Clutch Return Again sorry folks

[mondo2126]

anyone any ideas, had slave cylinder, pipes and master cylinder replaced, problem still recurring, 2nd gear to 8000 3rd to 8000 into 4th no problem,clutch bites at high end of travel as normal slow down and change down pedal sticking on return, clutch bites as soon as i lift my foot off pedal, all theories welcome, works perfect as long as i dont do high revs

[sar]

hmmm it would be nice to get to the bottom of this once and for all.
mine has started doing this for the last 500 miles or so, im on 45000 miles now.its only stuck fully down once and i lifted it back up with the top of my foot then it worked ok, then maybe four or five times where the pedal returned to approx 60% of its travel and i had to lift it the last 40% or so.
for a few hundred miles before it first stuck down im sure i could feel pedal getting slower to return,on spirited driving on a quick gear change you could feel the pedal didnt return as fast as i lifted my foot,it never stuck down at this point just didnt feel right, but as i had read the various posts on here before about the mysterious sticky clutch problem i thought maybe this was it starting and sure enough a couple of hundred miles later first incident of the pedal not fully returning.
loads of people on here have had this problem and have had pipes changed,slave and master cylinders changed and the problem is still there,the only thing that seems to cure it is a full clutch swap.
i read a post on here once where someone said the problem was the sleeve that the clutch release bearing sits on starts to catch and where he had taken his to be repaired said audi had released a revised part that fixed it.
i bought a oem clutch kit for mine but havnt had it fitted yet,i asked my man in tps if the sleeve was a revised part number and as far as he could tell it wasn't ?.

[ArthurPE]

mine's in the Shop having the hose and cylinder done...seems sometimes that resolves it...

but looking at a parts diagram I can see how wear on the guide tube (on which the release bearing rides/slides) would cause it to 'hang up' or catch
it looks like it floats on the shaft and can wear (looks tapered too) http://www.microsofttranslator.com/BV.a ... 2F1%2F2275

this wear could cause the tube to groove making a lip for the bearing to catch on or result in friction due to misalignment, ie, cause the bearing to get 'stuck' on the guide sleeve, and this likelyhood would increase with time as grit, clutch dust, lubrication wore off, etc.

looking at the part (0A2141181) it looks like it may be some synthetic material, not metal? http://www.ebay.com/itm/Porsche-Cayman- ... 0673022487 same as used by Porsche and you can see, not bolted to the housing like the BMW item 1 http://realoem.com/bmw/showparts.do?mod ... g=23&fg=15

my BMW guide tube was steel and bolted to the tranny, it did not ride on the shaft, so could not wear inside, and since it was metal and the bearing was plastic, would not wear on the outside, the bearing would, and in fact get 'looser' or more play and less likely to bind...the Audi would be the opposite, more likely to bind over time...

since the BMW sleeve is fixed, it would be self wiping or cleaning, if the Audi's turns at the same speed as the bearing, this cleaning action would not be as pronounced

it doesn't look like the guide tube has been revised (no part no. suffix?) but it looks like the bearing has been (01E141165D rev D?)
perhaps made looser or out of some slippery or softer material?

when hot, the sleeve expands and the tolerances get tighter and binds, and it gets hot by spinning on the input shaft, a lot of friction

[ArthurPE]

top pic
note same bearing (item 4) is used on the VW synchro, but the guide sleeve (item 9) is bolted to the tranny like the BMW's

there is a weep hole in the bottom of the tranny...I wonder if thoroughly cleaning the components with some brake cleaner while working the clutch would abate the problem (at least for a while)?