Mike D.

Anyone experience this? I've been noticing it recently - almost like the differential isn't working properly while making a sharp turn. It's faint but noticeable. It otherwise drives fine and has no faults.

142 guy

Do a search. There have been at least two or three recent threads on the A4 B9 and A4 B9 allroad forum discussing the AWD (center) clutch noise and differential noise. For sure there is an Audi technical service bulletin covering the problem with the AWD center clutch.

blorzoga

I just picked my 2017 up from the shop with the thumping problem. It is from the differential and there is a TSB for it. They replace the fluid, drive it then check for metal filings. I think they did it twice. No filings (if there had been it would have meant a differential replacement (~$1,100)). Mine did not need to be replaced. The rumbling is gone, so are 500 of my hard-earned dollars. If you're under warranty get it checked out and it should be covered. Tell them there's a TSB. I don't have the # offhand but will get it an post later.

mgwooley

I had this exact issue. Get it checked out ASAP before it gets worse. I'm in need of a new center diff / diff clutch pack as a result. Luckily I'm covered under warranty.

KevinGary

Try changing the fluid in the center differential. Audi’s claim of lifetime fluid is dubious.

Jack Foulard

any Link to this TSB?

142 guy

Circular (nhtsa.gov)

Mike D.

Ughh... I forgot about this post. Took it in - tech of course found nothing wrong aside from a loose strut brace, which there is also a TSB for. Anyway, of course it's still doing and have to bring it back. I downloaded the TSB above and will show them this is the exact issue. Thanks!