new clutch wont open

[bcaway]

Likley somethng stupid I did a few months back when I installed a new clutch before upgrading my 74s with a 3.2 and 915 from 1985 carrera.
Just got the DME wired and enging running, however when I tried to back out of garage, cluch depressed but cant get into gear, just grinding. Clutch wont release. I adjusted the new clutch cable to the max, and still nothing. I have the 915 with the large spring coil asist lever.

wife pressed the clutch pedal whilst I watched the short lever on spline which moves about 1/2 inch.

The clutch pedal does feel a little stiff, but I have nothing to compare as the old magnezium 915 had a different clutch and cable.

Is it possible I assembled the throwout bearing wrong?
How much pressure does it take to move the splined shaft that goes into the trans?

I also had a new pressure plate and the flywheel machined with kevlar pads on the clutch, im beginning to wonder if there was a screwup in that and the throwout will never move the pressure plate off the clutch...

though I would ask if its common to assemble the clutch fork/ throwout wrong before I start removing the 915 (ugg)

anyone know if this can be done without removing the engine?

[svandamme]

Originally posted by bcaway


Is it possible I assembled the throwout bearing wrong?

How much pressure does it take to move the splined shaft that goes into the trans?

anyone know if this can be done without removing the engine?

yup

not to much

difficult.

[bcaway]

thanks, looks like im pulling the gearbox out today....

[bcaway]

engine out and gearbox off today.
Discovered the throwout actuator fork was bent (one tag was in the throwout bearing and the other was behind it)

the one behind was binding on the transmission housing when the clutch was depressed preventing any movement.

I removed the fork and replaced it.
This time I double checked the alignment as i stuck teh gearbox on, checking thu the hole at top isnt enough, the botton one cant be seen and I used a mirror and flashlight from from the starter hole.

Everything back in and clutch feels great, took it for a spin at 9:30pm.
So for any newbies like me thats definitly something to catch you out.

[EPorsche]

How bent was your fork. I'm having the same exact problem and we notice the fork was bent at the bottom. You notice the bend but how much is too much? Could a badly adjust clutch cable cause the same thing?

[bcaway]

Mine was at least 6-8mm bent (the bottom one)
I removed it, put in vice heated red hot and straightened.

I also linished (power sanded) the tips so they were all the same.

I doubt the cable adjustment could cause the issue, seems it was done on the assembly, but I bent it by adjusting the cable tight and pushing hard on the pedal.

[EPorsche]

How could you tell the bottom part was not in the throughout bearing? I tried looking with a flashlight and still can't see anything. I do have a fork on order that should be here tuesday.

[bcaway]

when I disassembled it there was a vizzable mark on the belhousing, and the lower fork was obviously behind the thrust bearing. I was unable to tell until I removed the engine and box

When I reassembled, I slid the fork on as I progressed forward with the box, soon as the top fork was in the right place, I stopped and checked the bottom with a flashlight and mirror (thru the hole in the underside) also I wiggled the fork shaft as I watched the top fork and it felt loose and correct. i.e no binding

hope this helps.

[EPorsche]

Thanks, I'll update when the new one comes in and is fitted. Do you have any pictures of a probably adjusted clutch cable?

[EPorsche]

bcaway or anyone (pic),
What side of the bracket does the helper spring pin sit no? Toward the back or the front. I'm looking in the upper right corner. I have it on the back and I think that it's not letting the clutch release. I'm still thinking that it operator error and not the helper spring or fork sense everything worked well before I replaced the clutch kit with the engine rebuild.

[EPorsche]

bump for help

[bcaway]

Here is a good diagram: http://www.pelicanparts.com/911/911_Parts/1978-83/3-1-1.JPG

The adjustment was easy, I followed these instructions:
http://www.pelicanparts.com/techarticles/911_clutch_cable/911_clutch_cable.htm

I'll get a photo of mine and post soon.
Basicly I did this:

1: disconect cable from rear arm.
The arm should be "snapped" toward the rear of the car (I.e the spring is holding it there under tention)

2) adjust the fork arm bold to 1.2 mm (aprox) gap to the spring arm.

3) install cable (hook on spring arm)

4) adjust cable nuts till the gap closes to 1 mm between the fork arm and the spring arm.
(NOTE: 1st time my cable wasnt adjusted enough up front, so I ran outa thread at the read. I removed teh front attachement and unscrewed the adjuster up front. )

Thats it! I had my wife press the pedal while I measured (as in your photo above) and I got exatly 25mm travel.

If the pedal feels hard to push and the floor moves when depressed then you likley did what I did and cocked up the fork install. I take it when the engine is running you depress clutch and try to engage a gear all you get is teeth grinding!

Another thing I noticed while troubleshootign my issue was the gap between the fork arm and spring arm kept changing. (later discovered this is cause I kept bending it more every time I tried using the pedal and forcing it)

[bcaway]

ok 3 images here:
1st 2 are taken from the left (drivers side) facing rear (looking back)


the last image is taken from the right side looking at the left rear wheel.


hope this helps!

good luck
Brian

[EPorsche]

Thanks,
What do you mean by "snapped". I have SSI's like you. I think I understand. The helper spring pin is forward of the blocking bracket (the one with the two little screws). I think you can see it in the first pic. The second shows the helper spring against it.

[bcaway]

yes your photos look correct, the "snaped" back, means if you tried to pull the lever attached to the helper spirng forward it woudl be dificult because of the spring tention, then it woudl go over center adn ping forward.
Your photo shows it pinged back in the correct position.

So once you attach the short arm adn your cable whats the pedal do?

[EPorsche]

I'll find out on Tuesday, but everything should be good to go. Thanks