uncensored06

When I put my 2011 D4 into reverse, I hear a "winding" noise while backing up. It has 198k miles....and from my knowledge the transmission fluid has never been changed. Any other obvious culprits? Drive axles?

gk1

Has it not always done this? i.e This is a "new" sound you are describing?
Reverse gears are straight cut instead of helical like forward gears and make noise.

uncensored06

I have always heard some winding maybe I'm just thinking that is more pronounced now. I'm not sure if temperature has anything to do with it....or the fact that I know that the transmission fluid has never been changed. That would be a DIY task that ainwoukd need to figure out how to do.

gk1

Just be careful. Changing ATF trans fluid for the first time on a decade old car can sometimes be considered a no-no and cause more issues than it is worth. Investigate it yourself very thoroughly before making the decision.
Something about new fluid cleaning agents dislodging debris that then causes issues elsewhere.