Originally Posted by Jeffstoff

First of all, just want to thank you all for your input on this issue. This thread saved me a lot of $ and if I had only found it sooner, it would’ve saved me about $400 in diagnostic fees as well.

I have a 2018 b9 6-speed manual, so with the ocx type mentioned above. I currently have 59k miles and bought the car at 19k.

I started noticing the noises from the drivetrain/buckling mentioned above around the 49k mile mark. I will say that for me, it was difficult to pinpoint where the buckling was coming from. Felt like it wasn’t really specific to one area, just underneath/in the drivetrain in general.

At first, the problem only presented itself when the wheels were turned while pulling out in first, up a hill. This was concerning but I shrugged it off as it was fairly minimal. Then at about 57k miles, about two months ago, this started to happen without the wheels being turned, and basically every time I pulled out of first gear.

I took it to a German motor works place in town and they basically gave me zero new information(told me there was play in both the tranny & rear diff), told me to take it to the dealership, and charged me $185. I took it to another German service place that specialized in Audis, and they quoted me $950 for the awd coupler flush x2 with the computer reset. They also gave me pricing to replace the awd coupler, which would’ve been $3,800. They recommended the latter of course, saying that the flush was a gamble that may not work. $220 for the diagnosis.

At that point, I was seriously considering just biting the bullet and having them replace the thing, but also wanted to read into it some more to make an educated decision.

Then I found this thread early last week(and Sjorge’s words of wisdom convinced me to do the flush).

I purchased 3 bottles of the transfer oil (g 055 515 A2) and yesterday I put the car up on ramps, found the awd coupler(directly behind the tranny), and drained the oil. I didn’t see any metal clumps, but there were very small metal shavings/sparkles that I could see rolling around in the drain pan.

As soon as I pulled out for my first 50 mile drive, the buckling was still present. By the end of the drive though, it seemed like it was a little better. Encouraging. I repeated the process(drain and refill) once again and drove it another 50 miles. This time I felt no buckling at all and the problem seemed to be gone. I had extra oil, so I decided to do it a third time, as it was a fairly quick process. And I wanted to make sure I got all of the metal shavings out of there.

I’ve driven the car about a hundred miles since the three flushes yesterday and the problem seems to be completely resolved. Has not buckled or skipped a beat once!

I haven’t reset the computer, and as Audi quoted me $250 just for that, I’ll likely skip that part of the process unless someone here can convince me that it’s absolutely necessary.

By the way, you could probably get away with buying a single bottle of fluid for this process, but I recommend buying 2 to be sure. I did the flush 3 times and used about a bottle and a half total. I also used a bit extra each time with the drain plug off to flush the system.



TLDR: if you’re experiencing this issue, do the flush x2 or x3 for good measure

cheers!

Originally Posted by bavarianpastime

Are these the drain and fill plugs?

Originally Posted by Bobert

I've got a b9 a4 6 speed manual. Just got my ultra awd unit replaced under warranty. And now my car is worse than before I took it to the dealer... don't know what to do now

Originally Posted by Bobert

Freaking dealer had it for almost 3 weeks and did almost 8k in repairs... and now it's worse. I'm hesitant to take it back but yeah I am. I have a feeling it's just the center support carrier bearing causing the rhythmic vibration all along