Flexicoker Posted August 31, 2008 Share Posted August 31, 2008 I've got an L28 and 5-speed out of an '81 in my '73 Z. The flywheel, throwout bearing and clutch release fork are from the 280ZX, the flywheel has been surfaced, and installed with a sprung 6-puck and pressure plate from clutch net. The slave and master cylinders are from the 240. I just got it running for the first time the other day, and its hard to get into gear, and grinds going into reverse unless I force it in, however when its in gear the clutch doesn't really engage until its about 2/3 released. I'm about 99% its the clutch dragging. The slave cylinders from the 2 cars seem to be the same which leads me to believe the master cylinders must be different and I'm not getting enough travel. the pedal has been adjusted to get the maximum possible throw, and its been bled. Other scenarios: To much material was taken off the flywheel, or I got incorrect parts from clutch net. would the differences in the clutch masters be enough to cause this? and if so will the 280ZX version bolt up? Quote Link to comment Share on other sites More sharing options...
Nigel Posted August 31, 2008 Share Posted August 31, 2008 Which throwout bearing sleeve and clutch (for what year and model) are you using? The sleeves are different lengths (3 lengths that I'm aware of) and it has to match the clutch. Nigel '73 240ZT Quote Link to comment Share on other sites More sharing options...
Flexicoker Posted August 31, 2008 Author Share Posted August 31, 2008 the throwout sleeve is also from the '81, I bought the engine tranny togethor out of a wrecked car. The only thing that has changed from stock is the surfacing done to the flywheel, the clutch, and the PP, and using the '73 hydraulic parts. Clutchnet says the clutch is for '73-'83, so its a possibility then that the clutchnet clutch is not actually for an '81. Quote Link to comment Share on other sites More sharing options...
AK-Z Posted August 31, 2008 Share Posted August 31, 2008 did you just install everything recently? You might just need a new clutch master. Seals could be worn out Quote Link to comment Share on other sites More sharing options...
Flexicoker Posted August 31, 2008 Author Share Posted August 31, 2008 clutch master and slave have been recently rebuilt with new seals, and don't show any signs of leaking, but it still might be worth it to try a new one. One thing I noticed though was that I can stick my finger into the slave cylinder and slowly push the piston back. I dont know if I should be able to do that or not. Does anyone know if the 280ZX and 240Z clutch masters are interchangeable and if they have the same bore size? Quote Link to comment Share on other sites More sharing options...
Careless Posted August 31, 2008 Share Posted August 31, 2008 As long as the slave isnt leaking at the piston, then pushing it back with your finger is ok. Mine does not leak, and extends the fork fully. If I squeeze the piston pin and body together with my hand, it will work it's way back slowly (and with a bit of pain to my thumb, due to the piston pin being small). Quote Link to comment Share on other sites More sharing options...
Careless Posted September 1, 2008 Share Posted September 1, 2008 just a note, my flywheel was machined as well and the previous owner said that ever since the clutch was done it felt funny going into gear. I later read on some published repair info that VG30 flywheels aren't supposed to be machined that much for whatever reason. (can't recall). but I've been told otherwise by VG Owners. My car had trouble going into reverse sometimes, and I could not get it into gear without grinding. I adjusted the pedal rod and bled the system, and I had the fork moving so much that the throw-out bearing collar would rub on the pressure plate fingers. it's my suspicion that it was related to the flywheel, which looked to have hairline cracks and heatwear marks. I've yet to install my Fidanza unit and stainless line to replace everything because I can't get a broken manifold stud out of the head. another thing to note is that while you can have a friend press the clutch pedal and experience full pedal depression and slave-piston expansion, you may be experiencing the opposite under load, with the input shaft spinning it may be binding on the collar or the slave may not be functioning properly. I also noticed my pilot bushing had a weird grind mark on it. perhaps from install or maybe they could not fully remove the one that was in there at the time. Quote Link to comment Share on other sites More sharing options...
AK-Z Posted September 1, 2008 Share Posted September 1, 2008 Have you tried pumping the clutch pedal and then adding fluid? When I driven the car for a while, I have to pump the clutch to build presure in the line. Oh is there some resistence on the pedal? Quote Link to comment Share on other sites More sharing options...
Flexicoker Posted September 1, 2008 Author Share Posted September 1, 2008 ya, I've tried pumping it. One thing I just remembered... when I first put installed the engine/tranny I had my dad go under the car and turn the driveshaft by hand so I could set the pedal position. So at that point it was not dragging, but the first time I drove it it was dragging. Also right after we bled it it worked for about 2 seconds, and then would grind going into reverse again. I'm going to go work on it in a bit, maybe I'll figure it out, I really don't want to have to yank the transmission. Quote Link to comment Share on other sites More sharing options...
