Can someone walk me thru clutch adjust issues? (there's pictures!)

[Hotwatermusic]

Here's what's been done: New clutch cable, clevis and pin, well sorted pedal cluster with bronze bushings, fresh Kendall gear oil. As a control, with the engine off and clutch untouched, I could easily put the shifter in 1st, 2nd, and reverse. 3rd was tricky, and 4th and 5th impossible. After adjusting both ends as per Bentley manual, the clutch cable looks like this at rest:


There didn't seem to be enough engagement with the standard adjustments. 1st and 2nd made the horrible grinding noise, and reverse was impossible to get into (just grinded too, as if I hadn't waited long enough). Also the clutch pedal wouldn't return to its normal resting spot, it just sort of hung back about 2 inches behind the brake pedal. So I adjusted the cable at the transmission end for more pull, which ended with the cable being drawn to the end of its range, seen here:


This gave me better engagement, I can get into 1st and 2nd gear with no problem now. Problem now is the clutch pedal still won't return to a normal resting position. I had a helper come work the clutch while I watched underneath the car. Here's what I saw, first at full pull:

But when they let off the clutch it wouldn't return to its normal resting spot, and looked like this underneath the car:

The omega spring is about a 1 cm away from the heat exchanger.
I then had the helper use their foot to pull the clutch pedal back even with the brake pedal and with a "THUNK" it banged back against the heat exchanger where it belongs.
This can't be right, right? What am I missing? Any help would be much appreciated, this whole thing has had my car out of commission for more than a month and I so ready to get it back on the road.

[pete3799]

74 with an 83SC is probably part of the problem.
What year is the trans?
A quick search of Pelican doesn't show an omega spring for a 74.
Also lists a clutch cable w/ threaded end not a hook end as you show on yours.
And your missing the return spring on your small release arm.

[schumicat]

in addition to the missing spring (it goes where the notch in the small arm is), your trans also seems to have two sets of ears through which the cable passes - one where the clutch adjustment threads are, and another that is squishing the rubber boot. On my car (and on the photos in the 101 projects book) there is instead a very wide opening where you have the boot squished. That may be part of the problem.

[Porsche84]

I see a big gap between the adjusting screw and the pulled arm (might be the photo). This should be a very small gap. I adjust mine so there is about 0.5 mm. Very strange setup with two slots for the cable adjuster. Is there an adapter to use the later version cable? You are missing a spring on the shorter arm as someone else pointed out.

[Hotwatermusic]

The car shifted and drove fine with this exact set-up for the last 2 1/2 years, and I assume many years before that with the PO's. The 83 engine and trans has been in the car for a really long time. The clutch cable I took off the car looks exactly like the one I replaced it with.

Now this return spring on the small release arm, can anyone share a link to this part in the pelican catalog?

[Hotwatermusic]

Originally Posted by Porsche84

I see a big gap between the adjusting screw and the pulled arm (might be the photo). This should be a very small gap. I adjust mine so there is about 0.5 mm. Very strange setup with two slots for the cable adjuster. Is there an adapter to use the later version cable? You are missing a spring on the shorter arm as someone else pointed out.

No, there is little--if any--gap between the adjusting screw and the pulled arm. Bentley says 1mm, but in my trying to adjust everything to work, that gap ended up being a business card basically.

[RWebb]

did you check the cable arm itself at the pedal cluster?

that arm often cracks and/or distorts

[DRACO A5OG]

Well, this is for the 3.2 but may work on your hybrid:

Before you adjust anthing, remove, clean and lube the shaft of the helper arm and clutch arm shaft that comes out of the trans. All this adjustment and a binding clutch is very frustrating. Ask me how I know.

I will just focus on your question of adjusting the clutch:

A helper would really be asdvised to press the clutch pedal as you take your readings and make final adjustments.

I assume you have the car jack uped already and safely with jacks and chock.

OK, with the cluth pedal untouched, get your first reading. It is measured from where the cable disappears into the end loop to the the tip of the adjustment barrel. Note that reading.

Ask your helper to press the clutch and take the reading again from the same points.

Now do the math. the difference must be 25.0 MM (+/- .5MM). That's it.

Like you said if she ran perfectly couple of years ago. Why worry about it, Enjoy your Baby

BTW, one thing I have to mention is it appears from your pic the cable looks like it is maxed out i.e. Stretched. If you can not get any further then where you are at in the above pic, you may need a new cable or see if you can get a shorter one. My 2 cents. The cable has to work triple duty with it's current set up from what I can tell.

[pete3799]

spring is part #915-116-614-02-M260
Pelican Parts - Product Information: 915-116-614-02-M260
Your trans. doesn't have a stud to hook the end of the spring to.

[rusnak]

The cable installation is totally messed up.

See above pic for correct installation. The large arm must be pryed rearwards after installation, before adjustment. I can post detailed instructions later.

That adjustment bolt gap is way too big. It needs to be 1.0 mm after removing .2 mm of cable slack. The lock nut on the adjuster must be tight.

[DRACO A5OG]

Oh yeah, while driving, you want the clutch to engage in the middle of the travel of the pedal. The pedal should be all the way up at rest with the 25.0 MM l

[Hotwatermusic]

Originally Posted by rusnak

The cable installation is totally messed up.

