jpNcos

Let me first introduce myself, my name is Josh and I am in Colorado Springs, CO. I love cars and enjoy working on them when I have the skills and time. After looking around for a little bit I decided on this 82 knowing it had some issues that needed addressed besides the fact that it had been sitting for a while. Well this was in Feburary and living in Colorado and having a short summer driving season I took it to a local mechanic that came recommended from some of my other porsche owning friends.

I was wanting the timing belt / water pump done as well as the other things you would to to a car that had been sitting for a while. When I purchased the car I knew it had a bad clutch and would not go into gear easily. So the mechanic has had the car for 8 weeks now. The timing belt was changed in the first couple of days and we maybe lost a couple of days waiting on parts. "Thanks 928 International for all the effort so far" Anyway we have thrown every part at it that is involved in the clutch. Including trying a couple of other tricks.

Anyway this is where I need HELP. The cluth is supposed to have a movement of around 17mm minimum and we are only getting 14mm of travel witch will not allow it to disengage. We even tried a 944 master cylinder on the hopes that it had a longer travel. So what is next? I need to mention that I can manually get it to move proper disatnce with a pry bar but not pushing on the pedal.

Any and all help is appreciated and if there is any other 928 owners in the area, I say hello to you and hope after my car is running we can get together for a mountain criuse.

Again I am new to this car and forum but have tried searching for a prior post that may address this issue. Thanks again I love this car black on black full leather and that body nothing sexier in my opinion so I hope I can bring it back from the brink.

shmark

Sounds like air between the master and slave. These things are notoriously difficult to bleed, BTDT. First thing to try is bleeding the master because it doesn't require replacing anything. Then use Stan's procedure to remove the whole thing if that doesn't work, but it does mean replacing the blue hose. Here's my old thread on it. Both writeups are in the thread.

Clutch Master/Slave replacement

Otherwise could be a problem with the master or slave cylinder, but I'd bet on air in the lines first. That will prevent the full travel.

nosnow

There is suppose to be a plastic cup where the release arm mounts to the upper bell housing. Take the air cleaner off and you should be able to see the top of the arm where the ball socket is. Many times the plastic cup degrades and falls apart. That may account for your loss of travel.

Verify the system is bled properly as it is an uter pain in the rear to bleed. I found the reverse bleeding method to work very well. Basically take a locking needle nose pliers and grab the slave cylinder throw out rod pushing it back into the slave cylinder several times. This apparently does a reverse bleed, I found it on rennlist someplace but can't remember where.

On my car the throw out bearing housing bent causing the clutch to not disengage.... This is a common issue so you may need to drop the clutch pack to see if that is the problem.

jpNcos

Thanks for the quick info. I am hoping that it is being bleed properly as it has been bleed at least 7-8 times. The clutch has been in and out at least 9 times. The plastic cup was replaced The master and slave also have been replaced. I ordered the "blue hose" but comparing it to what I had on the car my guess is that it was repalced within the last couple of years and maybe a 100 miles ago. I think this is why the car was parked. It looked like the clutch has been played with recently by the PO bolts were all shiny when I got it.

Please keep the advice coming as I will be spending my weekend trying to figure this out. These Colorado summers are to short for down time and I want to get this thing drivin the twisties

shmark

If you can fully disengage the clutch with a prybar and the ball cup is good and the pedal adjustment is good, then there's air in the lines. You should be able to push the pedal and watch the slave pushrod move through the full travel. BTW pedal adjustment, make sure the power spring is doing its job by fully pushing the pedal back. When the pedal is fully out, the pushrod should be adjusted to be 10mm clear of the master piston. So a slight pedal travel before touching the piston is correct, about 1 turn of the rod end. One additional thing, it's a dual-disc clutch and might require adjustment. Hard to explain but the procedure is here somewhere, and could exaggerate the issue, but it won't affect the pushrod travel problem you're seeing.

Landseer

The two clutch disks are different and directional in terms of installation. Pictures are posted throughout this section of the board, if not what you need, I have others stored in the computer we can pull-up of each piece.

The intermediate plate has adjustment features. I assume you did the t-bar pull-back process.

The actuating mechanisms can have wear, such that the slider sleeve doesn't provide enough motion.

But you are saying the slave isn't moving 17mm (should be at least that much as you say, per wsm).

The best thing you can do, if you haven't, is block out 2 or 3 hours and search / read on this exact subject here. Its been covered, probably you will find the answer. Wish we had pictures of your clutch install parts. Its also possible somebody switched-in wrong parts. Some subtle differences over time and model years.

Do you have any pictures of the parts? Thickness measurements of the int. plate, flex plate, discs, etc.

Master innards and slave innards replacement is something I had to do.

It has been reported that the flex line underneath can collapse internally like a brake line and restrict flow.

