I recently went to replace the clutch slave cylinder on my 1972 240z with a 4 spd transmission becasue the clutch was slipping on the street. By slipping I mean that with the pedal fully depressed the car would still try to lurch forward when in gear. Neutral was fine. Ive only put about 1200 miles on the car since ive had it but its always been difficult to shift.
I bled the clutch slave cylinder that was already installed and tried adjusting the slave cylinder rod with no improvement in the clutch engagement, both feel or physically disengaging the clutch all the way. The fluid coming out of the old system was pretty black so I decided to replace the slave thinking there was a bad seal, it was super cheap and already apart.
After removing the old slave cylinder and testing out the clutch release fork I found very little resistance and I could easily move the fork through, what looks to be, the full range of its travel with just my hand. Video attached, im thinking I need a new pressure plate. OR the PO has an aftermarket clutch installed and did not use the longer throw out bearing I've read you need for a centerforce
https://youtu.be/keKrmlkZRxk