Clutch fork broken

[ssfrancis]

This weekend my clutch pedal hit the floor. the little arm on the throwout is now a half inch in a different place than it was before. Cable and pedals look good. So I'm pretty sure its the fork.

Car: 74 Carrera- 3.6-> 915/44

I just did a clutch job and did not replace the fork because upon inspection it looked great (that was a mistake). My questions are mainly around what to order to get her back (and keep her) on the road:

Is there a chance it damaged the Pressure Plate? I did try to re adjust the cable/Arm but the pedal was very stiff.... I'm worried that trying may have bent the PP

I have a centerforce PP. Is there any reason to suspect the extra pressure caused the failure?

Is there a better clutch fork out there? Our host has a OEM and a Porsche brand.... is the Porsche one worth it? I cant believe how often these seem to break.

This is the 3rd engine drop in 3 weeks on this car... I'm getting really good at it though!

[moneymanager]

Are you really sure it was the fork?
If the little round pin holding the clutch to the cluster shaft shears you will have exactly the same symptoms, including sometimes partial (incomplete) clutch action. Pull the cluster and check this before you drop the engine; could save you a few hours and dollars. In normal operation forks should last for 20 years or more; mine have. OEM means Porsche uses the fork. If you need one, it should be fine.

[ssfrancis]

Thanks for the reply.

The cluster seems to be moving freely and properly with the cable disconnected.

the real sign for me was the movement of the arm on the bottom of the tranny. At rest is sits about 0.5in more forward than before. I can't see how that would happen with our internal damage to the throwout mechanism... but I'm so open of other ideas than dropping the engine again!

I'll double check.

[Bob Kontak]

Hmmmmmm - stiff pedal? The omega spring may have broken. (assuming you have one)

You said it went to the floor. That hints of no tension but then you say you have stiff tension.

If you can still shift but with effort, hone in on the spring.

[moneymanager]

You may well be correct. But the cluster pin is always suspect in my view. My last one sheared but continued to work except it would slip a bit every month or so, causing the clutch to come out of adjustment. So I'd adjust it again at the rear, drive for another month, and it happened again. Pedal never did go to the floor. I lived like this for about 2000 miles! No one could believe the pin was a problem.
I dropped the engine figuring that the fork was slowly giving up and needed replacement. It was in perfect condition. Only pulling the cluster and driving the pin out revealed the culprit. The pin came out in four pieces!

[ssfrancis]

I guess I should have been more clear. After the pedal hit the floor I had no pedal.

The omega spring reversed due to the little arm moving. I took the C-clip off, re positioned the little arm on the clutch shaft so that I could readjust the cable. After that stiff pedal and no clutch release.
I can feel that the top of the clutch fort is in the TO bearing but cant get any info on the bottom of the fork.

I'm pretty sure its the fork or something internal.

Sounds like the OEM fork is fine to go with. Any thoughts on PP damage?

I have to tow the car to my garage space and work from there which is a couple hours away. Thats why I need to know what parts to anticipate... otherwise its another long trip.

[ssfrancis]

I think I may change the pin just for piece of mind!
Thanks for the suggestion

[Howard M]

Same symptoms. It was my cluster pin.

[ssfrancis]

Forgive me, but how does the cluster pin explain the movement (resting position) of the actuating arm on the transmission? (Small arm on the splined part of the shaft)
It moved far enough to be well out of range of the adjuster bolt.

Dont get me wrong, I would love it if this was the solution!

[AVIMAX]

I had this problem, changed the clutch fork this past weekend, one of the arms cracked (see photo) and it was still engaged with the throw out bearing. However, my pedal didn't go bang, it slowly deteriorated over the course of an afternoon. At first the clutch action felt a little soft, then it started to get harder to push the clutch pedal, then I couldn't disengage the clutch completely, then the pedal went 1/2 way to the floor. By the time I made it home the pedal was almost all the way to the floor and I could't change gears. At least I made it home.

FYI, that part (clutch fork) is not in stock with Pelican, they quoted 3 weeks to order it from Germany. Luckily, I was able to source is locally here in Toronto.

[ssfrancis]

I'm getting the feeling thats what mine looks like
Did you have any damage to you PP from the uneven pressure?

Originally Posted by AVIMAX

I had this problem, changed the clutch fork this past weekend, one of the arms cracked (see photo) and it was still engaged with the throw out bearing. However, my pedal didn't go bang, it slowly deteriorated over the course of an afternoon. At first the clutch action felt a little soft, then it started to get harder to push the clutch pedal, then I couldn't disengage the clutch completely, then the pedal went 1/2 way to the floor. By the time I made it home the pedal was almost all the way to the floor and I could't change gears. At least I made it home.

FYI, that part (clutch fork) is not in stock with Pelican, they quoted 3 weeks to order it from Germany. Luckily, I was able to source is locally here in Toronto.

[tobluforu]

Can you remove the starter and get a mirror in there to take a look?

[AVIMAX]

No damage to any other parts. All I needed was a new fork, 3 rubber seals and a new roll pin. Back on the road today and the clutch feels great. Good luck!

[moneymanager]

Removing a starter is almost as hard as pulling the whole motor, at least for me!
I'm skeptical that you could see anything even with a mirror if you did pull it; the fork points away from the access port you'd be looking through. A boroscope might work if you had one. Anyone done this?

[ssfrancis]

Well... turns out the fork is fine but the pilot bearing pulled from the pressure plate. From the look of it someone put the toothed washer on the wrong side of the PP.
I can believe I didnt notice when I changed the disk.

[moneymanager]

We need to add this to the list of all the things that might have broken when the clutch goes to the floor!

[tobluforu]

Originally Posted by ssfrancis

Well... turns out the fork is fine but the pilot bearing pulled from the pressure plate. From the look of it someone put the toothed washer on the wrong side of the PP.
I can believe I didnt notice when I changed the disk.

Same thing happened to me, but I didn't mention it cause I thought mine was so rare.

[mreid]

Let's be clear on terms. The pilot bearing is attached to the flywheel. Based on your description, it sounds like the throw out bearing pulled out of the pressure plate. That usually happens when an incompetent mechanic doesn't realize you need a press to install the throw out bearing and just jams the locking ring into place without the spring washer. I'm surprised it lasted as long as it did. Not sure I'd add this to any list other than what not to do.

[ssfrancis]

Originally Posted by mreid

Let's be clear on terms. The pilot bearing is attached to the flywheel. Based on your description, it sounds like the throw out bearing pulled out of the pressure plate. That usually happens when an incompetent mechanic doesn't realize you need a press to install the throw out bearing and just jams the locking ring into place without the spring washer. I'm surprised it lasted as long as it did. Not sure I'd add this to any list other than what not to do.

Very good catch. I meant throwout bearing.

[mreid]

At any rate, glad you found it! If it's the original fork, you might want to change that while you're in there.