Paul Workman

I never thought much about where my clutch disengages until I drove another C4 the other day and it was different.

Mine is a '95 and the clutch is fully dissengaged pretty close to the top of the stroke. It has always been "handy" for quick shifts, but now I'm aware that they aren't all the same. (Forgive me, but this is the first hydrolic clutched auto I have experience with). It seems to work OK - no issues w/ it, but now I'm wondering if it is OK or should it be adjusted differently, and if so, how should I go about it?

TIA,

P.

scorp508

The hydraulic clutch in our C4s cannot be adjusted. How many miles do you have on the clutch?

Paul Workman

Ooops! I meant to say too that I have 67000 on it. I bought it 3 years ago w/ 48k on it then, but I don't think the clutch pedal has changed - or perhaps if it has it has been to slow to perceive it.


P.

cresus

I just put a new clutch in mine and it engages very near the top. Someone told me as they wear the friction point lowers on the pedal travel (due to the pull style clutch). I haven't worked it out in my mind but it still seems nice.

bogus

Yea, the clutch on the ZF6 is wierd... and yes, at the top is good, its when it goes to the bottom that things are bad.

And when it goes down, check the hydraulic fluid before you get silly.

music_man

Thanks Bogus - you just saved me some heartburn.... My clutch on my 90 w/47K miles also grabs at the top. I just bought a GTO as daily driver and the clutch on that car is so different. It was making me wonder about if my vette was in for a clutch & a bunch of work for me... Thanks agian !!

k99ja04

Bogus is right, disengaging at the top is fine, when you mash your foot to the floor is bad!

Bogus is gonna love this (and I probably should keep my mouth shut), but I DID machine my dual mass (yeah I know), and after reinstall last year the position of clutch disengagement was much closer to the floor than previously. So yes the tolerances within the bellhousing are pretty tight. Anyone know just how much travel should be in the clutch fork according to spec? I measured mine at 5/16" or so. I didn't have my vernier calipers handy so that is an approximation.

CentralCoaster

Disengaging at the top is good as long as there's no residual pressure on the throwout bearing. The only way that'd be possible is binding, or the reservoir not opening to the hydraulic system.

If there is residual pressure, you'll have less clutch friction, and more likely to slip.

Terry Posten

Since this is about the clutch and where it starts to grab:

My 93 w/93,000 miles is the same way. It starts to engage up top but is fully seated before I run out of travel. Here is my question:

I have noticed recently (don't drive it much, only on good days) that when at a light or drive thru, with the tranny in nuetral and my foot OFF the clutch pedal, I hear a very faint rattling niose. As soon as I put the smallest pressure on the clutch pedal, it goes away.

Is this a sign of a TOB going bad?

I do not know if the clutch has been replaced. I bought it back in 01 and have only put 4000 miles on it.

Thanks.

k99ja04

No, that is either a function of the straight cut gears that make the ZF6 so strong, or your engine / flywheel is out of balance. Annoying yes, but not necessarily detrimental.

Terry Posten

Cool!

I am just **** about my cars being perfect..

Mike_88Z51

Terry, I'm not saying this is your answer, but this happened on my DN 4+3 and it wasn't the flywheel or straight cut gears that make the ZF6 so strong since I don't have a ZF6. Even though these are hydraulic systems with no adjustment on our part, the clutch slave cylinder has an internal spring that preloads the clutch linkage to assure that the TOB is in contact with the presure plate fingers at all times. It could be that the piston seal in the slave cylinder is starting to stick and the internal spring isn't strong enough to compensate. This allows the clutch fork to pivot back just enough to cause the TOB to intermittantly contact the pressure plate fingers instead of staying in full contact at all times as designed. The intermittant contact can cause the rattle or chatter as the TOB "skips" against the pressure plate release fingers.

If you can put the car on a lift or get under it at an oil change place where you can walk under the car while it is running, try pressing on the end of the flutch fork where it meets the slave cylinder rod. (You may need to pull a rubber covering boot to do so.) Push the clutch end fork back and forward where it meets the slave cylinder rod. If the rattleing noise stops, you have found the cause.

yellowlust

Or it's the DM flywheel starting to go bad.