Slave Cylinder Over-Extending

[johnstronaut]

1976 280z coupe, 5-speed late S-30 Transmission

      A few months back I had an issue where my Z wouldn't go into gear while running. After changing both the slave and master cylinders and having the problem continue, it was time to drop the trans. Turns out where the clutch fork meets the pivot ball had completely broken and wasn't allowing the clutch to fully disengage.

      I always get a bad case of the while-im-at-it's whenever I do anything, so I changed the pilot bushing, flywheel, clutch, pressure plate, throw out bearing and of course the shift fork. After reassembling, the slave is now over extending and ends up blowing out because it goes too far.  By the time the throw out bearing reaches the pressure plate, the slave rod is nearly fully extended (seeing this through where the rubber boot goes). The rod doesn't return when the clutch is released, but the clutch pedal is adjusted to FSM specs. 

       At this point I'm just looking for some brainstorming, I'm all mixed up now and would like to get back on track. Absolutely anything you guys know about anything clutch related just blurt it out. What was supposed to be a simple fix is driving me crazy. I'm no Z expert so I could be missing something really simple. 

    Thanks guys! 

[Zed Head]

 

28 minutes ago, johnstronaut said:

  I changed the pilot bushing, flywheel, clutch, pressure plate, throw out bearing and of course the shift fork. After reassembling, the slave is now over extending and ends up blowing out because it goes too far.

Sounds like you got a short throwout bearing sleeve with a short pressure plate, when you replaced your parts.  The height of the pressure pate plus the height of the sleeve needs to be within a certain range.  92 mm from the flywheel to the ears of the sleeve seems to be about mid-range.  If you search "92 mm throwout collar" on the site you'll probably find some discussion about it.

You might be able to make it work by extending the rod but the "proper" way to do it is to take the transmission back out and use the right sleeve.  AKA "collar".

Here's an example of the different sleeves.

 

[siteunseen]

Some good reading...

https://www.google.com/search?rlz=1C1BOFA_enUS494US494&ei=O2HXW6iCK6Sk_Qb-u7LQBA&q=92+mm+throwout+collar+classiczcars.com&oq=92+mm+throwout+collar+classiczcars.com&gs_l=psy-ab.3...13270.13270..14501...0.0..0.71.71.1......0....1..gws-wiz.2H4un9uboWI