911

Hill climb Stiv3, 1995 RA transmission and a nice new AP Organic on a stock flywheel.
Problem: With very hard competition driving, the clutch pedal will stay down about 50mm from the 'top' position. the clutch is fully engaged, clutch changes are sharp, but no slip at all using it this way.
Drive smoothly on the road, and the pedal is perfect!
Any ideas as I realy do not have the time to pull the box out as I'm racing next weekend.
You can pop the pedal up to the fully 'up' position with the gentlest of pull-up using the tip of your toe! Sometimes the pedal will pop up by itself....
It only happens when I drive the car very hard as if the thrust/pull bearing is sticking on the gearbox input shaft housing, or the clutch spring in the cover is sticking or binding?

Driving me mad, any good ideads guys?
It never did this with the old original STi clutch/box.
911

Denmark

iTrader: (2)

Itīs the slavecylinder thatīs the problem,take it off,remove the rubber,take out the piston,an the back of the piston there is a small spring,strech it a bit ,put it back on and bleed the clutch and of you go with a new feeling of the clutch


Skassa

Pavlo

excellent, this is the exact same problem as mine. I have posted a few times and the only suggestions are the extra tension spring to the fork.

Many thanks

Paul

Denmark

iTrader: (2)

It was someone on here(canīt remember)(sorry) that gave me this info,and itīs working great


Skassa

911

Skassa, you are a gem!
Will try this before the race this weekend. You can't believe how off-putting this is when you are approaching that tree lined bend a touch too fast.....and second gear might get you out of trouble.
When I push the fork against the slave piston rod, so pushing the rod into the slave, it is very lazy to extend back to meet the forks location recess. Adding extra springs to the fork's existing one Pavlo won't help I think. The mechanism is a bit strange, but this is the first 'pull' clutch I've ever come across. That spring only seems to serve to take the slack out of all the connections.
Thanks, and any further suggestions will be very interesting!
911

Pavlo

that extra spring is to stop the acceleration of the turbo cars preventing proper release of the clutch.

Paul

scunnered

iTrader: (1)

I had the same problem for a while. I tried the spring thing but it didn't work. So I had a look at the pedal. There is an adjustable rod coming from the pedal. A couple of turns on the adjuster cured it for me.

BART!

I cured this problem by removing the spring under the pedal ! This spring returns the pedal to upright position but also works as a helper spring .....The first inches of travel the spring pushes, but after a certain point the spring pulls the pedal down ....

Removing this spring makes the pedal feel more lineair, however downside is that pedal 'floats' a bit in top position and pedal is a bit harder....but as I said...it cured my 'pedal to the floor' problem...

911

Bloody great guys, Snet to the rescue again thank god!
I've sketched out the mechanism 'train' of the scooby clutch, and with htis the fact that all I did is change the clutch parts over, so why would I have this now? Must be the geometry of the AP cover spring (?). Is something going over centre, ie Bart!s point. PLUS, it only does it when I am accellerating very hard, if I cruise things are perfect!
When I race the car, I do actuate the clutch pedal very hard and quickly, hence the problem shows itself.
I wonder if I have fully engaged the thrust bearing retaining spring clip when I re assembled the clutch/box???

Things like this really pi*s me off, it is a lot of work to pull the box just to fix this, and I race for championship points this weekend!

Please keep the ideas/experiences coming!!
911

911

Scunnered, did you lengthen the rod or shorten it? I wonder if the pedal travel is just too far for the AP clutch cover? ie, fully depressed pedal moves the fork too far and pulls the cover spring just a bit too much911

Shropshire-Guy

Aint got a clue on this 911. Sorry mt8. Lots of Answers but its never happened to me yet, so aint got a clue mt8

911

Advised last night that to increase the spring rate on the existing clutch arm will fix a similar problem.
Seems I have several things I can do external to the clutch/box removal, so logical to try this first.
This has all left doubts in my mind now when I fitted the clutch. IF I have left the spring clip off the thrust bearing which secures it to the clutch cover, would the system have failed by now? That is, the bearing will have pulled out of the cover? Surely this is so otherwise the clip would be pointless!
Bloody cars!
911

ukbob

the spring clip is attached properly otherwise the clutch would not work."pull type clutch".!

911

Bloody hell!
Still have the problem!
Checked the lot except for the hydraulics. The springs, adjusting free play lubrication etc did nothing.
This leaves the slave cylinder tweek. TMIC comes off yet again!
There is a lot (seems to me) free play of the thrust bearing sliding in the clutch cover diaphram spring, about 6mm. This is with the spring off so you can push/pull the clutch arm easily. Is this correct? I would have thought that there should only be about 1mm or even less play? Any play there will be amplified at the clutch slave cylinder end of the arm about 4:1.
Everything worked perfectly before I changed the clutch, but I kept the Sti thrust. Very tempted to run as it is for the next 2 races and pull it all out. might even put my STi cover back on as only the plate was on it's last legs, hence the change.
Is a Subaru Sti clutch as good as an AP organic???
Realy frustrating now!
911

Tim-H

I have the exact same problem on the virtual exact same car,(95 sti RA, ap organic on standard fly) I have tried ajusting the helper spring on the pedal but this only moves the problem and results in cluch slip if you go to far, I have recently had a new ap cluch fitted by a very good motorsport specialist (Graham Quick) Who I spoke to before hand about the problem, they also found a very badly worn thrust bearing, which looked as it may have been sticking on the shaft, the problem went away for a while (fitted xmas done about 4000 m) but is now showing more in the dry weather :-) again.
The piston spring seems a maybe ?
I will speak to Graham shortly,he hadn`t heard of it on rally cars, and maybe go for a cylinder change as it could be just wear in the "normal places" and when you pedal on a bit they are the bits not so used. how many miles has yours done?, mines on 70 thou.
as you say it does bug :-)
I will mail you if I get any luck,
Tim

911

For those who have followed this issue; I have cracked it!
After stripping the box/clutch out i did the following:
1 Replaced the MISSING dowl location pin , one of 2 on the box/engine face.
2 Fitted a new thrust bearing to the release arm prior to re fitting the box
3 Stretched the clutch slave cylinder internal spring to 60mm long (about a 50% extention.) Bled the clutch.

It now drive as it should. I cannot get the pedal to stay at mid point no matter what I rev to etc.
What a game!
911

AlanG

Glad it's sorted 911.