915 Clutch positioning lever, broken spring attachment
 

1983 ROW 911sc 915 trans
Hey guys, I just discovered my clutch positioning lever had its spring attachment broken off a long time ago… guessing 20 years. So it hasn’t moved and is locked to the clutch release lever.

So:
How do the positioning lever and the release lever act independently if they are splined to the same shaft. I can’t tell from drawings.

Is there an another way to position clutch cable? I’ve got it close to where it was before I had the great idea to adjust it.

At this point I think it’s go by feel? Should I make it a little in the loose side and tighten to engage? Better to slip and not engage then to crunch

Also what about fixing.
Is the trans housing where the spring peg used to live solid and perfectly suitable to tap and install a new attachmentment site? Alternative spring attachment sites.

Regarding loosing positioning lever. Is it better to pry against the shoulder of the clutch release leaver or socket and hammer on positioning lever to break the bond

Post a pic of what you're talking about.

Are you referring to the omega spring ?

http://forums.pelicanparts.com/uploa...1749949941.jpg

1983 911sc ROW
Sorry, I forgot to add details and IOS picture upload interface has never worked with my patience. Not omega the little adjustment arm. 1.2mm cable disconnected, 1mm with cable tensioned. I just tried to put another picture in with some arrows ect but uploads are usually unsuccessful for me unless I’m using my laptop

The short arm is splined, the long one is free wheeling when it isn't seized on the shaft due to rust. The short arm can live without the return spring unless you decide to fab a stud of some sort to replace the broken off spring tit on the trans rib.

The short arm moves the fork. The long works with the omega spring assist for more leverage.
Prior versions of the clutch setup are simpler, a cable attached to one arm, and they still work fine. I believe that short lever is positioned at the right place in your pic. That omega looks like it is already in "released" position.

Some have used a puller.

A block of wood and a BFM might work too. I wouldn't pry ... unless you want more chunks of that AL case taken out when the tool slips.

Thanks for education. So the long arm must be the stuck one.

The reason for asking is I started to do the adjustment according to Bentley ONLY to release the two levers were stuck and the spring isn’t there, so I lost my place of what was working pretty well as it was perfectly fine before I starting trying to make it “right”

If I do manage to get it to easily loosen will NOT having the spring affect the 1.2. And 1mm reference values?

Are there other ways to determine if I’m in a good spot to start trying to fine by driving? Should I start looser on purpose and then tighten to reduce risk to tranny

Take a pic of the omega spring area.

I want to confirm my suspicion it is already released.

Keep in mind all that 1.2/1mm stuff is for the OEM setup.

Nearly spilled my drinkhttp://forums.pelicanparts.com/uploa...1749961141.jpg

OK, it isn't released.

The missing spring doesn't affect those reference values because the 1.2/1mm adjustment relates to the long arm and the clutch cable as long as the short arm is in the right position which is the case.

I believe factory adjustment should be fine then.

Thanks for the quick help ya’ll

Is The aluminum case is solid here to tap and attach a new post… 4-5mm bolt 10mm in or so
http://forums.pelicanparts.com/uploa...1750016244.jpg

And to clarify what I think your telling me
The spring acts when the clutch pedal is released to soften the return of the fork to itss out of way position

You will have to make that call for yourself ;)

The spring is in tension so it certainly helps reduce effort to disengage the clutch.

I reread your original statement that the short arm "hasn't moved and is locked to the clutch release lever." for the past decades and am wondering what was the gap between the levers before you adjusted them.

O
There was no gap, which as I understand now would mean I didn’t have the one inch of pedal travel before engaging the positioning lever

I left it with a tiny space .25 mm as I’m hoping for miracles and it will break loose now that has some room to move independantly

Regarding tapping the transmission case… do you have any idea or inclinations, I’m not sure what the nod and wink should mean. I can’t see why it wouldn’t be solid. The only reason to not is that it really isn’t that helpful once you dial in the sweet spot

Intriguing.

To me, zero gap means you have a "backdated" setup, perhaps something they did "back in the day", which evidently has been working for the past two decades. The fact that the long arm is contacting the short effectively makes them operate as one unit.

For that reason, I would go back to the zero gap since it also acts as a stop in lieu of the missing spring.

Sorry .... I'll put it this way ... it means I probably won't tap into my AL case but someone braver than me might and I don't mind seeing them try.

However, I don't see a reason, other than going back to the factory setup, why you need to reinstall the spring when the current simpler setup has been working.

I do have a followup question, what does your clutch pedal look like engaged and released ?

I think this was “backdated” because of a ham fisted mechanic or maybe it’s the best solution with the loss of the spring

I’d love to go back to where it was… except I changed the values for the stopper bolt AND. The cable before I realized the big lever was seized to the shaft

As to why I started mucking with it in first Place, I didn’t really like the pedal feel and wanted to change the engagement/ release point which I believe should be modified at the pedal cluster, but I was going “by the book” and was starting at the trans before moving to the pedal…
I’ll put up a pic later

Any records on the car ?
This forum goes back only 25 years so any prior practice is based on privately passed on knowledge most of which is gone I suppose except in the cases when a car such as yours show up.