I know these are half-baked, without seeing more data, pics, its hard to help from here.

robot808

Josh,
I've been experiencing some clutch hydraulic issues recently. I have found the write-ups in the DIY section of this site very useful.
Good luck,

Mrmerlin

good advice I think Mark meant the freeplay at the push rod for the master is about 1mm not 10mm. Before you go any further i would suggest that you verify that you have the correct master and slave also confirm that the throw out bearing and the release arm are also the correct parts. There are also early and late slave pushrods, so you might want to check to see if the slave is close to fully compressed when its fitted otherwise it may be reaching the end of its travel. The trick to adjusting the intermediate plate is in the WSM, basically you want to meausre how much distance is between the fingers so to have the same amount on either side you would do this with a feeler gauge and then by turning the engine to measure all 3 of the fingers

jpNcos

Keep it coming this all sounds like good advice so far. the master and slave are all brand new as of 2 weeks ago from 928 Intl. so I would assume these are good and correct. I will have to double check on the throw out brearing and the release arm as car as at the shop 30 min away at the moment (no lift at home YET!!) The intermediate plate was also replaced (Thanks again 928 Intl.) and adjustment has been no problem and have tried playing with it several different ways to no avail. Clutch kit at the same time also.

I have actually put in about 20 hours just reading through everyones posts on various clutch issues there seems to be many but darn it I love going through the gear box on these mountain drives.

For argument sake I think and hope it has been bleed properly but will give it another go in the morning using the procedures in the posts. Also I really don't think the problem is with the intermediate plate is the issue either but nothing seems to be working so I give it another go. Anything I might be missing no matter how simple you might think it is. I'm starting to go cross eyed on this problem so fresh prespective is apprciated.

Sorry no pictures at this time I'll see what I can do this weekend if it really would be helpful.

Is there anything I can do to increase the pressure to make the travel stronger possible getting the extra travel I need?

jpNcos

Just double checked and YES the throw out bearing and the release arm are brand new.
Pretty sure I have tried all the little tricks that are out there regarding bleeding. I have to think that there is something else that I am missing. Please dig deep someone out there has surely dealt with this nightmare.
Thanks again so far this is an awsome group of very nice people here.

Landseer

Well, as 928 Intl is involved, you are getting top-shelf parts and advice, Jim's probably walked you through all the potential issues?? Did you guys do a part-by-part number review or photos at all? Mr Merlin is pointing out parts changes with time.

Is it disengaging at all, ie, one plate only, partial slippage, or not at all?

Central shaft spline condition ( must allow sliding of splined clutch plates)....

Wrong flywheel, so thick it can't allow disengagement?

Clutch central shaft is entering the pilot bearing ok, ie, in the right position, leaving distance between torque tube end and central shaft end --- and then the coupler fits right in this and only this position.

Trying here.

jpNcos

It does disengage at time in fact I thought I had it one time. I drove it around for about 30-45 min. and it seemed to be all good. Let it sit that night and when I got in it the next morning it was slightly worse then by time I got it half way down the street I was limping back in 2nd gear the whole way. The flywheel is about the only thing that is night brand new so I guess that could be a possibility. Spline seems good everything moves fine manually just not with the pedal. I can get it to shift great if move everything manually. I have looked through the manual and the pedal assembly seems good also and honestly feels like a good clutch pedal feel. If that makes any sense to anyone out there. And yes 928 Intl. has been great in many ways. Thanks for the ideas Chris

jpNcos

Does anyone have the link that talks about the different slave pushrod early and late? Is this where I'm losing 3mm and how can I tell?

I've been following manual procedures on the intermediate plate.

All the parts are correct after looking this morning.

Flywheel measures correct .

Thanks again for all the help I know I can get this thing yet.

Charley B

If the nature of the problem changes, that means it is almost certain to be a hydraulic problem.

Mechanical items will generally give a consistent response to input.

Clutch cylinder systems have some really diabolical ways of retaining air pockets.

Landseer

I saw that mm / slave actuator reference someplace here and will try to help you find it. Maybe its part of a discussion where somebody was retrofitting the twin-disc clutch set-up to an S4 or later car and trying to choose parts.

Could be you have a combo mech/hydraulic set of problems, but that's some good logic in the post just above!

My recent install went similarly to yours, still not quite happy with it, but replacing and rebleeding, then driving it, have helped.

Was real hot yesterday, and seemed that the disengagement was on the edge again. Read the "clutch in Scott's racer" thread and surmise I STILL have air entrapped. Diabolical does fit as a descriptor. JADZ 928 lent me a bleeder to try / gotta do today. I messed-up my back and am dragging a bit lately, gotta get it done.

So, hang in, you will solve, others are right on the edge with you, too.