so the other night i had my vette out and a friend ask to drive it. i went along with them they drove it way more normal then i was expecting but were complaining it was hard to shift. never grinding or seeming out of order. they were short so i assumed they werent pressing the pedal in enough. i get in the car to go home and it won't hardly go into any gear at all. shifts fine when the engine is off. so i replaced the clutch master cylinder and the slave cylinder. no difference. i recheck everything. dont know what to do other then drop the trans out and look at the fork. about 5 years ago i loc-tite'd the pivot ball into the bell housing cause it backed out on me. it made a mess of shavings and you could hear the fork rubbing the pressure plate when you pressed in the clutch.. none of this is going on. i am going to try to bleed the slave one more time as i didn't have a helper after a while. i tried putting a spacer between the slave and the fork. no difference. clutch has 4000 miles on it and the trans has about 2000. anyone have this problem?

I would make damned sure the system is bled right. I would rather not think of bad things, ya know?

This all just instantly started happening. No signs of it. I've had to change the master and slave before. And dealt with the clutch issues. This is a new tranny. I've not really had a chance to beat on it. It's not been really race. And it's engine is not out if this world powerful. I am clueless as to what else it could possibly be.

I am a bit curious, too. I mean, it shifts with the engine off, so I am more thinking clutch/hydraulics vs transmission.

Either way, I am not excited at the prospect of taking it all apart.

No gear at all, eh? Have you tried starting it in gear? I know, sounds really stupid dangerous, but if you put it into, say, 4th, try to start it with good forward clearance, you might get the info you are looking for... it's not perfect, but it would confirm a clutch related failure. I would consider disconnecting the opti, so it won't start. Just crank and see if it moves the car at all.

how does the pedal feel? is it soft or what? if it's soft, it makes me wonder if something has failed...

It will go in gear but it creeps as you are trying to jam it in. It WILL go in. But it's not easy and every gear is equally difficult. Engine off its as it normally is. You can start it in gear. The car moves unless you are on the brakes. Once under way it is like shifting without the clutch. I did what I had to do to get it to where I could work on it but it was not liking it. Nor was I. The pedal feels normal. It felt normal before I swapped everything out.

Your slave master cylinder is full? It does seem similar to low fluid or air in the system. Is there low pedal pressure?

The pedal is fine. I filled the slave before I installed it.

Quote:

This tells me the clutch is not fully disengaging...
Will

That's where I'm at. But why.

bent fork? bad pressure plate? random anvils falling from the sky? God hates you?

My luck all of the above.

If the peddle is good and the slave is getting full travel, then the fork is bent or the TOB has a cracked collar where the fork pulls on it.

Recently had a TOB collar crack on a ZF6 and it was a deal where it gradually got worse and worse as the crack migrated around.
Will

I can't find a throw out bearing anywhere. Are they the same as a camaro?

no... Corvette only, AFAIK...

Call Carolina Clutch. They sold me a TOB when I needed one.

I hope you can get it fixed..... Really sorry to hear about your problems... I know pulling the ZF tranny is a dream come true.....
Will

Especially since I just install a new one in the car 6 months ago. The tranny that is.

I feel your pain. I am having the exact same issue with my 90' C4 ZF. It just started too. I noticed a mildly progressive issue with getting in into gear but it went. Now it doesn't want to go into gear if the car is running. However, it goes into gear just fine if the car is turned off. My clutch is only a year old too:

Let me know if you find out more about this please: sean_maxwell @ c o m c a s t . n e t

I'm going to try and bleed the system out. If that's not it I'm going to have to drop the trans and find out what the hell is happening. I will have some news for you soon. And pics if its more then air in the system. But it feels normal. So who knows.

Thanks buddy.. look forward to hearing from you.

Sean - welcome, love the handle! Very clever.

Check the system hydraulics before claiming clutch death.

Another option is a hydraulic throw out bearing...

The problem? These parts are now being made in China... cheap shit junk made of stamped steel and spot welded.

Prozac - check NAPA, they may have the bearing.

I've topped off my DOT3 fluid so far but I'm more of the IT nerd variety. I know some gear heads so maybe they can help me diagnose the hydraulics system. Thanks for the input bogus.

I partially diagnosed my issue. I saw the clutch fluid reservoir was empty and added some fluid. After pumping the clutch pedal about 10-20 times, the gears are now shifting much better. I might have had air in the lines but not sure. I'll be keeping a close eye out for leaks. Hope this helps any readers out there. By the way, for those who don't know, the clutch fluid reservoir is similar to the brake ones, but it is located down by the battery beneath the ECM(?) hookups on the driver's side. This is accurate at least for my 1990 C4 ZF 6-speed.

They are all the same.

Glad you found the problem.

the hydraulics in these things have been problematic over the years. Back about 5 years ago, GM had a run on slaves with the seal installed backwards, causing huge leaks!

A real mess... no question...

Glad a little fluid helped it out!

What kinda IT do you do? I am a systems analyst.

Unfortunately for me bleeding it did nothing. I'm going to pull the trans this weekend and see wtf is going on.

I hope it's an easy fix...

Yeah, so far so good. Hopefully the other guy's issue isn't too bad. I started with help desk stuff but now I am doing circuit repairs to mainboards, printers, servers, etc.

wow. I didn't know anyone still did that level of service on boards. Impressive.

If the throwout bearing is bent or partly failed, it will cause the fork to have extra play in it, and go in further than normal before hitting the t/o bearing.

Problem is I don't remember how much is normal. I do remember on mine that I have to force the slave into it a bit to get the nuts started on the bellhousing studs. So check that and see if the slave installs easier than you rememeber 6 months ago.