This is my first PDK car, and I've noticed some noises coming from what I can only assume is the gearbox. Under light load it sounds a little like gear nashing, maybe a little grinding. At a stop, it sometimes sounds a bit like a throwout bearing on a normal manual car or a twin disc clutch rattling.

The dealer I took it to seemed to think these were normal noises for a 991 TTS gearbox. Is this anything to worry about? The car is a CPO car but I've been considering an exhaust + tune and want to sort out any possible transmission issue prior to voiding my CPO warranty..

They did reflash the PDK and add a quart of fluid while it was there, but nothing has changed noise wise.

 

Only way to tell is to drive another car similar to yours. I dont think the noise should be there.

 

Neither the exhaust nor the tune should void the CPO warranty on your transmission or really any other part of the car. If you're worried make sure to go through a mod friendly dealer. I had no issues with my exhaust + tune + ICs and my CPO through my dealer.