No clutch engagement on turbo swap

[Ben's Z]

I had some clutch issues before... http://forums.hybridz.org/topic/111283-clutch-fork-wont-move/?hl=collar&do=findComment&comment=1041276

After getting the correct 240mm/2+2/Turbo throw out bearing collar I cannot get the clutch to engage.

 

I have my L28ET up and running, but can't drive it.

 

Exedy Stage 1 Clutch

240mm Turbo collar

Factory 77 5 speed.

 

I have the adjustment clevis damn near backed all the way off the clutch master cylinder rod for the pedal to maximize stroke.  Someone before me had made some homemade slave cylinder rod going to the clutch fork at some point.  In my prior clutch problems I had cut this down in attempt to fix it.  I now made new rod out of some Grade 8 bolt that is about the same length as the rod that worked fine in my car before the engine swap. 

 

With my father in law we both pushed in the clutch and watched the slave cylinder and it just doesn't seem to push the fork far enough to get the pressure plate to engage.  I know I read before there should be a little slop in the rod when the clutch is disengaged, we don't even have this. The fork is very slightly under pressure even without the clutch engaged.  The only way I can think to fix this is to make an even longer slave cylinder rod and forcibly have the fork under pressure at all time.  That or go back to my longer N/A collar to give the slave cylinder a longer "throw".

 

Any help would be great.

[evildky]

To be clear, you problem is the clutch will not disengage, correct?

 

This seems to pop up a lot, aftermarket masters tend to have slightly shorter pushrods, also I've seen the hole in the pedal elongate after 40 years of hard use. Look for play at the hole in the pedal if there is none, and your clevis is adjusted all the way out yet not preloading the TO bearing you might simply need a longer pushrod or longer clevis. Just be sure you have it adjusted with no preload on the to bearing, if the to bearing is pushing on the tines of the PP while at rest you'll burn up that clutch in no time. Less likely but I've had bad pp's that were way way too stiff.

[Ben's Z]

No elongation of the clutch pedal hole. Nothing changed during the swap on the hydraulics side. Never removed the master or slave cylinder from their hoses. I'd like to know what the range of length is on a slave cylinder rod?

 

I don't understand why the slave cylinder rod is so tight yet there isn't enough length with the clutch pedal in for the fork to compress the pressure plate. And I have the master cylinder clevis at the end of the rod.

[evildky]

There should be no pressure from the pedal to the pushrod at rest also should be nearly no play. When you begin pressing the pedal the rod should contact the plunger inside the master almost immediately. The pedal at rest should rest against it's stop. When you depress the pedal the slave should move immediately. The clutch fork at rest should be holding the TO bearing against the tines with the pressure plate with almost no pressure. with all this doing as it should when you press the pedal it should move the slave and push the fork far enough to disengage the clutch. If everything appears as I described and you yet you do not get enough travel either there is air in the lines (it can happen), a weak seal in the slave or master, too short of TO collar (there are 3, and afaik only the mid size is still available), or you got a bad PP, happened to me once, the tines were just bending under full pedal.

[Ben's Z]

I installed a new mc and sc, travel is the same, about 3/4" in the sc rod. I had a friend look at his z and the travel was the same on his working car. I put in a turbo throw out collar bearing. I guess I need to drop the trans and see what is going on.