Broken clutch release fork?

[Winter911]

My car is a 1972 911 with the 901 trans.

My clutch engagement felt out of wack since I kept grinding first and reverse.
As I was getting ready to do a clutch adjustment, I noticed the nylon piece has collapsed.
So I unhooked the clutch cable to replace it and I noticed the clutch release fork is completely loose. Is this normal?

Please see video here:

https://youtube.com/shorts/rmdwls0moJ0?feature=share

I wasn’t able to find anything consisting of a loose clutch fork on the forum.. so I’m kind of freaking out now.

I was really hoping to enjoy the car for the fall but I feel like I just hit a wall.

As always I appreciate all your help.



-Martin

[yelcab1]

The 901 has no helper omega spring like the 915 so yes it is perfectly normal for the clutch arm to flop around when it is not connected. If you keep grinding gears while shifting, it is probably because there is not enough clutch travel due to various reasons. Most likely, the parts are just super old.

[ed mayo]

I don't know how 'loose' is the 'loose' you describe, but that is a conglomeration of three generations of clutch operating methods you have there. I'd say replace the broken plastic piece and hope for the best. That appears to be operating as a 'pull' type so there must be some rig for the cable end, and the pivot point of the aluminum 901 box is not in the same place as the pivot point of the correct mag case gear box which used in only 70-71 models.

[Winter911]

Originally Posted by ed mayo

I don't know how 'loose' is the 'loose' you describe, but that is a conglomeration of three generations of clutch operating methods you have there. I'd say replace the broken plastic piece and hope for the best. That appears to be operating as a 'pull' type so there must be some rig for the cable end, and the pivot point of the aluminum 901 box is not in the same place as the pivot point of the correct mag case gear box which used in only 70-71 models.

Ed, that’s really interesting. There’s a nut that has been welded on to the end of the cable, and that nuts slides into a slid on the trans to hold the cable in place.
By loose I mean that the clutch fork is moving freely. (See video)
PO must’ve rigged the clutch cable when he realized he bought the wrong one maybe?

The other problem is that I can’t slide the plastic clevis over the cable because I can’t get the nut off the end of the cable.

Here are more pictures.

[gled49]

U need to start from scratch. New cable #97, the plastic trunion #94,(now available in metal so it won’t break) and the cable anchor #95. It’s normal for release arm to be loose and flop around. And cable guide #92 should be in place.

[john walker's workshop]

Is the loop on the side cover still there and not broken? The cable needs to slide through it and it doesn't look like did from your pictures. That collection of bits on the cable won' t fit through, just the cable itself.

[gled49]

U can see part of the loop on the side cover, but not the top where it wears thru.

[ed mayo]

Is that a mag case with the cable end anchor? At first it looked like a alum. case.

[Winter911]

Originally Posted by john walker's workshop

Is the loop on the side cover still there and not broken? The cable needs to slide through it and it doesn't look like did from your pictures. That collection of bits on the cable won' t fit through, just the cable itself.

It’s still there. You can see it here




My dilemma is how am I gonna install the new plastic clevis (couldn’t find the metal one) without being able to remove the nut at the of the cable.
I would hate to cut it and have to replace the entire cable

[Winter911]

Originally Posted by gled49

U need to start from scratch. New cable #97, the plastic trunion #94,(now available in metal so it won’t break) and the cable anchor #95. It’s normal for release arm to be loose and flop around. And cable guide #92 should be in place.

This is helpful, thank you Gled


Sent from my iPhone using Tapatalk

[Winter911]

Originally Posted by ed mayo

Is that a mag case with the cable end anchor? At first it looked like a alum. case.

Not sure if it’s mag or aluminum. The numbers read 911/01
7119279

[john walker's workshop]

All typ 911 trans cases are mag. The pivot bolt securing the fork to the bellhousing often breaks or unthreads itself and that would allow the fork to move more than normal and not release the clutch. You can look up the fork hole and see if the fork is still attached to the pivot.

[Winter911]

Originally Posted by john walker's workshop

All typ 911 trans cases are mag. The pivot bolt securing the fork to the bellhousing often breaks or unthreads itself and that would allow the fork to move more than normal and not release the clutch. You can look up the fork hole and see if the fork is still attached to the pivot.

It looks like it’s still on the pivot. In which direction does the clutch arm move to disengage the clutch?
Does the clutch arm get pulled towards the transmission or does it get pushed towards the motor?

I think I answered my own question. The nylon clevis piece would indicate that it gets pushed this direction correct?

[gled49]

It also looks like the slot that normally captures the cable end with anchor has opened up and might not hold anymore. Maybe that’s why the nut is welded on the cable end. And that picture shows worn out loop on the side cover. Remember the cable doesn’t operate the clutch arm, the cable housing does.

[Winter911]

Originally Posted by gled49

It also looks like the slot that normally captures the cable end with anchor has opened up and might not hold anymore. Maybe that’s why the nut is welded on the cable end. And that picture shows worn out loop on the side cover. Remember the cable doesn’t operate the clutch arm, the cable housing does.

Yeah that’s what I was thinking as well.
What a mess. A big washer at the end of the nipple would’ve been an easier fix, don’t you think?

I have to cut the nut off regardless to get the clevis out and put the new one in.

[Walt Fricke]

The 911 transmission used the first of the pull clutches (which the 915 continued to use). But how to get a cable to push on a clutch release lever arm which is on the left (driver's) side of everything. Cables are made to pull, not push.

Well, fix the end of the cable aft of the arm, and have the thick Boudin (?sp) tube (part 58), which runs from the firewall through that holder and inside of which the cable runs, be in an arc and not just a straight tube. When you step on the clutch you tension the cable. That straightens the tube/sleeve, making it effectively longer, and, via the intermediate bits, pushes on the release lever.

You can see why this system needs the guide holder John emphasizes to keep the sleeve/tube more or less in place.

It only took Porsche two years to realize this wasn't the best system for a pull TOB/clutch PP, so in '72 we got the 915.