Five-8

Hi All

I'll try to keep this brief, although trying to sort out the clutch trouble is becoming a bit of an epic.

The Symptoms: Grinding into reverse, intermittent grinding into 1st...intermittent vibration with clutch pedal fully depressed, shifting that i would describe as "notchy", requires a VERY firm hand to downshift into 2nd, no issues when cold.

So far...new intermediate plate, new pressure plate, used but low mileage discs and release bearing, new master cylinder, new slave cylinder with the 2 hoses(new)...have adjusted the intermediate ring according to Deveks "principle" (all the way back)...new cup...bled and re-bled the system complete with the "funky" good stuff from Roger.

when the clutch was dropped ...my mechanic inspected the shaft and found nothing amiss (marking/grooving) but by his own admission said it was only a cursory inspection...this is all that is left to replace.

have yet to increase the length of the rod on the clutch pedal (as was suggested by "dogleg"? in a previous post...

clutch behaviour is exactly as it was before any work was done.

i love my 928 to bits, and i love my mechanic(no...not in that way)even tho he isnt a Porsche guy, ...i knew going in there was likely to be some frustration before i bought the car...i get that...but this is starting to wear on me(and my wallet)

I appreciate all the help on this issue those of you whom have offered up suggestions, clearly there is more to be done...just asking for some more suggestions...based on the things we have done...we know what Isnt the cause of the trouble...need to keep going to find what is.

Cheers,

Adrian

Mike Simard

It might help to revisit the adjustment tabs. They can be funny about working or not and multiple trips under the car could be needed.

This just has to all be related to the discs dragging

blown 87

Sounds like the new master cylinder was not modified.

Dave928S

Has to be one or the other.

Adjustment of the intermediate plate has to be just right or a plate will drag. What do you mean by "all the way back" as far as the adjustment you've already done?

LT Texan

Have you visited SharkSkin's website? He has a good writeup on dual disk adjustment and theory. (Round 30)

And you can see my AWESOME youtube video of my 928 clutch in action. (Pats himself on the back.)

blown 87

No, trust me on this, it can be both.

Lizard928

You are all off.....

The key is in this statement....

You're adjustment of the int plate needs to be changed.
push the tabs all the way forward. Then use a ratchet strap to pull back the release arm (other end on rear crossmember). Then move each tab back a tiny bit slowly going around. As you do this you will find a spot where the front disc gets JUST enough room to spin freely. Stop at that point. You will know when you have hit it as the engine will be rotated manually, and the discs will no longer be spinning. Once you have done this you will have no more issues.

If this doesnt work, or you cannot figure it out mail your old (if surface is good) intermediate plate to me and I will fix it in the correct orientation so that the problem will be gone permanently.

soontobered84

Ding Ding Ding Ding. I think we may have a winner

I replaced a master cylinder on my '84 and became a master bleeder having bled the damn thing until there was a shortage of brake fluid in US. Nothing helped. Finally saw the thread on the differences between master cylinders. Made the mods and it worked great.

hp18racer

I ruled out a problem with hydraulics on my car by having my son work the pedal while I measured travel of the slave cylinder rod. Spec for travel is in the Factory Service Manual. Lets you know for sure where to focus your attention.

hacker-pschorr

Read Colin's post again, if he's adjusting the intermediate disc "all the way back" that needs to be fixed first.

blown 87

Wont matter how it is adjusted, it is not going to work right if he has a new style master cylinder in there that has not been modified.

Lizard928

Actually, I have had the new masters work without problems when the clutch is adjusted properly.
It really reduces the required throw.

hacker-pschorr

It's a 50/50 chance the master is the problem and we know for a fact the intermediate disc is adjusted wrong. Might as well start with what we know.

Same here.

Glenn Evans

Has your pilot bearing been replaced? It's the one in the rear of the crankshaft, into which the spigot on the front of the clutch driveshaft fits. It sounds to me as though it could have excessive wear and is allowing the driveshaft to drop when the clutch is disengaged. Should it fail completely, the ring gear will contact the clutch housing.

Before you fit a new one, prise off the shields, clean and repack the bearing, then replace the shields. I did not follow this advice first time around, and the new bearing from Porsche lasted only four years. The grease in the next new one seemed to be aerated and needed changing, That bearing has been fine for seven years.

Podguy

Glenn,

How do you pack a sealed bearing? Do you put grease behind the bearing? If so what prevents from spraying out and getting on the clutch?