Clutch help 4 to 5 tranny swap

[five&dime]

Actually, the transmission doesn't matter. Different years of cars used different height pressure plates and had throwout bearing collars to suit whichever pressure plate was used. The drive plate and T-O bearing itself were all the same regardless of the other parts.

Unfortunately, I can't think of any way to verify whether this might be your problem without dropping the transmission and measuring parts. But your description of the problem certainly sounds like this is a likely possibility. Especially how the PO used every possible thread on the pushrod and such to try to get enough travel. Sounds like you have both a short collar and a short pressure plate.

Here's a page that helps describe the issue with pictures:

http://zparts.com/zptech/articles/trans_swap%20parts/4tobear_specs1.html

This actually may not be the case in all scenarios. I just went through this with my 510. It has a roadster 5 speed. I was told by all the experts that if I had the roadster pressure plate, clutch disc, etc then I would also need the roadster sleeve and bearing. The consensus was regardless of the trans, you use the same pp, TO and clutch. This was not true for my car though. I installed the roadster sleeve. Put my trans back in and no go

I had to use a longer sleeve with the roadster bearing and everything is perfect now

I should have listened to my dad all along. When the everything is installed, the clutch fork should be coming through the boot at the middle/closer to the front of the bellhousing (closest to the block). When all together, you should have a slight bit of play before the slave cylinder starts to engage the clutch.

If the sleeve is too short, the fork will be closest to the back of the hole and will not have enough room to engage. Which is what happened to me.

This is also a chart for the T/O's. The dimensions are in MM.

30501_Chart.pdf

Edited April 2, 2009 by five&dime

[ktm]

It is the case for 240zs and the 280z/280zx 5-speeds; this is discussed extensively. I have a 1992 300zx twin turbo five speed in my 1972 240z and I am using the 280z T/O collar and 280z pressure plate. I used the SAME pressure plate and collar when I was running a 1971 4-speed, 1974 4-speed, 1978 5-speed, and 1992 z32 5-speed behind the engine.

There is insufficient throw at the slave cylinder. This could be caused by a leaking slave cylinder, leaking master cylinder, cracked pivot ball, cracked fork, air in the lines, bad pressure plate (my ACT PP rivets holding the diaphragm spring stretched on me and caused similar problems).

Edited April 6, 2009 by ktm

[WalterMondale]

Couldn't PaPa Duece crawl under the car, unbolt the slave cylinder, then measure how much throw there is on the fork, to verify if he really needs to drop the transmission?

Also, is it not possible the PO installed the wrong or short slave cylinder pin (which would not fully push the fork back)?

At least he would be able to see at this point that something is amiss in geometry/ mechanics.