Rocket3004

Soooo, my rear propshaft seal is leaking on my 98.5 A4 Q Tip. It's pretty normal for higher mileage cars to do that. Here's the thing, the fluid is in "good" condition. When replacing this seal, should I go ahead and flush out the old fluid and put in new fluid? AT fluid is pretty strong stuff (detergent) and can really clean out the internals of the trans and cause harsh shifting in cars that have never had a flush and have higher miles, and have sort of "adjusted" to the old fluid in a way, from what I understand.

So the question remains... should I have the fluid flushed or not?

My car has 87K miles and from what I know has never had a trans flush (still on original fluid, which the mechanic says is in "good condition" not to dark but not brand new... okay but not terrible)

Joey T

I think. Pretty sure that is a seperate unit with seperate fill.

Rocket3004

What would be the cut-off from sticking w/ it and flushing it out?