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D2 - Transmission Gearboxes, diffs, drive shafts.

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  #1  
Old 12th November 2014, 10:17 AM
Dave McB Dave McB is offline
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Default 5hp24

Im considering selling the S8 and buying an RS6 in its place.

From what iv gathered the box is basically the same.

What im curious to find out (this is the parts person in me here)

What is the difference? Ratios? Programming?

OR

are they exactly the same?
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  #2  
Old 19th November 2014, 05:31 AM
mik15 mik15 is offline
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i also have an RS6 C5 and though the gearboxes have the same code, 5hp24A, there are some differences, at least the ones i am aware of:

- torque converter is larger
- the bell housing of the torque converter is obviously larger
- definitely programming is different, the A8 ones is smoother and gear changes take place at a lower rpm


Apart form that i do believe that the internals, clutch packs and drums, etc..are identical. Gear ratio is probably different, haven't tried the A8's top speed, but the RS6 can do close to 245kmh in 4th gear and then goes into 5th gear.

As a conclusion, they're are not identical and not interchangeable(without modifications).
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Old 19th November 2014, 09:12 AM
Dave McB Dave McB is offline
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I hadn't planned changing them - I was curious as to what the differences were - Im seriously considering an RS6 - but the chances of gearbox failure are far higher than the S8 - I wondered whether the same box was used or whether the RS6 variation was meant to be 'stronger'
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Old 19th November 2014, 09:27 AM
mik15 mik15 is offline
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it definitely was meant to be stronger, and it was, holding up 450hp and close to 600NM is far more than the 360 and 420NM of an S8. Problem was tuning which would put even more stress on the gearbox by the increased torque and early ones had a leaking seal on the torque converter which eventually, if undiscovered quickly, would lead to gearbox failure and all that coupled with the rubbish lifetime oil meant planing for disaster .

if you want to get one, look for one which had gearbox and DRC replaced, and you should be ok, those are the big tickets with the RS6 C5, otherwise is just like any other V8 from Audi, apart from brakes, which are quite expensive to replace. Look on rs246 forum and you'll find whatever info you need, but be warned that that power is addictive and comes at a price, once you accept that you're good to go and enjoy it.
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Old 20th November 2014, 08:23 AM
Dave McB Dave McB is offline
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Thanks for the tips

I plan (ideally) to look for one with the coilover change already done.

I work in the motor trade & have a decent relationship with Mackies, so im effectively looking for one with a dodgy box
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  #6  
Old 20th November 2014, 08:42 AM
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Goran Goran is offline
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I would be too scared to risk it, are the next gen RS6's too expensive?
As I sat at MRC chatting to another customer with a RS6 in there having gearbox work done, his comment was those gearboxes are made of cheese
I guess he was having a lot of problems with it.

On the other hand, with the RS6 a manual swap is a real possibility. All factory parts exist including the pedal box from a manual UK A6, and the only major stumbling blocks are custom adaptor for 01E gearbox has to be machined, and ECU has to be professionally re-mapped to ignore that it no longer has to listen to the auto box TCU.
TDI 01E's (the strong ones) are cheaply available in the UK, I got one last year for only £200 just to pinch it's 6th gear, it looked very clean inside.

Last edited by Goran; 20th November 2014 at 08:46 AM.
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  #7  
Old 20th November 2014, 11:19 AM
Dave McB Dave McB is offline
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that's certainly something worth looking at

So effectively, a 6 speed from a TDI A6 could be mated to an RS6?

What clutch & flywheel combination would be matched up to that?
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  #8  
Old 20th November 2014, 01:35 PM
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Goran Goran is offline
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Any A6 (or A4 probably) 01E 6-speed 4WD gearbox 2000 or younger would do.
I prefer the A6 Tdi boxes because they have a nice 0.56 ratio 6th gear. There is no sense running at close to 3000rpm at 70mph with that much power. The Tdi 6th takes it down to close to 2000rpm. My S8's mpg went from around 25mpg to around 31 for a motorway run just from the 6th gear swap.

There are some sites with lots of info about 01E, I will find and post links. If I remember correctly any 01E 4wd from year 2000 onwards has a wide 1st gear and 'flex' main shaft which enables it to handle a lot of torque. All the B5 S4's running huge torque over 500lbft don't have problems with their 01Es handling that torque, its a very tough gearbox.

I think (from the pictures) RS6's 4.2 engine is a 10-bolt to flex plate. You would either need a custom flywheel or perhaps the pre-face S8 or S4 flywheel might fit, I believe those are 10-bolt too.

You would need a performance clutch I'm guessing, I don't think the stock S8 or S4 clutch from the dealer will handle the amount of torque the RS6 can deliver. There are loads of performance clutches out there to chose from, AWE, JHM, etc. That may take a little researching to see which ones fit and which ones are good.

Here is one RS6 conversion:
http://www.rs6.com/showthread.php/22...d-RS6-with-01E

And it looks like MRC have done a RS6 conversion to manual too. I heard Unit 20 did one also.
http://audisrs.com/viewtopic.php?t=47211&start=0
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  #9  
Old 20th November 2014, 09:54 PM
Dave McB Dave McB is offline
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I actually stumbled upon a full conversion kit whilst looking for something else today at work. 👍

Just need to get rid of some of my fleet before I have space for a new car 😂😂😂
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