wildwestsydney

Hi all, I have successfully driven my megasquirted fuel only 84 euro for 2000 plus miles. I am still tweeking and tuning but I have no problem getting into the throttle, I feel I have a pretty good tune. Checking the plugs indicates the motor is running nicely.

The question; my clutch is not operating as I think it should. The symtoms; I let the clutch out slowly and the clutch starts to grab with a small amount of pedel movement I would say less than a 1/4 of the total pedal movement, the grab can only be described as heavy drag. It takes half of the rest of pedel travel to get the car to actually move. It is a bit difficult to drivel due to the fact that you feel the clutch start to engage and you add throttle but you don't go forward and the rpms just climb. I would like some advice, comments, experience with how this clutch should work.

I have read through the clutch threads but could not find anything that I am describing.

1984 euro 5spd

thanks

sam

GlenL

The hydraulic clutch system should feel tight and sure. Engagement span of like 1 inch of pedal travel, or maybe less.

It sounds like you've got air in the system. Check for threads on bleeding the dual-disc clutch.

Imo000

Do a search on dual cluch disk adjustment. Sounds like yours need a bit of tweaking.

GlenL

Right.

Between getting it bled well and getting the intermediate plate adjusted it is a challenge to make it work well. You'll find a variety of ways to bleed the air out and long, vigorous discussions of how to adjust the intermediate plate. That all should give enough to think about and try.

Once set up correctly, it works great.

SharkSkin

It sounds like one plate is grabbing much earlier than the other. Most likely you have too large of a gap at the three adjusting forks around the perimeter of the clutch pack. I wrote up a "Theory of operation" page to explain how it all works together, and there is a link to Dan Perez's video showing it in action. Note that you might have to hit "reload" after all of the images load to end up at the right section, depending on which browser you are using.

mark kibort

actually, Ive never liked the feel of the 928 clutch. it need full pedal engagment and full pedal release.
Since dave and I totally agree on intermediate plate adjustment now , I think he would also agree that is not a factor in this description of the charateristics. However, clutch blead will give a firmer pedal if it feels soft or is slow to react. BUT, there is also a balance spring on the top of the clutch pedal that adjusts counter spring pressure. (it can pull the pedal up faster and more completely).

From all the 928s ive driven, you describe exactly how a 928 clutch feels and reacts.

mk

WallyP

None of the ones that I have driven feel like Sam's does...

Sounds like either a maladjusted center plate or wear in the center shaft causing one of the plates to hang up a bit. It is also possible that the lining is loose on one of the friction disks.

GlenL

In the name of all things good and decent in the world, please don't start that.

A worn intermediate shaft is a good possibility.

In order of difficulty:
1) Bleed it (look for procedures)
2) Adjust the Ts on the intermediate plate
3) Drop the clutch and inspect for bad parts.

SharkSkin

I don't agree -- I think that there may be a number of things going on here, lots of good suggestions above. I will not respond here except to answer further questions by the OP... if you want to discuss the whys and wherefores with me you can find my email address at the top of my home page.

To Sam -- don't discount any of the advice given here. Wally makes a good point, it could be an issue with the lining; however unlikely it should be checked. My new clutch engages over a much smaller range of pedal travel than what you describe. None of us are "there" so we are all guessing based on your description.

I would add to Glen's list, check the release arm ball cup. You can reach it with the car on the ground by removing the air filter housing. Prod it gently in various directions with a prybar - you should only get minimal movement and no real play.

It's normal to feel the clutch sort of engage in stages. First you feel some light drag, then a bit later it begins to bite. From your description there is too much pedal movement between "drag" and "bite".

wildwestsydney

I did some investigating under the car today, I pulled the bell housing cover and used the pry bar to watch the clutch work. I got side tracked by having to helicoil a couple of the cover threads, the bolts were broken by a previous owner or their mechanic and left with no attemped to fix. I made an adjustment to the H's. It is raining pretty good here and I am going out with the girl for her birthday tonight so I will forgo a test drive until tomorow. I will deffinately look into the bushing, that is too easy.

thanks all for the advice.

Sam

mark kibort

It is hard to describe, but what I have seen, or felt, is most 928s engage almost at the bottom and dont fully engage until the top. intermediate plate adjustment usually only effects the fully "clutch pushed in" function. the most likely issue, if here is one, is the disc surfaces, pressure plate pressure, and clutch activation system. (i.e. master, slave, lines, etc). In comparing the 928 clutch to the BMW clutch systems, the engagement and feel is night and day in my opinion, and Ive driven quite a few of both.

mk

GlenL

And the 928s, and 944s, that I've driven have a short range of action and feel very tight and solid. But now I'm repeating myself, too.

mark kibort

Let me repeat myself and ask a question. if you are WOT in 3rd gear and you just press on the clutch slightly, do you get clutch slip? can you get the car into gear with the pedal not near the floor? does it start grabing from a standing start a soon as you start releasing the clutch. If yes, thats what I see am saying. in a BMW, for example, i feel it is MUCH more easier to drive due to a narrow engagement and release characteristic. anyone, no matter what the skill level, is very awkward in my cars with the clutch. the 928 is different in that area, in my opinon,

Now, ive raced and or driven on the street for more than an hour or so:

andersons
Fans
Devek's 6.4 liter beast
Scots
Randy's GTS (almost new in everyway)
Aarons 85 (almost new feeling)
my 84
Brians 87
Gregories 6.0 Liter 88
my '79
Chucks euro 928 racer
and the Holbert car.

All of these cars seem to share the same feel. It just seems that the activation of the 928 clutch is a little longer than most cars Ive driven, besides a 928. Hey, my opinion through experience, thats all.

mk

Imo000

Mark,

Are you saying that even the sinlel disk cutches feel the same as the twins?

mark kibort

Actually, the single disc seemed to be a little different, and had less chatter upon release. It just didnt have the clamping force, but that could have been due to its age. (holbert original) Now, Randy's GTS was a little different. infact, it felt very stiff, and had good clamping force. I was amazed as it had near 420+rwt. I was speaking mainly of the twins Ive driven and adjusted.