Clutch Fail - wrong fork?

[mikedsilva]

I posted this elsewhere but figured here is also a good place as someone may have seen it too...

My clutch failed the other night.. the pedal went straight to the floor.... The clutch was still fully engaged and i couldnt disengage.. got the car home and put it up on stands.

Found that the clutch fork would rock back and forth, but not sideways.. At first I thought ball pivot snapped. But turns out not to be.

I removed the transmission from the car and found that the clutch fork had come off one of the pins/spigots of the throwout bearing.. how?

When i cleaned the parts and put it back together to investigate, I can see that the fork only reaches to cover half of the throwout bearing pin.. so while it was working it was ok, but that last clutch depression must have been enough to pry it off.

So the question is, what part is wrong?
The number on the side of my clutch fork is 9011167111R which seems different to other searches that I do for a 914 clutch fork.

Also, googling my part number doesn't seem to bring anything up at all.

Is it possible that I have the wrong fork which is too "short" for my application?

[Dominic]

The 914 parts manual shows the correct part number to be: 901.116.712.00

Looks like you have the wrong release fork.

[Dominic]

Looks like part number: 901.116.711.11 is for an early 911 with the 901 trans... not sure about the 1R part number?

[porschetub]

Originally Posted by Dominic

Looks like part number: 901.116.711.11 is for an early 911 with the 901 trans... not sure about the 1R part number?

Part # appears correct as supplied by OP,this is the fork for the 901 prefix number transmission ,are the guide block pins fully seated into the fork appears not to be the case from the pics ?
The fork for the other 911 prefix boxes won't work in this application so we can count that out.
Is the nylon pivot bush ok?,looks like the clutch has been grinding away @ the fork...not good also.

[mikedsilva]

I borrowed a clutch fork from a friend who has a 914 box in pieces..
Turns out that his clutch fork with the 712 00 part number fits perfectly...


problem solved.. i think.
I will get new plastic guide bushes too...

[TheCabinetmaker]

Would you please post a photo of the two forks side by side to highlight the shape or length differences? I am curious on how they appear different.

thanks.

and I'm glad you found the solution.

what was the wrong fork wearing on? the groove cut in it looks like maybe the clutch was rubbing on it, or maybe some one clearance it for some reason???

[mikedsilva]

The groove happened when the fork came loose and rubbed against the finger springs on the pressure plate...
Here are some photos showing the differences...



old fork


new fork

[Dave at Pelican Parts]

That's pretty amazing--I wasn't aware that there were such differences!

--DD