre on the car - was informed that over time the diff would feel the effects and suffer. pls dont ask me to explain i hardly understood it first time round when it was explained. the same was also repeated by geometery/alingment people.