S6 4.2 Manual Conversion


Registered User
Hey guys would really appreciate some advise.

So far I've had the timing belt, water pump and thermostat changed along with a full long life Bosch Service. I've also fitted Bilstein Lowering Coilovers with some lovely AEM S4 Avus 18" Alloys. German plates to finish off the look.

I also went to STADT to get a Revo Stage II remap and a new exhaust. But now with the increased BhP the gearbox is slipping and its bugging me. I've been quoted silly money for a gearbox service and repair. Plus I've heard horror stories once the "sealed for life" box is opened. So how much will a Manual Conversion be? And where is the best place to go? The name Unit 20 keeps coming up but I've never used them. Thanks in advance fellas.

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"Stick a V8 in it!"
Staff member
VCDS Map User
Its surely worth chucking oil and filter in it just to see what happens. If the oil level is low, then a change and a new filter might well sort it, but if its run for an extended time like that it'll probably be too far gone. Realistically though theres nothing to lose is there? If it doesnt fix it, its still broken. If it does fix it then great.

These sealed for life boxes are a farce. Even the newer 6 speed boxes are having similar issues, and the stupid thing is ZF actually state a 60k service interval for them, whereas Audi and BMW etc all claim they are "sealed for life". Its just the usual thing with modern cars. Everything lasts so well, that infact the manufacturers are doing things to artificially limit their life span. The long life servicing on the engines is the same story.

Hairless wonder

Registered User
My s6 is also down a gearbox, was quoted 2.5k for a rebuild, so spoke to Paul I think his name was, at The firm in Camberley who said it would cost considerably more. I have book marked a few American websites who detail the swap and there's even a company who supply a kit..... Will post a link when I get home.

Have you spoken to anyone at unit 20?


Registered User
A diy rebuild of the auto can be done successfully. I did mine for about $1k in parts (w/o torque converter rebuild or replace) and it works awesome so far, about 2k on it since rebuild, intimidating but do-able.

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