mark kibort

does the pedal now just barely get pressed and move .5" or so before it feels like it is engaging?

if you have too much slack, then you wont get enough movement of the clutch mechanism, and that will act like intermediate plate issues. However, if you are getting the right movement, and have no air in the lines, and it still does it. (not go into gear right) then its int. plate adjustment time.

karl ruiter

Several primary causes:
-Air in the master. It is really a bugger to get every last little bit out. Much worse on the 928 than any other car I have heard of. There is a technique called 'burping' that works very will. Search for it here. I think this is your problem and your solution. Based on the info that it comes and goes and is temperature senstive or something.
-The intermediate plate could be out of adjustment. This has never happened to me, but others report that is has to them.
-The stub shaft that the clutch disks ride on can get worn splines, causing them to not fully disengage. This has happened to me. A new shaft was about $75 last time I got one.
-Grinding can also be a shift linkage issue. There are several areas where there are plastic bushings that can give out.
-Could always be your tranny. But there is good hope that it is not.

Erik N

I don't know what year your car is, but the early ones had a smaller pivot ball for the top of the clutch release arm. On my '78 this ball had sheared off and gave symptoms similar to what you describe. Later cars had a larger-bodied ball with the same diameter head, so Porsche obviously recognized a problem.
The ball threads into the top left of the bellhousing. There is an opening there where the tip of the arm protrudes out and seats on it. If it has broken, you should be able to spot it.

SharkSkin

There is a diagram of the clutch from the WSM near the top of this page. Just below that is a link to a point lower in the page that gives the "theory of operation" with a great video from Dan Perez showing the clutch pack engaging and disengaging. That along with the text should make the operation of the clutch clear.

Check the stuff in the last three posts above. What Mark means above is DISengaging; i.e. the pedal should move very little before the clutch disengages and begins to slip.

My release arm pivot was beat due to a bad combination of old/new release arm/TO bearing, and the clutch worked, just felt funny:





Cure was a used upper bellhousing & a few misc parts.

Let us know what you find after inspecting the above, we'll step you through it.

Erik N

Hey Sharkskin-
I realize those are probably old photos, but you could have salvaged that bellhousing by drilling and tapping out that mess for the larger studded ball.

menzzer37

I'll check the pivot and try burping the master. Clutch adjusting is the last thing I want to do... I think my pan gasket is shot as I'm leaking lots of oil. So WYAIT, I'll do pan gasket, intermediary adjustment, new exhaust, the works. Thanks guys, I'll keep an update after the burp and pivot inspection

Lizard928

Tackle the clutch first.

The oil pan gasket is a completely different game.

Remove the lower bellhousing and adjust the H adjustors.
To do this you will need to turn the engine manually. I use a large flathead screw driver from the starter area and pry on the ring gear to rotate.
I then push all 3 H adjustors all the way in with the clutch stationary. Once all are in I use a screwdriver and pry the intermediate plate backwards until I can see that it will JUST be disengaging the primary plate. I do this to all 3 adjustors and bolt it back together.

Do this procedure first and ignore suggestions by others here to move the H adjustors all the way back and forget about them! That method WILL result in a dragging clutch on all but a few cars!!!!!!!!

Once that is done burp the clutch system to ensure you have no air bubbles.
After this your system will work properly, and as noted zero preload on the clutch rod is needed.

menzzer37

I have the workshop manuals and have been searching, but does anyone have any good pics of the adjustment?

menzzer37

Anyone have a reservoir cap or know where to buy one? mines cracked!

menzzer37

Does the exhaust have to drop to remove the lower bell? Can I leave the slave on?

dprantl

You don't need to remove the exhaust, but you may need an open-ended wrench for some of the bolts since a straight shot at them will be obscured by the exhaust. You must unbolt the slave cylinder before removing the cover. Never press the clutch pedal with the slave cylinder unbolted from the cover.

Dan
'91 928GT S/C 475hp/460lb.ft

sharknoob

Now that you have added the fact that you have a major oil leak... Make sure it is not the rear main seal

Where are you located ?

menzzer37

I'm located in northern Indiana. I just read completely through sharkskin's writeup. I will definately check the main while I'm in there. That bell should be full of oil right? This may also have ruined my disks?

When adjusting the plate, do I have to engage the clutch with a prybar? Does that get tricky when guessing slave travel? Sharkskin said 17mm. Any thoughts?

SharkSkin

The oil will leak out the inspection plug at the bottom. The lower bellhousing can't fill with oil unless someone has sealed that hole. BTW, one of the things you should check before pulling the lower BH is the release arm position. Assuming the pivot ball is OK, that first diagram shows the wear limit, if the arm is at the end of the "A" range of travel the clutch is at the wear limit. Problems with the pivot ball will usually result in this check indicating that there is more wear/life left than what you really have, so check that first. you can get a look at it by pulling the airbox and looking down the back of the engine.

17mm is spec travel for the early cars IIRC, a number of factors can affect that. Newer clutch MC replacements have an internal stop that limits travel. My advice on that is get a helper and measure the actual slave rod travel. Report that measurement back here and the collective experience here can tell you if that's go/no-go/borderline.

menzzer37

Ok, took the air cleaner off and inspected. Cup is good! Someone welded a piece of bar over the rectangular inspection hole though....

I adjusted the pedal a few times and had pretty good success. I think my gear problem is a matter of linkage adjustment. The gearshift is loose while in gear. I think this is the u-joint on the top of the tranny right? I started grinding gears again, so I gave a little more forceful movement of the stick and it bumped right in!