6 Speed manual conversion (hopefully)

[SharkGill]

I’ve just taken delivery of a 01E 6 speed manual gearbox. Could well be out of my depth here. The last time I did anything like this was when I stuck a MK3 Golf GTI engine into a T25 Transporter (don’t ask why). Any wisdom and insights into how to achieve this would be greatly appreciated. My biggest concern is the pedal box. I hadn’t considered the lack of space for the clutch pedal before I committed to paying for the gearbox and driveshafts.

[Ronin]

I worked on 2 manual swapped s8's in UK, so it has been done

[SharkGill]

I worked on 2 manual swapped s8's in UK, so it has been done

thats good news for me. Any pics of the pedal arrangement as thats the only thing stressing me out at the moment, that and the gearing of the 01E I've bought. I believe it's an ENV code

[MikkiJayne]

Sorry, I wrote a reply to your PM and forgot to press send

Unfortunately you're going to have to figure the clutch out from scratch. There's almost nothing published on how to do it because its very difficult and there are only a few in existence. I didn't take any pics of mine and you can't see it when its installed, but I wouldn't recommend trying to replicate anyway it because it still doesn't work like factory even after hundreds of hours invested in it. There's so little room to get everything in there, everything is a compromise. If you have big feet, pedal spacing also becomes a problem because of the bulge in the tunnel. I had plans to perfect mine and make a bunch of them to resell, but in the end its not good enough to sell to people for the 4-figure price tag it would require to be worth it.

While I love mine dearly and its the best mod I ever did to it, it has been an ordeal to get there and still isn't perfect (or repeatable) after thousands invested and 3+ years refining it. People who think its cheaper than rebuilding the auto are unfortunately in for an very unpleasant surprise.

Your ENV is from a B6 Audi A4 2.5TDI, which is a little too high geared for an S8. 1-5 will be close to the original auto gearing, but 6th will be like mega overdrive and will do 1800-2000rpm at motorway speeds. Great for fuel consumption, not so much for accelerating You'll need to change down to 5th or even 4th to swiftly get past things, unless you cruise at like 120+ in which case its fine



You've probably already noticed it has the small 88mm output flanges, but I think Mario has 130mm flanges to match the D2 front shafts so those are easy enough to swap over.

Watch out when bolting D2 gearbox mounts to the side of the ENV. Later versions of the 01E had different spacing on the bosses in the castings so need spacing out with washers so the D2 mount bolts up. They also didn't always use all the mounting holes so you may need to tap some of them out to M10.

One other thing to note with this gearbox is that the D2 original shifter that Mario has won't fit it as the casing is slightly different and the lever which goes side-to-side doesn't clear. You'll need to extend either the B6 A4 shifter that goes with the gearbox, or use a C5 A6 shifter which is almost the same. They mount differently to the original D2 shifter but its easy enough to make a frame to bolt them to the D2 tunnel. I'll see if I can find a pic of one of those as they were used in the D2 5 speed manual so a factory piece exists for that, albeit unobtanium so you'll need to copy it.

See if Mario can find you original gearbox cooler lines. They will bolt up to this and the D2 rad for a nice easy solution. The ENV has the larger sump and greater oil capacity for better cooling, same as the original S8 version, which is nice.

Oh, and it has a 3.889 final drive (35/9) so you need to change the rear diff in an S8 to either the B6 ETS code that came with the ENV gearbox, or DUP / EUT from an A8 3.7, but those at least are bolt-in.

Pull the lower dash and spend some time lying in the footwell looking up at the mess in there. If you still want to try it, pull the rest of the dash and work out a solution. Good luck!

[HPsauce]

Ten cents worth from me as a total amateur with no intention (or skills) to do a manual conversion on a RHD S8, but bear with me....

I don't know what the actual major issue is with fitting a clutch; the footspace is tight, so no footrest or even big feet, or is it space above to mount a pivot and master cylinder. Or something else? BUT.
Years ago I used to regularly drive a friends ancient Morris Minor around London that had been converted by a previous owner for hand controls due to disability. One clever addition it had (among many) was a clutch servo and I gather these are readily available, though maybe aimed at larger vehicles?

So, if you're being really clever, how about a small (hydraulic?) foot pedal (yes I know that's a tautology) without necessarily a long lever, supported (somewhere else) by a servo on the slave that then operates the clutch master? Maybe a bit "off the wall" but breaks down the problem?
You might end up with something a bit like the infamous Citroen "brake button" or maybe even more like an F1 clutch?

[SharkGill]

Sorry, I wrote a reply to your PM and forgot to press send

Unfortunately you're going to have to figure the clutch out from scratch. There's almost nothing published on how to do it because its very difficult and there are only a few in existence. I didn't take any pics of mine and you can't see it when its installed, but I wouldn't recommend trying to replicate anyway it because it still doesn't work like factory even after hundreds of hours invested in it. There's so little room to get everything in there, everything is a compromise. If you have big feet, pedal spacing also becomes a problem because of the bulge in the tunnel. I had plans to perfect mine and make a bunch of them to resell, but in the end its not good enough to sell to people for the 4-figure price tag it would require to be worth it.

