GlenL

Reading but not seeing: is the intermediate shaft new or near-perfect and lubed right?

tammons

Powerglide it

Really, all this is exactly the reason I sold my car and bought an 83s auto.

My last car the following happened twice. The capture ring that holds the TO bearing in place on the PP ground down into the groove where it fits.
It is square in section. What I took out was triangle shaped. the the bottom of the groove was pushed in and sloped. Never found out why it was doing that. Everything else looked fine.

Last time I rebuilt it i had the same problem as you. Could never get the IP to work properly.
That combined with clutch hydraulics that are impossible to work on and my decision was made.
I even bought one 81 928 that the PO had converted it to an auto because of constant clutch problems.

An S4 clutch make sense if you are having mysterious clutch problems. Gees what else can you do. Everything is new. The only thing I could think is somehow either the input shaft is causing the problem, or you just got a bad IP. How is your input bearing ??

I spoke to a friend no too long ago, and explained that i felt that entire 928 clutch was an after thought. Working from the back forward, and from the engine back, opps, we have to work something out here.

i am sure it was not quite like that, but it is a real disaster IMO.
Who in the heck made the decision to use a pull clutch over a push clutch %^**

The problem I was having was the entire clutch force is transfered to the surface of a small circlip and that was forced with some spinning down into the works. That would not happen with a push clutch.

hacker-pschorr

I really need to get Jim logged on so he can explain what is going on – I’m sure I’m missing some details here.

The intermediate plate has less than 2,000 miles on it. Since it was installed in 2004 – the clutch has worked perfect, every time. Pulled it out of storage this year, life is good until a few weeks ago when I started to notice it was not disengaging when cold. Only took about ¼ mile of driving to clear up, so I didn’t really worry about it.

First we have to assume you believe that Jim knows what he is doing when adjusting these. Let’s remove the human factor here for a moment. This is the guy who installed an early LSD into an S4 trannie (that many say is close to impossible and not cost effective, well, he did it anyway). He also converted his S4 to an early clutch, never had any issues with it.

He is seeing with his own eyes, while the clutch is being used, the T-Pin adjusters shifting forward, all the way forward, and staying there. The result is the front disk being trapped between the intermediate plate and the flywheel. This has nothing to do with the shaft since the intermediate plate has zero contact with the shaft.

What the hell maybe install the intermediate plate backwards?


Ok, back to Plan A:

I have:
Complete S4 clutch kit (bearings, disk, pressure plate etc…)
S4 flywheel

I do not have:
S4 clutch fork

Once I buy an S4 clutch fork, is there anything else I will need to install an S4 clutch into my 81? How about the bell housing? Will the S4 flywheel simply bolt onto the 4.5 engine? How about the clutch shaft? Are those universal? The TT to clutch shaft coupler? I’ve checked over the PET for parts, what the PET will not tell me are the little “gotcha’s” when doing something like this.

AO

Sorry guys - I've only touched a single disk so I guess I meant to say do it on the friction plactes. Dennis (SueDen), here in Michigan, did this on his '82 Weissach and he said that before he did it the clutch would not stay aligned. After, everything is buttery smooth and stays aligned. He picked this tip up from the 928 mech (who actually owned a 928) at the local p-car dealership.

GlenL

Hacker,

Having the discs not move on the shaft is one of the insidious problems in getting the clutch to work right. I've also seen some speculation in that the intermediate plate will self-adjust a bit. This is why the "crack-em-back" method works.

That the IP moves forward can cause the problem. What I'm wondering is if it's clamping the disc to the flywheel or it's the disc not floating back enough.

As to Plan A, can't help with BTDT. I suggest checking the starter P/Ns, though.

hacker-pschorr

Thanks Glen - I'm looking over the PET - just wanted to find someone who maybe has done this swap to find anything part numbers will not tell you.

Back to your theory - if the disk is not floating back enough, that would mean it is stuck on the flywheel, correct? This will cause the clutch to stay engaged.

Or are you saying the rear disk is not moving back with the pressure plate? Even if this is happening, how would that cause the T-Adjusters to shift forward? They would simply stay in their "adjusted" location. This is not happening, they are sliding forward. Jim did try the "crank'em back" method. They all shifted all the way forward.

Jim bailey - 928 International

You will need an S-4 5 speed upper bell housing. As far as what is wrong with the double disc clutch ? I would suspect that the central clutch shaft is worn and there are notches on the splines where the first disc by the flywheel rides that would keep the disc close to the flywheel. The intermediate plate is designed to self adjust but ONLY toward the flywheel (this compensates for disc wear) so when the disc hangs up perhaps the intermediates plate THINKS that the disc is worn and automatically adjusts down toward the flywheel. I had had several customers fix this type of problem by installing a new central clutch shaft after changing everything else. We have also thrown away a number of used central clutch shafts because of such wear. Also note this condition usually happens when new discs pressure plate have been installed the discs are now thicker and disc hub should be riding in a new location but sometimes drops forward into the old wear groove.

hacker-pschorr

Jim,
I fully understand what you are saying - I see how this can happen. 2004 when this was happening, we did try a known good (out of a different car) shaft, problem did not go away. New intermediate disk made the problem stop. The disks were not changed.

Due to the complexity of this clutch, I'm willing to try anything. I'll give your idea another shot.

Care to put your money (ok, Marks) where your mouth is?

Send me a known good shaft - I'll pay for overnight delivery. If that does not fix the problem, I'll pay to ship it back - no cost on the part.

If it does work, well obviousally I'll buy it and owe you guys lunch the next time in in LA. Whadya-say?


A friend of mine has an S4 torn apart (engine out) he is willing to "loan" me everything I need to make the S4 clutch swap work, then I'll buy him a replacement part. Are the starters the same?

So far I need a clutch fork and a bellhousing from him. So far so good, this is an excellent backup plan if the shaft Jim is going to send me does not work

AO

Deal? or No Deal?

drnick

mmmm.... i wonder if this is like the probs my mechanic was having getting the clutch to ajust after the auto-manual conversion... i will have to check and see if the intermediate shaft we are using is new or used.

hacker-pschorr

Anyone have a picture of Monty Hall?

Is Mark there yet? It is early out in SoCal - box it up before he even notices

New or used - just send one you know is good.

AO

GlenL

"What Jim said."

Sometimes I gotta work...

BC

I think you need to start with a NEW central shaft. Not a used one. And it needs to be lubed up REALLy good with the proper lube.

Secondly, because of your SC, I do not think you should "revert" to an S4 clutch, with the heavier flywheel, etc.

As Jim Said, the bell housings are different - doesn't that sound fun Hacker? Changing the freaking bell housing when you are not sure everything will work?

Keep it simple and easy first.

*NEW* central shaft - and then you will have one anyway if it doesn't work.

BC

As I recall when I was adjusting the clutch on the 78 before I tore the car down, I adjusted the IP and it worked great for about two days. There is obviously a GROOVE somewhere that the clutch will return to.

Is this the best clutch design ever? **** no. Its horrible, and too complex for its worth. But do we have any options, IP wise? Not that I see.