How to test a broken clutch release fork?

[cab83_750]

Hi Guys,

Without dropping and separating the tranny, is there a quick way to test if my fork is broken?

For reference, the clutch on the '83 SC needed adjustment once every two months. Last week, the omega spring broke so we replaced it along with the cable.

Reinstalled, we made the typical 1.2 gap followed by 1.0 gap after tightening the cable. Then we checked the play and we are at the .98" play. With the engine 'not' running, the shifter will go into gear.

Once we started the engine, the shifting will grind. I opened the cubby hole, made the adjustment there. After many tries, the car will still grind into gear when the engine is at idle.

Based on my search, I have a 'clutch release adjustment' issue and not a 'clutch adjustment issue.' The most likely candidate is then the release fork.

So, any tests I could perform? The only test I can think of is to unhook the omega spring and see if I could move the clutch release lever by hand; is this a valid test? Any other tests people have done?

Or, do I have other issues?

Thanks.

[Rekoob]

im in the same boat as you with my '78sc. i would love to know if there is a test to do, but from what ive seen/heard you pretty well gotta open it to be 100% sure.
glad someone asked it for me. keep us posted on what you come accross

[Ronnie's.930]

Originally Posted by cab83_750

So, any tests I could perform? The only test I can think of is to unhook the omega spring and see if I could move the clutch release lever by hand; is this a valid test? Any other tests people have done?

Or, do I have other issues?

Thanks.

I don't know of any tests (other than eyeballing it), but what you describe will only really tell you something if one of the fork tines is broken completely off (which doesn't usually happen). If one of them is cracked, even much of the way through, I don't think you will get much movement of the shaft by hand. Obviously, it wouldn't hurt to try, however.

[cab83_750]

Originally Posted by Ronnie's.930

I don't know of any tests (other than eyeballing it), but what you describe will only really tell you something if one of the fork tines is broken completely off (which doesn't usually happen). If one of them is cracked, even much of the way through, I don't think you will get much movement of the shaft by hand. Obviously, it wouldn't hurt to try, however.

I was thinking of by "hand with a little bit of a help from a screwdriver".

What is your 'eyeball test'?

[Ronnie's.930]

I meant doing it the hard way - taking the engine and transmission out and separating them. You can see some of the fork assembly though the hole on the bell housing on the 930 transmissions, but I'm not sure it you could see a crack that way (and don't know if the other 911 trans have the same inspection port).

Usually, with a broken or cracked clutch fork, you have lots of pedal movement with zero disengagement of the clutch.

[fanaudical]

For reference, on my '75 with 915, I could get full clutch travel at the arm with a broken release fork. I had to separate engine from tranny before I could see that the release fork was indeed broken. The bottom arm separated from the rest of the release fork. I do think you need to drop the engine to know for certain (unless you can get a borescope into the top inspection hole and coincidentally the top arm is broken off).