[Oldcarguy]

I have a grinding sound from the transaxle/drive train when reversing. It’s cyclic (grind, quiet, grind, quiet...) and varies proportionally with my reversing speed. It’s done it ever since I’ve owned the car. Recently changed the trans fluid with Porsche fluid and no change. I didn’t find any metal in the old fluid and the correct amount drained out. No problems shifting, no noise in forward gears, no vibrations, no cv clicking.

It’s not a rock in a brake shield, nor a problem with the e-brake. I just put on new rotors and pads, so I know everything’s clear for the brakes. 107,000 miles on the car.

Any ideas???