BPS

'94 Z M6, has been parked for a year or so and I am now getting it back on the road.

Started fine but the clutch was very stiff and not smooth, and did not release smoothly, rather it would hang and then jerk up against my foot.

I could pump the clutch with the tranny in neutral or engine off and it would creak in and out but once in gear the clutch pedal would not release. Put into neutral and the pedal would rise. Did this a few times and then things got worse as something started grinding when I tried to depress the clutch when in neutral. So I shut her down.


Figured I'd start with the easiest stuff and replaced the master and slave, with a McLeod Adjustable that I happened to have sitting around in a box. Got that install completed this morning but am having the same problem, Clutch creaks like my knees on a damp morning and does not really want to release once in gear.

However, I did get it in gear and started to drive a few yards. But the release was very creaky and jerky. Almost feels like I need to lube the clutch release bearing so it moves smoothly!

Something is clearly very rusty or broken.

I researched the steps to replace the clutch and they seem a bit daunting (mind you I did replace a cam so this can not be much harder), I could tow it to a shop but rather not get bent over.

I have a street twin siting in my garage (same box the master came from) that I could install, the existing clutch is a Luk 10 yrs old but less than 10k mile on it.


Any ideas before I call a tow or build cribs to lift the car onto...

BPS

Thinking my problem may be a lack of lube in the input collar which is causing the clutch release bearing to bind.

May try to remove the slave and with a longish hose spray a little bit of lube to the top of the fork area to see if it loosens up the sliding of the release bearing.

Now to research the proper lube and ensure that I don't spray too much in there and screw up the clutch.

Chimera96

given you have replaced the hydraulics...I suspect either a bad TO bearing, clutch disc hanging up on the splines of input shaft or bad pilot bearing.

all require the tranny to be pulled to see wtf it is.

at that point I would put in the McLeod Twin. IMHO a very good clutch and what I have.

if you drop the slave, remove the spacer you may be able to see, using a mirror, if the TO bearing top is being pulled off or bent. I have not tried this and there is very little room to see. I don't think spraying any form of lubricant on TO bearing will help.

BPS

Thanks, I'll try to have a look but, like you, I suspect that spraying lube with do nothing as well. Will start building some cribs to raise the car - I figure if I can get the tires up 12-14 inches I should have enough room

Chimera96

I don't have a F-body but did build wood cribs about 6" tall to then put my jackstands on to get the car high enough to drop and pull the tranny from under the car. Need another block of wood on floor jack to get car high enough

I suspect a search or service manual will have a step by step on a f-body tranny drop

I always put a thin coating of high temp grease on the input shaft spline so disc does not hang up on it. very little though so it does not fly off onto clutch disc surface. You can also use graphite spray lubricant. take a wire brush and some solvent to clean the grooves of input spline first

I suspect you have a bad TO bearing but again you won't know until you pull it apart

One quick check is to drop the slave and look at where the fork is. It should be basically centered in the area it sits in. I would send a pic but for some reason this forum does not let me...

if fork is say lower that would suggest the lip of TO bearing has peeled back

maybe the clutch disc itself broke. weird though just sitting for a year should really not effect it other than possible the hydraulics drying out but you swapped that.

BPS

So I removed the trans and am not sure if I found the problem.

See the attached link for pictures pictures

There appears to be some rust in the trans shaft and on the inside of the TO bearing, but not excessively so, as well the TO bearing rotates freely and the pressure plate looks in good shape.

recall that my problem is that the clutch pedal is tough to push in and either does not push back when in gear or does so in a very jerky manner. master and slave have been replaced.

I'm not sure if I gain much digging deeper into the clutch itself - I may try some light sanding and lube or go as far as replacing the TO bearing - although it seems ok.

any thoughts?

Chimera96

that input shaft looks very "dry". It is possible the disc hub spline is hanging on it. Wire brush splines on both input shaft & disc. Put a thin layer of high temp grease on spline. Not to much

since you didn't remove clutch can't see if a hub spring or something broke

you have a real Valeo (OEM) clutch

does the TO bearing turn freely without binding

how does the pilot bearing look?

BPS

Worked on it a bit more today - Figured i may as well swap out the clutch and install the ST i have.

I managed to get the bell housing off today ( got lucky the 10am bolt was loose) - tomorrow I'll take off the PP and fly wheel. I'll need to get the new aluminum flywheel unbalanced as it is balanced and the stocker likely has weights on it.

the existing TO bearing turns freely with no binding, I'll report later on the rest of it.

I agree that it all looks very "dry" with some evidence of rust but nothing so bad that you'd think would lead to the issues I was having. If it wasn't such a PITA I'd just clean and lightly lube the shaft as the clutch, while old, has < 10K miles on it and other than the pedal issue hold well. But as I've gone this far and have the ST I may as well use it.

thanks for your input so far

BPS

Got the clutch out but it all looks fine

i see a mark on the fork fork and PP PP.

I took photos of everything but it all seems OK photos

Guess I'll install the new clutch - I need to order some weights as the fly is balanced - and hope for the best

Chimera96

I would change the pilot bearing. If you intend to keep the clutch I would laso replace TP bearing

You have a ST, just put that in. You do need the weights on the back of the FW so if your Twin did not have them it would be the "neutral" aka "zero" balance for internal balanced motors. That is the one I have as my 383 in internal balance. My FW has the 4 holes taped where the weights screw on to so you should be able to get the weights from McLeod

The ST will have a 13/16 MC so you will need to bleed the hydraulics. ST is a VERY nice clutch.