Guest Anonymous Posted July 13, 2000 Share Posted July 13, 2000 Hi everyone, I purchased a Z built by one of Scarabs employees a few months ago and recently started working on it. The car is in excellent condition and was garaged for about 10 years, the last owner started the car every week and only drove it once a month. The car is equipped with a 350, old school Hayes 3 finger style clutch assembly and Super T 10 tranny. Now the problem: When I first purchased the car, it was very difficult to get into gear and started slipping when driven at normaly on the freeway, so I tried adjusting it and found that it couldn't be adjusted any more, so figuring that the car sat for 10 years I assume that the clutch or one/all of it's parts went bad after not being used. After removing the transmission, disc and pressure plate, everything looked brand new except the flywheel which had blue streaks on it. So yesterday, I had my flywheel resurfaced, installed a new Centerforce II clutch kit, new slave cylinder and the car drove fine. Now the problem is starting again and it's difficult to get into gear and slipping on the freeway again. Help,,,,, Thanks, Hoover Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted July 13, 2000 Share Posted July 13, 2000 Glad to be here on Hybrid Z!!! The car is equipped with a steel braided line from the m/c to the s/c, these don't wear out, do they? My m/c is from tilton. I just found out that Scarab used a slave cylinder from a Datun 1200. I was thinking that it could be the rear main seal or a seal on the tranny leaking a bit of oil on the disc., but the old set looked absolutely perfect and there isn't any smell over burning oil. The clutch pedal has also sunken a bit, so I'm going to remove the m/c and check for any wear and tear on the seals..... Give me all the advice you've got guys... Thanks, Hoover www.gotumph.com esell for race cars Quote Link to comment Share on other sites More sharing options...
Drax240z Posted July 13, 2000 Share Posted July 13, 2000 Heres a quick idea for you. I'd imagine its allready been done, but you never know, sometimes you overlook the simple things. Have you changed out that 10 year old fluid? Bled the system well? I'd imagine you have allready, but what the hay. ------------------ Drax240z 1973 240z - L28TURBO transplant on the way! http://members.xoom.com/r_lewis/datsun.html Quote Link to comment Share on other sites More sharing options...
Guest mattrp Posted July 14, 2000 Share Posted July 14, 2000 Well, I've been reading and somehow I managed to avaid this problem completely. I am also using the stock datsun master and slave cyclinder on my T-5. I just cut up some 1/16" sheet steel and bolted the sucker on. Then I cut the little rod for the slave cylinder till it was very snug in the hole, and voila. I still have the rubber stop at the bottom of the clutch pedal, and in fact, I adjusted my clutch pedal ride height to be even with my brake pedal, and I am still fine. I did change my fluid to synthetic. I am also using a stock pressure plate and disc. My guess is that your problems stem from that centerforce two clutch. I'll bet those centrifugal weights, etc, are causing you some problems. I'd personally modify the clutch fork a little, make it shorter. I hopr you guys get this figured out. I know the feeling, being so close, but still not done. My new motor has been sitting on the stand for two weeks, the cars done, and I'm waiting for the stupid tranny to come back from the shop. This SUCKS! Matt 72 500Z Quote Link to comment Share on other sites More sharing options...
Guest mattrp Posted July 14, 2000 Share Posted July 14, 2000 Well, I've been reading and somehow I managed to avaid this problem completely. I am also using the stock datsun master and slave cyclinder on my T-5. I just cut up some 1/16" sheet steel and bolted the sucker on. Then I cut the little rod for the slave cylinder till it was very snug in the hole, and voila. I still have the rubber stop at the bottom of the clutch pedal, and in fact, I adjusted my clutch pedal ride height to be even with my brake pedal, and I am still fine. I did change my fluid to synthetic. I am also using a stock pressure plate and disc. My guess is that your problems stem from that centerforce two clutch. I'll bet those centrifugal weights, etc, are causing you some problems. I'd personally modify the clutch fork a little, make it shorter. I hopr you guys get this figured out. I know the feeling, being so close, but still not done. My new motor has been sitting on the stand for two weeks, the cars done, and I'm waiting for the stupid tranny to come back from the shop. This SUCKS! Matt 72 500Z Quote Link to comment Share on other sites More sharing options...
