Got access to a ramp Saturday (thanks Bill)... took me a while to get motivated tbh as after a few attempts at trying to sort the gearbox/clutch situation had not gone well and lets face it, dropping a quattro box is not the most fun thing in the world to do..
As is the way of my luck so far the day started well... and by well I mean one of the subframe bolts pretty much fell out when I unscrewed it... seems that the subframe fixing has seen better days...
...disappointing...!
...will deal with that later... so... here we are again... the R32 box is out...
The R32 box (left) and the 4-Motion DRP box (right)...
Took the slave out from the R32 box...
Brand new from the last time the box was off... and still getting damaged some how... so Alex and I took a little time to do measurements between boxes, plates, DMF's etc.... the only measurement I couldn't do at the time was to check flywheel face to block distance as all the other measurements seemed to be the same between a 20v and this setup...
We then looked at the plates themselves... there was evidence of the nose of the Sachs plate having touched the inside of slave which would explain the damage and cause of the slaves getting wasted... what was not easy to deduce is to why the nose would even be doing this in the first place as this setup is tried and tested in 20v's and our measuring suggests that everything should just work...
Alex grabbed an old plate that was kicking about the workshop and I noticed that there was a machined rebate in the nose that mine did not have.... I didn't take pics of the nose of mine sadly but here you can see the rebate on the old plate...
Took some measurements of the inside of the slave guide sleeve and it was around 0.5mm smaller than the nose of the Sachs plate so Alex put the plate on the lath and tuned a rebate into the nose of it... the plate now sits flush to the release bearing face (would never get that close in use due to the cover plate fingers and included a little wiggle room... it actually didn't require much material removing so won't compromise the integrity of the plate..
I didn't take any pics for some reason but tbh its not really a DIY mod as using anything other than a lathe could cause problems if not perfectly round...
With that done I refitted the clutch and then the 4-Mo box... I used the transfer box from the 4-Mo too as it kinda made sense to keep them together.. the R32 transfer box will be kept as a spare
...and now for the job I have been putting off.... ideally I would weld a replacement captive 'nut' in but that would require pulling up the carpet and no doubt a little cutting the floor about to sort out so I went for a helicoil on the basis there was an M12 kit at the workshop and whatever I did would be better than no thread at all...
Drilled and tapped.... tapping was a little hard going... had to back out a few times to clean off the swarf as the usual cut and back motion was enough... was worried it would hang up and either snap the tap or literally pull the fresh threads back out!...
...however it went ok in the end and got a helicoil in...
Torqued up the subframe bolts to 100nm +90 (ish) and was a little more cautious on the helicoiled bolt but it took as much of the 90 degree as I felt comfortable doing and didn't feel like it was 'going soft' but time will tell of course and I plan to do something better next year (assuming it hasn't failed in the mean time)
All back together and filled with (yet more) gearbox oil... bled the clutch and all felt good...
Got the old girl re-dressed and backed her out the unit...
Had to get some fuel on the way home and popped to the Shell garage... they are doing roadworks on the roundabout there and they must have used some loose road filling material as it was dark and I rode over a trench crossing the road with a bang big enough that it opened my door!... I honestly thought I was going to find dents in the bonnet from front strut tops!!
Thankfully it seems there were no dents and the wheels still looked round! phew!..
I can report that I managed to drive home with no clutch issues at all... I even had a bit of a spirited burst changing up and down through the box with ease... who knew that could be a thing! lol..
Jury is still out... I need to put some miles on before I am 100% convinced but... I now believe the Sachs plate and 4-Mo DMF is most likely the cause of my problems so far in so much that (and this is informed speculation) the 4-Mo DMF sits the clutch plate a little further away from the engine (closer to the box/slave) and the nose of the Sachs plate while not an issue on the 20v application its designed for is just long enough that it interferes with the slave...
A std clutch plate does not protrude like the Sachs plate does so would not be an issue if using a std friction disc... the machining of the nose appears to have fixed the issue here and the R32 gearbox issue with the input shaft play was a bit of a red herring... there is more in/out play than there should be but its no different to any of the other boxes I have since looked at...
Hopefully the clutch is sorted out now, I am not really too surprised that I needed to do a little extra work to get all the clutch parts to work... its not the first time that a mix and match of parts needed fettling to work but at least I now know (and of course so do you)
Time to actually drive the car and I need to get a front alignment done now the subframe is not due to be off (hopefully) anytime soon...
Last main part of the turbo conversion should be sorted soon... ... I was going to use the R36 shells that everyone tends to use but ACL do coated big end bearings so will probably go with those...
There are a few other little things to sort out like downpipe bends and other stuff but these are all in hand...
I need to get the hot side separated on my GT35 so I can clock it correctly but this is proving a little tricky as its pretty much holding in there... I don't want to apply loads of heat in case I heat it up in the wrong place and nuke the bearing packs... all jobs for the winter though
<tuffty/>
