OK, wtf is wrong with my clutch?

[ColinOpseth]

Hey guys,
OK, so my wife's uncle came over and rewelded my clutch bracket to fix the geometry issue. I cut my cluster master pushrod, tapped it and threaded on an adjustable rod end.

When I push on the clutch I am getting at least 1.5" of stroke. I'm supposed to get clutch disengagement at about 15/16". WTF is going on here?

I removed my clutch hydraulics from the car. I tried to move the clutch fork forward toward the engine (I'm using a pull-type clutch so it's reverse of a regular clutch). That sucker won't even budge. WTF? It's like the throwout bearing is frozen or something. Is that even possible? My parts are all-new. Granted, they're a few years old but they have about 3 minutes of run-time on them.

I think I'm going to burn this sucker to the ground. It never ends. This is the last thing I need to do before it's on the road. Anyone have any ideas?

[Len]

Hi Colin
I am a little confused on the pull type hydraulic clutch ? pick would be good .
However you would be hard pressed to manually move the fork and compress the diaphragm by hand,
Almost sounds like you have a hydro problem. Did you have someone press the pedal while you watched for movement at the slave ?
Len

[72 SS PNL]

1 1/2' stroke is about what the gto's have if i remember right

ive never played with the stiupid gm pull clutches , so i cant help much , and yes the t/o can be frozen to the trans , also agree with len , its hard to push/pull against the pressure of the pressure plate with out the mechanical advantage , most are in the 1500-2000lb range stock and go up from there

[Ishiftem]

If I understand correctly(and I doubt it), the clutch will not disengage. With the bearing held against the fingers, the fork should be about 7 degrees to the engine going towards the rear of the car. It would be toward the front if it were a push type. That will give the most movement along with correct leverage. If you can not move the fork at all, either forward or back, with the slave disconnected, it sounds like the bearing is squeezed between the fingers and bearing retainer. If that is the case, it would mean in all likelihood, that the bearing is too tall and a shorter one is required. That is the best I can come up with given what you stated. More details(you can never have enough) might help.

[ColinOpseth]

Thanks for the help, guys.

Here's something that should work better. How's a video?

The clutch fork is obviously moving. Thing is, I'm not sure it's moving enough. I filmed the video myself and couldn't get a measurement of the travel. I was told 15/16" is the travel but I'm not sure if that's at the master cylinder stroke or the stroke at the throwout bearing. No one has really defined that measurement. It's getting almost 1.5" at the master cylinder.

Look at that slave cylinder flex, though.

Now, about the setup. I have cut the master cylinder pushrod. It's been threaded with a rod end on it (3/8x24). I had a lot of air in the lines but I bled the system. I'm assuming there's little air now as the clutch picks up pressure as soon as I push the pedal. I'm wondering if it's a travel issue? i.e. not enough pedal pushing in the master? Anyone have an idea how much that clutch fork should move from rest to disengagement of the clutch disk?

I can feel it now, I'm close.

The link to the movie is: http://www.Opseth.name/colinsfiles/T56Clutch.wmv

[Len]

Hi Colin
Nice vid that does help a lot !!!! I think you may have found the problem all that flex maybe changing changing the effective pull on the t/o bearing and not allowing it to totally release the disc . From what I've read there is not much room for error there.
Thinking you need to shore up the slave as sooner or later that flex will cause a failure and it may solve your problem.
Just thinking with what I see !!!
Len

[ColinOpseth]

Len,
Those are the stock hydraulics. My guess is they flex that much from the factory, but I had no idea they moved that much. I guess there's quite a bit of pressure in that system, eh?

I'm still not getting clutch disengagement. I was thinking about tightening it in a bit more to see if I get disengagement. If I do, I obviously wasn't getting enough push on the fork. From there, I'd probably bleed the system more. I also need to see what the length of the push is, although I have no idea how much effective distance the fork needs to move.

[Len]

really they used those long studs on the slave ?????
But yea I would try dialing the slave down some more or extend the push rod 6 of 1 or 1/2 a dozen of the other or a combination of both .
On other possibility that I have come across was a disk that had rusted to the fly wheel but that truck had sat for 10 or 15 years in the bush???
Len

[ColinOpseth]

Len,
I live in the High Desert. It rains maybe 6-7 times a year here. I doubt that rust would be a problem in my setup.

I bled the system with my wife today. To do that on an LT1 hydraulic setup you have to pump the clutch, a LOT. Or take off the slave cylinder and pump it by hand. I pumped by hand first and got a ton of air out. Still no disengagement. I'm bordering on frustration here. I just can't see why this fricking thing won't disengage. And I've looked everywhere on the Internet and haven't found how far the clutch fork is supposed to travel.

As for the big space, there is a 2" aluminum spacer missing in that video. I tightened the slave cylinder down to 2" from the bellhousing (stock installed depth) and pumped for illustration. This is getting pretty frustrating. My car should be driving right this very second. There's nothing left to do except put the rear wheels on.

[ColinOpseth]

Alright,
So I found a spec for the LT1 T56 clutch fork travel. It should be about 17mm or 0.669291339 inches. That translates to roughly 5/8" of an inch plus a smidge. I measured my travel and am getting closer to 7/8" or plenty more than needed. I'm thinking it's a mechanical issue now, not a hydraulic one. What should I be looking for when I pull this sucker apart? I'll take pictures, obviously.

[Roccosvega]

Is it a diaphragm clutch, if so i remember a friend of mine had smashed the fingers on his pressure plate after installing his.
had something to do with to much travel of the slave.Hopefully that's not what is happening here.Hydraulics have a lot of force.

Robert

[ColinOpseth]

Robert,
Yeah, it's a diaphragm-style clutch. I don't know if I've ever pushed too hard on it and bent it. I'm assuming all of the fingers will be bent when I pull it apart? I'm going to hit the garage and yank the transmission right now. Sucks.

[ColinOpseth]

OK, transmission is out. Here are pictures. From the grease streaking, the clutch fork was definitely engaging the throwout bearing.

[Roccosvega]

These pictures are so close it's really hard to tell whats going on. With the car in gear and the clutch pushed in
would the car roll? Those fingers appear to be OK so it must be an adjustment issue.Look at everything and
measure everything. I believe you will figure it out.

Robert

[HI WINDING MONZA]

Colin, The problem is..............Rust?

The trans collar and splines have to be perfectly clean for it to release right, the disc should be able to slide on the tranny splines like butter and same for the collar on the trans for the throw out bearing to slide easy on.

With the tranny out , put the disc on the splines to check that it does. ( I ran across one once that the trans splines had a burr on it and had to be filed a little.)

Easy fix in your case, just get the trans cleaned real good with wet and dry sandpaper and a light grease on the splines and collar. ( Ps, too much grease is real bad)

Remember next time you store a tranny the splined end has to be greased and covered!

Doug in Az