Guest mattrp Posted July 14, 2000 Share Posted July 14, 2000 Well, I've been reading and somehow I managed to avaid this problem completely. I am also using the stock datsun master and slave cyclinder on my T-5. I just cut up some 1/16" sheet steel and bolted the sucker on. Then I cut the little rod for the slave cylinder till it was very snug in the hole, and voila. I still have the rubber stop at the bottom of the clutch pedal, and in fact, I adjusted my clutch pedal ride height to be even with my brake pedal, and I am still fine. I did change my fluid to synthetic. I am also using a stock pressure plate and disc. My guess is that your problems stem from that centerforce two clutch. I'll bet those centrifugal weights, etc, are causing you some problems. I'd personally modify the clutch fork a little, make it shorter. I hopr you guys get this figured out. I know the feeling, being so close, but still not done. My new motor has been sitting on the stand for two weeks, the cars done, and I'm waiting for the stupid tranny to come back from the shop. This SUCKS! Matt 72 500Z Quote Link to comment Share on other sites More sharing options...
74_5.0L_Z Posted July 14, 2000 Share Posted July 14, 2000 Did you change the rubber line going to the slave cylinder? If not, it is possible that the rubber line has deteriorated, and has loose particles on the inside. The loose particles can act as a check valve and prevent the clutch slave cylinder from bleeding down when then pedal is released. The residual pressure will prevent the clutch from fully engaging. ------------------ Quote Link to comment Share on other sites More sharing options...
pparaska Posted July 14, 2000 Share Posted July 14, 2000 WOW, Mike, that was an impressive diagnosis. I read the first post and I had no clue. Your analysis makes alot of sense! Quote Link to comment Share on other sites More sharing options...
Guest Frank280z Posted July 14, 2000 Share Posted July 14, 2000 Hey Hoover, Welcome to HybridZ. I'm going through the same problem myself. First off; remove that stopper under the clutch pedal assy. My setup is also brand new. Master cyl /slave cly. centerforce dual. Even have the stainless hose to the slave cyl. I'm using a Datsun s.c. with a fab'd bracket. My dissengagement is fine now that I removed the stopper. But the engagement is now still slipping. I'm going to put a h.d return spring to help this. I'll tell you if it works. Believe me I know what your'e going through. I also have a topic started in the transmission section. "Major Help..." Frank ------------------ Build it. Drive it. Improve it. Quote Link to comment Share on other sites More sharing options...
pparaska Posted July 14, 2000 Share Posted July 14, 2000 You guys aren't mentioning the diameters of the M/C or S/C, but I know this is an issue with the 6.2:1 pedal ratio of the Z, especially if you are using a stock length clutch fork. Some people solve the excessive pedal throw issue with a modified clutch fork (S/C point closer to the pivot) or a larger diameter M/C. There are aftermarket Tilton, Girling, AP racing units that come in larger than stock (5/8") diameters. I've had a few in my car trying to get the clutch to work. I started with a 1" AP Racing master cylinder (short one to keep the W/W bottle in stock location) but it was too large, and made the clutch pedal feel like a quadracep exercise machine. If anyone is interested, I have this unit for sale. It might work better for a fork type clutch setup (I have a hydraulic T/O bearing). Anyway, having to get rid of the bottom pedal stop to disengage the clutch, and then having to remove the top stop and add a spring leaves you with a VERY long clutch pedal throw. The car would be much more fun to drive if you used a larger M/C diameter and shortened the throw needed for full clutch actuation, fully disengaged to fully engaged. Quote Link to comment Share on other sites More sharing options...
Guest mattrp Posted July 22, 2000 Share Posted July 22, 2000 Hey guys, I just went through the hassle you speak of. When I resinstalled my new motor and tranny and clutch set, my clutch also *appeared* not to disengage. So I moved the pedal to the furthest point, and I bled the cylinder, custom machined a pushrod for the slave cylinder from a 75mm bolt, and then tried it. Well, I could get the tranny in gear, but the clutch didnt really engage at all. So I put it all back to wear the lower rod was just snug in between the slave cylinder and the throwout fork. VOILA, damn thing worked. My hunch is that the input shaft was jammed slightly in the pilot bearing, or that the tranny was just kinda stuck. Make sure you actually move the car around a little before giving up on your clutch system. The datsun setup is able to provide MORE than enough throwout. Hope that helps. Matt 72 500Z Quote Link to comment Share on other sites More sharing options...
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