Flexicoker Posted September 1, 2008 Author Share Posted September 1, 2008 ok, problem is still unsolved. We grabbed the clutch fork with vice grips, and pulled it an extra 1/4" maybe to the end of its travel, still drags. Pulled the transmission. The installed height of the PP fingers is 1.366", within range according to the FSM. clutch fork has no visible cracks, and the throwout bearing is fine. What else could it be? The dragging is not that bad, you can still turn the driveshaft by hand... barely. But its enough to grind like madness going into reverse and make it hard to shift. We might put in the ancient clutch and PP that we took out of it and see what happens. Quote Link to comment Share on other sites More sharing options...
rags Posted September 2, 2008 Share Posted September 2, 2008 Might be completely unrelated but I had the same problem after swapping a trans. My problem turned out to be the input shaft not being machined the same as the input shaft on the old trans. The end of the shaft that goes into the pilot bushing was not as long as the old trans so it would drag on the pilot bushing. The way I found this was by loosening the trans to engine bolts, then the clutch would disengage. I pulled the trans out and measured the length of the small diameter of the input shaft and there was a difference. A very small difference but there was a difference. I guess I could have just tried to push the pilot busing in a little further but decided to change it. After I changed it, no more clutch problem. Oh and yes, I did have the trans in and out a few times. Even put the old one back in to make sure I wasn't going crazy! Quote Link to comment Share on other sites More sharing options...
Flexicoker Posted September 2, 2008 Author Share Posted September 2, 2008 I figured it out! Trouble is... I'm incredibly stupid. I accidently ordered a clutch for an '83, my engine/tranny is from an '81... They have a different installed distance from the flywheel to the PP fingers. So now I have a barely used clutch that won't work, and I probably can't return. Commence hunt for an '82/'83 throwout collar!! Quote Link to comment Share on other sites More sharing options...
AK-Z Posted September 2, 2008 Share Posted September 2, 2008 lol. that was mentioned in the 2nd post. Quote Link to comment Share on other sites More sharing options...
Flexicoker Posted September 2, 2008 Author Share Posted September 2, 2008 haha, I know. That came up when I searched beforehand too. I sort of ignored it because everything was from the same car, and I assumed I ordered the clutch for the correct year. Assumption is the mother of all F-ups. Thanks for the help everyone Quote Link to comment Share on other sites More sharing options...
woldson Posted September 2, 2008 Share Posted September 2, 2008 Man sorry to hear that..... What are slightly used clutchs going for? I have an 83zx, hint hint. Quote Link to comment Share on other sites More sharing options...
Flexicoker Posted September 3, 2008 Author Share Posted September 3, 2008 haha, I'm not sure if I'm ready to sell it yet, and when/if I do I'd like to get close to what I paid for it because I still would need to buy another, and its only driven a few miles, so its basically new. I learned a couple new things today though... according to the microfiche, '81-83 have the exact same throwout sleeve. The clutch net clutch, supposedly for an '83, has an installed height that matches the specs in the '82 service manual. However, the installed height of the stock one that is in the car (should be '81) does not match what the '82 service manual says. BUT, the microfiche says that '81-82 have the same PP, and that '83 has a different one. So now I'm really confused. I'm going to drive it with the stock clutch for now, but I do need to get this figured out so I can put a good clutch in. Quote Link to comment Share on other sites More sharing options...
Nigel Posted September 3, 2008 Share Posted September 3, 2008 Do you know for sure that the clutch in the '81 was factory original? The 225mm clutch comes in 2 depths. According to my '73 service manual, the diaphragm spring to flywheel height is between 43 to 45 mm. The '82 service manual has a spec of 33 to 35 mm. The 240mm clutch has a spec of 37.5 to 39.5 mm. So that would mean that the 240Z 225 mm clutch would have the shortest sleeve, followed by the 240mm clutch sleeve, and the 280ZX 225mm clutch sleeve would be the longest. Here's a link to a page that shows the 280ZX 225mm and 240mm sleeves... http://www.forgeracing.com/240z_race_car/ Perhaps the '81 ZX had an early Z clutch installed which would have a sleeve too short to operate the new clutch you bought? What are the measurements that you took of the two clutches? Nigel '73 240ZT Quote Link to comment Share on other sites More sharing options...
Flexicoker Posted September 4, 2008 Author Share Posted September 4, 2008 could the 2+2 have a 225mm clutch but with a taller pressure plate? Maybe thats the issue.... Quote Link to comment Share on other sites More sharing options...
AK-Z Posted September 4, 2008 Share Posted September 4, 2008 as far as the bearing reaching the PP. bearing and PP have to match. Flywheel should be the same for all L28 IIRC. Quote Link to comment Share on other sites More sharing options...
proxlamus© Posted September 4, 2008 Share Posted September 4, 2008 http://zparts.com/zptech/articles/trans_swap%20parts/4tobear_specs1.html Check out that link Quote Link to comment Share on other sites More sharing options...
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