Cracked rear differential!

[djk949]

Hi all,

Didn't want to post my first post on this note, but wanted to see anyone else has had this issue...

Had Haldex oil changed at dealer on my 2009 A3 2.0t quattro and then 12 days later my car makes a horrific clunking crunching sound from the rear and all wheels stop. Turns out the rear diff was cracked, fluid was black and wheels locked up. Lucky for me, my warranty runs out 10k miles from now. So, all is covered.

I found a post in the UK about a similar situation except his died 2-3 days after the Haldex oil change.

Coinicidence? Or am I crazy?

[JRutter]

I have heard of mechanics mistakenly draining the "lifetime" fluid from the rear diff portion of the Haldex unit and only topping of the Haldex fluid in the center diff clutch pack. Of course, no one wants to own that one, so it becomes a part failure that just happens to coincide with Haldex service...

[djk949]

So, the rear differential fluid does not get changed out with the Haldex oil change? By "lifetime" do you mean it never gets changed?

[JRutter]

Right - There are two separate parts of the Haldex unit and the fluid is different in each section. The Haldex clutch pack needs their special magic fluid. I think that the differential fluid is typical synthetic gear oil, but do not have firsthand knowledge of this. And I believe that the gear oil does not have scheduled maintenance.

[LWNY]

Audi should have gone with the Haldex w/eLSD. The whole shebang in one unit, no 2 parts cobbled together.

[djk949]

Also, found that there is a side drain plug, which if used for filling can spring loose a bolt inside the unit...and wreak havoc. So, supposedly only the bottom drain hole should be used for filling and draining. Why did Audi make this so complex? Now, I'm paranoid my car may ditch me by the side of the road at any given time...

[djk949]

So got my car back. Talked to a different mechanic who said this dealership sees this happen every month or so to A3's and TT's. When they do, the unit goes back to Audi unopened (even though they wanted to) and they get shipped a new one. Audi obviously is investigating this yet no TSB has been announced or any extended warranty. This may be the first and last Audi I ever buy.

[ChrisGS4]

It sucks but things break on every brand or car. How the company handles problems is what matters. I would assume after complete self destruct happens it would be awfully hard to prove any mixup with the oil.