brianb8

I have a 2009 B8 A4 avant with the 6-speed automatic transmission. I have successfully added an S5 wheel and activated the paddles. The biggest obstacle was taking apart the airbag from the 4-spoke wheel and stuff it into a cover for the 3 spoke wheel. Anyhow, back to the topic at hand.

Whenever I come to a complete stop and try to continue on my way there is a lag and then a small thunk when the gears engage. I have also noticed when driving for an extended drive on the highway, when I try to accelerate to pass, there is transmission slippage. This only happens after about an hour of driving (and my '11 B8 sedan with the 6-speed doesn't do this). I see this as a potential problem in the future. I have access to a transmission from a 2013 8-speed transmission from an allroad I can see this part number on the transmission 1087137042 .

2 questions...Will it fit and will it work? Current car has about 70,000 miles on it.

Any insight would be greatly appreciated.

Any searches I did on the site were more dedicated to an automatic to manual swap.

Thanks in advance for your insight.

brianb8

This question has left quite a few pondering. Anyhow, between 4 garages, 2 dealers and a number of searches, it would appear that the ZF 8-speed automatic will not work to replace the ZF 6-speed automatic. Connectors are different, apparently half-shafts are different, and I didn't get confirmation on the driveshaft. If it was plug-and-play I would have done it, but there is too much

SMac770

In the US B8, 6spd was 2009 and 2010, 8spd was 2011 and 2012. And it seems the front axles (8K0407271P, but then also lists a 8K0407451FX part number, no idea the difference) and drive shaft are the same. The mounting gear to the engine and to the transmission mount are the same.
Not sure what you mean by different half-shafts. But your 8spd is from 2013 (B8.5), so very likely there could have been more changes during the refresh (front axles part number is 8K0407271AL, but who knows what's actually changed).
I do notice that the 6spd and 8spd in B8 use the same transmission tunnel support crossmember, but that the part changed in Oct 2009, which means our 2009 MY would be the old one. I wonder what was changed, and if the L rev would be physically compatible.

But I'm sure it's not a simple plug and play. If it were, I'd be all over finding an 8spd to replace the 6spd in my 2009. But the output shafts all seem to be the same, and the engine management computer is the same (for a B8.0 8spd); I bet it could be done. But would the custom work be worth it.

brianb8

I could have picked up the transmission for $550, and thought it would be a fun project, but from what I gathered, it may be a lot of work, and I need my car as a DD, so didn't have the luxury of farting around with it for a while. I was told the connectors were different. By half shafts, I meant axles (or half axles).

Oh well, I didn' tthink fo even look to see if the rear diff would need to be changed. I have scrapped the idea for now.

Thanks for your insight.
Brian