While I love mine dearly and its the best mod I ever did to it, it has been an ordeal to get there and still isn't perfect (or repeatable) after thousands invested and 3+ years refining it. People who think its cheaper than rebuilding the auto are unfortunately in for an very unpleasant surprise.

Your ENV is from a B6 Audi A4 2.5TDI, which is a little too high geared for an S8. 1-5 will be close to the original auto gearing, but 6th will be like mega overdrive and will do 1800-2000rpm at motorway speeds. Great for fuel consumption, not so much for accelerating You'll need to change down to 5th or even 4th to swiftly get past things, unless you cruise at like 120+ in which case its fine



You've probably already noticed it has the small 88mm output flanges, but I think Mario has 130mm flanges to match the D2 front shafts so those are easy enough to swap over.

Watch out when bolting D2 gearbox mounts to the side of the ENV. Later versions of the 01E had different spacing on the bosses in the castings so need spacing out with washers so the D2 mount bolts up. They also didn't always use all the mounting holes so you may need to tap some of them out to M10.

One other thing to note with this gearbox is that the D2 original shifter that Mario has won't fit it as the casing is slightly different and the lever which goes side-to-side doesn't clear. You'll need to extend either the B6 A4 shifter that goes with the gearbox, or use a C5 A6 shifter which is almost the same. They mount differently to the original D2 shifter but its easy enough to make a frame to bolt them to the D2 tunnel. I'll see if I can find a pic of one of those as they were used in the D2 5 speed manual so a factory piece exists for that, albeit unobtanium so you'll need to copy it.

See if Mario can find you original gearbox cooler lines. They will bolt up to this and the D2 rad for a nice easy solution. The ENV has the larger sump and greater oil capacity for better cooling, same as the original S8 version, which is nice.

Oh, and it has a 3.889 final drive (35/9) so you need to change the rear diff in an S8 to either the B6 ETS code that came with the ENV gearbox, or DUP / EUT from an A8 3.7, but those at least are bolt-in.

Pull the lower dash and spend some time lying in the footwell looking up at the mess in there. If you still want to try it, pull the rest of the dash and work out a solution. Good luck!

This post is pure gold, thanks MJ. I haven't been active on forums in a very long time but this reminds me of the thrill of learning something new and then not being able to wait to get out to the car to do the work. I've bought a spare RHD pedal box to help me visualise and try and come up with solutions.
I get confused with gearing talk but I do enjoy dropping down to third and redlining when passing on the motorway in one of my other cars, purely to hear and feel the car at that range/speed. So based on that, the ENV box will proabably be ok for now.

[SharkGill]

Ten cents worth from me as a total amateur with no intention (or skills) to do a manual conversion on a RHD S8, but bear with me....

I don't know what the actual major issue is with fitting a clutch; the footspace is tight, so no footrest or even big feet, or is it space above to mount a pivot and master cylinder. Or something else? BUT.
Years ago I used to regularly drive a friends ancient Morris Minor around London that had been converted by a previous owner for hand controls due to disability. One clever addition it had (among many) was a clutch servo and I gather these are readily available, though maybe aimed at larger vehicles?

So, if you're being really clever, how about a small (hydraulic?) foot pedal (yes I know that's a tautology) without necessarily a long lever, supported (somewhere else) by a servo on the slave that then operates the clutch master? Maybe a bit "off the wall" but breaks down the problem?
You might end up with something a bit like the infamous Citroen "brake button" or maybe even more like an F1 clutch?

Food for thought. I bought a spare pedal box for under £20 so hopefully I can experiment/learn on that

[HPsauce]

Indeed, but that's why I'm trying to "think out of the (pedal) box".
IIRC everything I've read about this topic has talked about the difficulties of fitting a (conventional) pedal box in a RHD A8/S8. Fixating on that seems to hit really tricky obstacles.
But can you just remove the footrest and put "something else" there to operate the clutch "by other means"?
The answer is obviously yes, but the challenge is to find a solution that is not too complex/expensive, ideally uses minimal bespoke hardware and gives you the "feel" you need.
I'm old enough to remember cable clutches and brakes (not to mention drum brakes, freewheel gearboxes and other things you'd hate on a modern car).

[MikkiJayne]

Fixating on that seems to hit really tricky obstacles.

Very much so.There's a spare bit of spindle which seems perfect for a clutch pedal to hang from, but then there is nowhere to put the master cylinder for it to actuate.

There's a pull-type master cylinder available from AP racing which seemed like it might be viable, but they are £400 each and available in multiple different sizes, so thats an expensive experiment!