If the cable has been replaced, then I agree to restore the OEM setup.

Personal preference is a good reason.
You might prefer the non-linear feel of all the additional springs and levers.

PMAX
I went to take a picture last night and it was more time investment then I had and I my free time was gonna be spent making sure I got it close enough so I could shift again. I nailed it or at least for first and reverse. Don’t have time for a road test yet.
BUT I’m still annoyed by how low the engagement point is… 2/3- 3/4 to the floor so I will get to the pedals soon and post a pic back soon and I’d love your impressions before I adjust

I’ve got records back two owners. I know when the clutch was done and there’s no mention of the issue. The previous owner to me did the clutch cable and just let it situation stand since it had worked fine for 20k miles
I put in 3k last year and it was fine, I just don’t like the engagement point so low

Drill and tapp the case and place a nut and bolt in the broken nub location.

More help please…
Can I adjust the location of the pedal travel? I had been under the impression that I would adjust pedal travel at the cluster independently from the cable position, but after reading up the adjustment at the pedal cluster WILL AFFECT the cable length

Do I have this correct, and if so which direction (tighter/looser) at the stop adjustment will raise engagement point off the floor. I assume if I’m taking more cable up into the cabin I will need to loosen the cable at the transmission to maintain 25mm.

Also if there is a good read on this part of the adjusted that’d be great. Wayne’s doesn’t mention and Bentley is one sentence and the internet keeps sending me adjustment at the trans

Thanks. 3/16 diameter 1/2” deep seem about right? . That rib looks pretty solid. I assume it’s where I’d place the jack if I was dropping the transmission.

Good to know !
The factory setup based on the omega does raise the pedal but introduces a dead space at the beginning of the movement and makes the action non-linear. I don't know why Porsche added it in the first place when the drivetrain ethos is about being smooth and direct.
Again, if that's your personal preference, that's a perfectly good reason.

The clutch cable is under tension so lengthening the travel at one end will shorten the other.

I bit the bullet and tackled tonight. First compared attachment at clutch pedal… looks like it was OVERTHREAded at the pedal. 17-22mm of thread installed. I compared to Joe engineer post picture showing 17-22mm depth

So I hoped all at the pedal was second order and went back to trans. Two full rotations at the transmission and I can hear the spring at the fork moving 2.5” in, I could be missing silent movements in clutch but it’s good enough for tonight. I’d estimate engagement movement moved 3”+ up from floor

Surprisingly I think the assist spring on the pedal assembly contributes more to that non-linear feel. Without that in place the clutch feels significantly more linear, but it becomes quite a chore to hold the pedal down.

Edit: And it's the assist spring on the pedal that actually lifts the pedal and introduces the dead space at the start (which you can of course adjust). Without the assist spring the pedal doesn't go all the way up and can flop around in that dead space.

I was thinking bigger, but 1/4” would work. Always coarse thread in soft metals or plastics.

Make eure the surface is flat and perpendicular to the hole so a washer and locking nut sit properly.

If you lived near I would say bring it by my shop.

I agree the springs contribute to the non-linear feel.

The 1mm gap in the OEM setup when the clutch pedal moves but the fork doesn't is dead space, in fact literally.

Adding the springs on top of that further decouples the forces felt at the pedal from the movement.

The earlier setup dispenses with most of this complexity and I suspect is preferred in a non-street setup.

Still strikes me as odd that pin would shear off just like that by itself, the spring isn't that strong.

Taking a closer look at your pic, what is that circled in green ?

http://forums.pelicanparts.com/uploa...1750277110.jpg

@ PMAX
I’m sure something was ran over and brokeThe nib off. It certainly wasn’t the spring breaking the nib. Some rock somewhere, or some dip**** ‘mechanic misplaced his jack and “CRACK”
Your green circle is just a trick of light, there’s no crack or flaking going on there.

Here’s some other photos from the pedal cluster. I took it out for 30 minute drive and by the last 10 minutes I was back to shifting at 4K confidently. A few more drives before I’m confident. I do feel its engagement is raised off the floor slightly from before, but I could be hallucinating. I’m not sure you can actually change the position, or if it’s just shortening the amount of travel before engagement.

Sounds like you're back in business.

Congrats.

Thanks Pmax

Been working hard under the car in spare minutes and no time for posting. Had my car to my mechanic for inspection. He used his patented air hammer vibration and the big arm got loosed up finally after 1/2-3/4hr of coaxing. Glad it was him. It would have taken me 10 hrs if I didn’t break something first.

We set it and it was good. Then I got neurotic and went hog wild and set the proper 17-22mm at the pedal, reset at the trans. My new spring arrived and went through the heart wrenching how do I tackle spring…

I went as minimal as possible… I drilled a 3/32 through the housing and slipped the spring in. It is the least invasive and strongest way, while it doesn’t look factory, a broken nib isn’t factory either and tapping and setting a screw in factory location is still possible, though I see no reason.
Height feels great and I’m rolling with 0.8mm for dead space and love it. It’s very tight!http://forums.pelicanparts.com/uploa...1750565597.jpg