See above pic for correct installation. The large arm must be pryed rearwards after installation, before adjustment. I can post detailed instructions later.

That adjustment bolt gap is way too big. It needs to be 1.0 mm after removing .2 mm of cable slack. The lock nut on the adjuster must be tight.

A couple people have brought up that they see a large gap between the adjustment bolt and the small arm. There is little-to-no gap between the two. It only looks that way in those pictures. Here is a picture with flash:


I simply can't figure this one out. The car was owned at one time by someone from a well known Porsche shop here in Austin, and when I bought it it was very well sorted. Everything worked perfectly and it shifted like as well as could be expected from a 915 trans 911.

Is it possible I kept the old clutch cable on too long, continued to use it in a stretched state to the point where other parts of the clutch/transmission were brought out of spec? And even though I changed out the clutch cable, pedal cluster, clevis/pin, and made all the proper adjustments, the damage has occurred further down the line that I can't see?

Why wouldn't the strength of the clutch arms be able to bring the omega spring, and subsequently the clutch pedal, back to the proper resting position?

[RWebb]

you are not too far from Ed Mayo's shop...

[Hotwatermusic]

Originally Posted by DRACO A5OG

Well, this is for the 3.2 but may work on your hybrid:

Before you adjust anthing, remove, clean and lube the shaft of the helper arm and clutch arm shaft that comes out of the trans. All this adjustment and a binding clutch is very frustrating. Ask me how I know.

BTW, one thing I have to mention is it appears from your pic the cable looks like it is maxed out i.e. Stretched. If you can not get any further then where you are at in the above pic, you may need a new cable or see if you can get a shorter one. My 2 cents. The cable has to work triple duty with it's current set up from what I can tell.

That cable is brand new. Hasn't even seen the road yet. I had to max it out, otherwise the clutch pedal felt like a loose tooth, it just dangled on the cluster. When I bought the new cable I compared it to the old cable on the floor of my garage, and except for the rotted boot of the old one, they were identical in every way. I will do the removing and cleaning of the helper arm and clutch arm as you suggested. I'll have to get out the Bentley manual for those though, never tackled that job before!

[Hotwatermusic]

Originally Posted by RWebb

you are not too far from Ed Mayo's shop...

I can't get to Ed Mayo's shop. I can't get to ANY shop!



Who is Ed Mayo? What's his shop called? Is it here in Austin or somewhere in central Texas?

[rusnak]

I can't figure out why that omega spring is so far from the heat exchanger. The large arm is not in the right position. Loosen the cable adjustment nut and pry the big arm all the way back. Place a brick under the clutch pedal to keep it in position.

The cable ought to be close. If it's way short, and the pedal is heavy, then the cable is hung up on something in the tunnel. The adjustment bolt should be around 1.2 mm gap. Tighten the cable until the gap is 1.0mm.

[rusnak]

That 1.0 mm gap is really important to not wear out the to bearing and clutch disc.

[rusnak]

I think the cable is too short. Loosen the cable, anf pry the big arm rearward, and re-adjust. I think that will do it Don't forget to put a brick under the pedal to hold it in the up position.

[DRACO A5OG]

Originally Posted by Hotwatermusic

That cable is brand new. Hasn't even seen the road yet. I had to max it out, otherwise the clutch pedal felt like a loose tooth, it just dangled on the cluster. When I bought the new cable I compared it to the old cable on the floor of my garage, and except for the rotted boot of the old one, they were identical in every way. I will do the removing and cleaning of the helper arm and clutch arm as you suggested. I'll have to get out the Bentley manual for those though, never tackled that job before!

Hmm, maybe you can tighten the cable up at the pedal, it really needs to be shorter so you can adjust it in the future, of just buy new one evertime, like you did.

More importantly is the 25.0MM differntial of pressed vs unpressed.

The clean and lube is easy the way your set up is, there is no spring on the small clutch arm and the omega ring seems to be non-functional.

Simply remove the circlip and the small arm will drop, just note the orientation, then there should be a dust cover then the larger Helper arm then another dust boot. You may have a roll pin on your set up, look for that, it needs to be popped out so the arm/s will release from the shaft.

It should just slip out, just unhook the cable loop. If it does not slip off, then there is some rust, tap it out. Good reason to clean and lube.

When you ready put everything back in reverse order.

But in your case set the adjustment screw pictured above to 1.5MM then attach the cable loop. It should reduce to 1.0MM after setting the cable adjuster to difference of 25.0MM. Example: unpressed the reading would be 75MM, when depressed 50MM = 25.0MM. This is just an example your reading should be different.

Unless you are planning to install a stub for the Omega Spring, you do not need it.

Damn your clutch must be heavy as heck

If your other cable is the same length you could have kept it but like I mentioned try to shorten on the pedal and you will not have to replace it the next time around for adjustments.

Jim

[RWebb]

another approach is to run it like a '74 trans. is set up - you do have a '74 trans, right? or did I miss something

Ed Mayo is in Fawt Wowth & has been around a long time