duragg Posted January 27, 2014 Share Posted January 27, 2014 Yes the throwout collar size is a real nasty trap. There are a bunch of sizes? Story: We had to change a clutch during a race weekend and my "Crew Chief" stayed up all night and got it done to race at 8am. I saw the old Throwout collar and bearing on the ground and he said he just used the new one that came in the box. I literally started to cry... But luckily, they were the exact same size. He didn't know there was a bunch of different sizes. Quote Link to comment Share on other sites More sharing options...
daddydonuts Posted January 27, 2014 Share Posted January 27, 2014 Hope it's not the case, but it could also be the wrong, short, throwout collar. You can get an idea by looking at where the fork sits in its hole, and its angle, when it's pressed against the collar. If it's angled back and sitting at the back of the hole, that's a problem. Could also be an issue with the fork pivot pin, though that would be uncommon. The tranny had a 225mm clutch in it, and that is what it currently has in it as well. I'll look at the pivot pin tonight. Quote Link to comment Share on other sites More sharing options...
NewZed Posted January 27, 2014 Share Posted January 27, 2014 The pressure plate height is the key. Apparently the earlier 240Z's had a tall 225 mm plate, the pressure plate got shorter for later 225 mm clutches, and the 240 mm has a taller pressure plate. Easy to get a mis-match of parts. This link illustrates. You can see the early Type A 4 speed has a short collar. The later more common Type B uses a tall one. And there are variations in between, and after. Not really clear what Nissan was doing. http://zparts.com/zptech/articles/trans_swap%20parts/4tobear_specs1.html Quote Link to comment Share on other sites More sharing options...
z240 Posted January 27, 2014 Share Posted January 27, 2014 Thought we solved this "what collar height to use???" thing already. The carefully guarded 'secret' is to choose a collar that gives you ~92mm of total height from the flywheel friction surface to where the fork touches the fingers on the collar. Measure up to the PP fingers, then see how much more you need to get to 92, then choose the closest collar length with a throwout bearing on there to get to 92mm. Or is it 95mm...hmmm.... Dang interweb.... Not enough to remember that its been solved, also have to remember how to find it again when you actually need it.... ok, lots of discussion about it here. It's 92 mm http://www.classiczcars.com/forums/engine-drivetrain-s30/47279-l28-toasting-my-240z-clutch.html Quote Link to comment Share on other sites More sharing options...
daddydonuts Posted January 27, 2014 Share Posted January 27, 2014 The pressure plate height is the key. Apparently the earlier 240Z's had a tall 225 mm plate, the pressure plate got shorter for later 225 mm clutches, and the 240 mm has a taller pressure plate. Easy to get a mis-match of parts. This link illustrates. You can see the early Type A 4 speed has a short collar. The later more common Type B uses a tall one. And there are variations in between, and after. Not really clear what Nissan was doing. http://zparts.com/zptech/articles/trans_swap%20parts/4tobear_specs1.html That has to be it...I appreciate your knowledge! Quote Link to comment Share on other sites More sharing options...
NewZed Posted January 27, 2014 Share Posted January 27, 2014 (edited) No problem. z240 is right on the 92 mm number. Several people have concluded that independently. Seems to work. Edit - It's funny how many odd numbers Nissan has in the FSM's. Won't help you but they show that the 225 mm 1972 pressure plate is 44 mm from friction surface to diaphragm surface, 1976 is 33-35 mm. They don't give the throwout collar distance though. Just a curiosity. Edited January 27, 2014 by NewZed Quote Link to comment Share on other sites More sharing options...
adivin Posted June 8, 2022 Share Posted June 8, 2022 Time warp to present... Can't the same thing be accomplished if you have an adjustable slave cylinder as getting a taller collar? Quote Link to comment Share on other sites More sharing options...
JMortensen Posted June 8, 2022 Share Posted June 8, 2022 (edited) Seems like it should do the same thing. IIRC the adjustable slave has about 1" of threaded section. Couldn't tell you how much of that is unusably short, I seem to remember running around the middle of the adjustment. Could probably get a longer bolt and cut and make a new pin if necessary. EDIT-at some point the angle on the fork is going to be bad and that might cause wear... Edited June 8, 2022 by JMortensen Quote Link to comment Share on other sites More sharing options...
adivin Posted June 8, 2022 Share Posted June 8, 2022 I'm running into the problem that others have had of tying to get the clutch to disengage without preloading the TO bearing on the PP. I can adjust the slave, but it I think it is putting constant pressure on the PP. It would seem using a taller collar puts me in the same situation as adjusting the slave. The solution would be more stroke from the slave. I currently have a 5/8 MC and I think a 11/16 slave. Quote Link to comment Share on other sites More sharing options...
lowrider Posted June 13, 2022 Share Posted June 13, 2022 On 6/8/2022 at 5:51 PM, adivin said: I'm running into the problem that others have had of tying to get the clutch to disengage without preloading the TO bearing on the PP. I can adjust the slave, but it I think it is putting constant pressure on the PP. It would seem using a taller collar puts me in the same situation as adjusting the slave. The solution would be more stroke from the slave. I currently have a 5/8 MC and I think a 11/16 slave. The later S30's used 3/4" slave cylinders. I always had issues with my clutch setup engaging at the very bottom of the pedal stroke, and like you, didn't want the TO bearing touching the PP all the time. I made the switch to a 11/16" slave from an '89 240sx and it corrected the issue. My clutch now disengages/engages in the middle to upper end of middle of the pedal stroke. I would confirm what size slave cylinder you have, and then size it a little smaller. Quote Link to comment Share on other sites More sharing options...
adivin Posted June 13, 2022 Share Posted June 13, 2022 1 hour ago, lowrider said: The later S30's used 3/4" slave cylinders. I always had issues with my clutch setup engaging at the very bottom of the pedal stroke, and like you, didn't want the TO bearing touching the PP all the time. I made the switch to a 11/16" slave from an '89 240sx and it corrected the issue. My clutch now disengages/engages in the middle to upper end of middle of the pedal stroke. I would confirm what size slave cylinder you have, and then size it a little smaller. Over the weekend I installed a new OEM (Nabco) 11/16 slave. It didn't make much difference. I made a few more turns on the MC by the pedal and it got it to where I can drive the car. I am almost at the end of adjustment there. Engagement is still really close to the floor. I don't know where to go from here. I suppose a larger MC like Wilwood perhaps would get me more travel at the slave? I might just adjust the slave more beyond the point that I should. Quote Link to comment Share on other sites More sharing options...
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