christiandk

I have searched through many many adjustment threads, but cant find the writeup for adjusting the early twin disc clutch when the clutch pack is out of the car?

i know I have seen it, but just cant find it again. Anyone?

davek9

you can not make an adjustment w/ it out of the car, all you can do is examine the parts and make sure the "H" levers are not worn out, clean and move freely (some put dry lube on them), also lube the short shaft (see write-ups)

For me the best way is to install the assembly and with the clutch disengaged(that's the hard part) rotate the entire pack and center the intermediate plate. After that it should find it's happy place and self center w/o drag.

If it drags re-due above.

GlenL

There's politics, there's religion and then there's dual-disc clutch adjustment.

My suggestion for the adjusters is to crank them all the way to the rear. That is, with the clutch pack laying with the front disc on the ground, lift the "H" (aka "T") adjusters all the way up and evenly on both sides. Uncomplicated and it has always worked for me.

christiandk

Great thanks,

Do you also lube the PP fingers where the race of the TO touches?

christiandk

EDIT: I am installing new discs so I guess that the adjusters have to be all the way inn to allow for adjustment when the discs wear?

GlenL

Get a manual for the lubrication. It calls for different lubes in different places. Get the right stuff for the intermediate shaft.

Use a screwdriver to lift the adjuster. That'll be done by sticking it in and twisting. This will make sense when you're at the pack.

hacker-pschorr

Sorry Glen, I know we've been around and around with this.... I've tried this method on a number of intermediate discs and it has never worked once, they all dragged. Each time I used my modified bell-housing to watch what the clutch was doing. Not once did the clutch "self adjust". The H-adjusters stayed right where they were, all the way back which caused the clutch to drag.
Maybe this works on a worn intermediate disc? I don't know.

There is a way to adjust the intermediate disc on the bench prior to install. The reason why this usually doesn't work is the adjustment is almost always "bumped" during installation. IMO this is why these clutches developed such a bad reputation. The WSM method to adjust the clutch almost never works and Porsche never had a plan "B" cooked up.

If they had simply designed the lower bell housing with an access panel, they probably would have continued to use the double discs through the production run of the 928.


So.....that's what I have, a lower bell-housing with a hole in it.
https://rennlist.com/forums/928-foru...ch-owners.html

GlenL

Eric, I was thinking about you and your exploits when I was putting together a rebuilt clutch last month. I'm laying under the car with the cargo strap cranked super tight on the throw-out arm and trying to figure out if the clutch was open...or even moving. I had done as I described above, and decided to just button it up and go with it.

The clutch had newly-lined discs that measured 0.8mm thicker than stock, a new pressure plate. and a looks-like-new intermediate plate. With the car jacked up, I fired up the car and could see, to my amazement, that the stub axle stopped turning when, with the car in gear, I pushed in the clutch. On the street it's working great, too.

So... How to set it on the bench? Crank 'em back and if it doesn't work that easy-access lower bellhousing can always come off.

hacker-pschorr

Funny thing is, I've never had the clutch out of my 79, never even taken off the lower bellhousing.....and this is my track car. I know for a fact this clutch has never seen the light of day since the early 90's.

When they are working, this is an excellent design. If I ever buy an 86.5+ with a 5-speed I'll probably convert it.

It's been so long I don't remember where I saw that. Friend of mine has some supplement manual I thought for the transmission that shows a tech bench adjusting the clutch. I tried it a couple of times.....maybe that's why it isn't in the WSM.

Frankly the lack of an adjustment window might possibly be the biggest fail in the design of the 928. Such a stupid simple solution would have alleviated so many issues and saved a lot of synchros.


Looking back, when I had to remove a Rennlisters clutch at Road America to fix the ball in the upper bellhousing, no adjustments were made to anything. I took the pack out, set it aside, fixed the ball, put the clutch pack back in and it worked. Talk about blind luck....

Wisconsin Joe

Well, then I got super lucky too.

I had my clutch out this winter to replace the pilot bearing. And the release arm ball cup.
It turned out that everything else was practically brand new (friction discs, TOB & housing, short shaft, I think even the PP and Intermediate plate too).

Took everything out, cleaned it up, was very careful to not disturb the adjusters, put it all back.

When I fired it up, I could hear the TT spinning with the clutch engaged (pedal up). Push the pedal down, and the TT stopped like it always did.

mark kibort

you cant get more anecdotal then this. there is a reason for the adjustment. the entire PROBLEM that most all folks will have, is that they are too far open. this means that when you push in the clutch pedal, the intermediate plate to gently ride on the pressure plate, which keeps the clutch pack spinning..... No no no. adjust it to 1mm (manual calls for .75mm) but anthing close to that is fine. its only purpose is to allow the front side of the intermediate plate to back off the flywheel.


do not do any lubricating of the H adjusters... as the clutch pack wears, the pressure plate will push extremely hard on the H adjsuters if that much wear has occurred to the clutch pack. it will allow the intermediate plate to press and hold friction to the flywheel. the H adjusters will more than likely never have to self adjust if adjusted correctly in the first place.

mark kibort

I suppose you can find a used flywheel and bolt it all up and adjust the adjusters on the INT plate. BUT, just do it the correct way.. its super easy and is permanent if you do it right and very effective.. Hacker is right, if you push them all the way back and it works, there is something very worn on the system.. again, we fought this problem for many many years with the race cars that would move at high RPM against the springs and friction adjusters. max open WAS the problem and it was very expected there would be a problem. riveting them fixed the issue, but if you have a good int plate and not racing which , can make a weak intermediate H adjusters fail, they will hold and allow for smooth shifting, especially from a stop.

GlenL

If the facts don't match your beliefs than say the facts are wrong. It doesn't get more religious than that!

Mrmerlin

as Mark points out you dont want the H adjusters to be lubricated ,
as they can then move out of the position easier,
thus making the clutch be mis adjusted.

Some have found that pinning the H adjusters when they are set is the final fix,
others, have used small bolts to hold the adjusters in position.

IMHO this is best as they can still be adjusted.
I did make a lower housing with a window for adjustments,
BUT the clutch adjustment was perfect and never changed,
So I never had the opportunity to use the window

hacker-pschorr

My personal theory on this (based on no fact what-so-ever, just a thought) is this works because the "self adjusting" nature of the intermediate disc is Porsche over engineering at its finest.

One of those "ideas" that looks great on the bar napkin but in real world applications is extreme overkill and unnecessary. In the long run has caused more problems than it was worth.