I have put up with this annoying bumping sound for a few weeks now and as you lot on here are so knowledgable about 300s was wondering if you could give me a diagnostic, this is what happens, when on hard accelleration in first gear i get a little thumping sound coming from behind my drivers seat, but only happens in low gear and only when i,m trying to do wheelspins, sounds like someone is trying to get out of the back ,"gearbox most probably"anyway thanks for any help given.

This is known as wheel hop, due to the design of the 300 rear suspension Anti Squat. Quite Normal my man. To get rid of wheel hop I think you have to upgrade the bushes and Dampers, anyone else with views on this.

i initially thought it was a loose gearbox mount or similar prob,?

Could either be worn subframe bushes or worn diff mount bushes - get them checked out

 

CheerZ,

 

Andy

I'm getting this too. Though i don't try and wheelspin.

 

The key point I picked up on this the back of the drivers seat - definately / exactly.

 

I'm suspicious of the proposhaft centre mount with mine. Haven't done it yet cos that's another 150quid. I've looked at all the rear end bushing on mine, and cant find anything so...

 

Did you fix yours? Help me out?