I noticed something today that I never noticed before. When traveling at say 50 mph and either downshifting into second from third or putting the car in neutral letting out the clutch then downshifting into second at 50+ I get a loud thump coming from the back of the car...I tried the latter just to see if I actually had to be coming out of third gear. Rev matching before I downshift helps very little but the thump is still there.

I would greatly appreciate everyones help to tell me if its normal or not, and what it might be.

Thanks

07 997S with about 14k

 

I had a thump once years ago and it drove me nuts . It ended up that the lock nut bolt was behind the passenger seat .

That may not be your case but if you'd like to have the car looked at in my area PM me as you are not far from me.

 

Thanks Larry....did your noise occur during downshifting to and what is a lock nut bolt, is it for the tranny?

 

Any sudden upshift or downshift with abrupt motion caused the thump . The lock bolt was to remove the tire. In short the loud noise could be something that simple . I hope it is for you.

I do know you have faced a few clutch snags in the past but this may or may not be related.

 

Take everything out of the car (trunk, glovebox, CD's, phones, change, the lot) and try the exercise again. If you still get the thump then it's time for a trip to the stealer.

 

Thanks guys...just removed everything from the car and the noise is still there and only when downshifting to 2nd from 3rd or even neutral and only at speeds above 45 mph...the faster I go above 45 the louder the thump is when downshifting...it's definetly related to down shifting and just when the level starts to go into second. I'll be at the dealer tomorrow and see what the heck is going on...I hope its not the trans : (

Thanks again.

 

Since it appears to be clutch or gearbox related any tech savy folks here care to offer any thoughts?

 

Ok, just found this thread on rennlist: http://forums.rennlist.com/rennforum...tch-thump.html apparently the thumping is a fairly common issue and mine is getting worse by the day.

I also found that there is a recall from porsche about a shift cable bracket that comes loose..no idea if that contributes to the thumping sound.