heavy85 Posted June 7, 2005 Share Posted June 7, 2005 She's alive ... well sort of. After a huge ordeal involving various machine shops a couple of blocks various stripped threads and an unplanned complete engine rebuild (but I did manage to get a complete turbo motor for $125 in case the tripples dont work out) plus a new synchro in tranny and LSD Saturday I started it for the first time. Engine ran great until it sprang a water leak but no big deal just thermostat cover - but didn't get to drive it any other than inched it forward to make sure the clutch and tranny engaged. Anyway when I installed the motor I noticed that it was very difficult to get it any closer than about 1" from the front of the tranny but didn't think too much of it. Then later Saturday after realizing that the mystery bolt that had been sitting on my workbench for a while was the one which holds 5th gear on I took the tranny out to install the missing bolt. When I went to put the tranny back in I noticed the same fitup issue and actually had to draw the two together with the mounting bolts. Realizing that this still did not seem right I pulled it back off started scratching my head. So here is what I have and am desperate to get this in so I can test drive it finally so if you got any ideas please shoot them my way. '82 Turbo block ?? l28 crank from a non turbo F54 larger diameter 280Z clutch and flywheel Early 'Competition' 5 speed If you draw the two completely together then there is pressure between the throughout bearing and the clutch which I think there shouldn't be any but that's just in the very last bit of drawing them together? Also seems like some of the difficulty in getting them together (and appart for that matter)before just the last bit when the throughout bearing starts engaging the clutch is in the pilot bushing but cant tell for sure. Now I have another 5 speed and the bellhousings are identical and a 240 clutch which actually uses a THICKER flywheel and THICKER clutch and THICKER throughout bearing. So I've got the skinniest pieces in there and it still seems too thick. This same set-up was in the car before but I can't say for sure it was ever right. Any advice??? Thanks Cameron Quote Link to comment Share on other sites More sharing options...
Here comes trouble Posted June 7, 2005 Share Posted June 7, 2005 Cameron... the transmission mainshaft is splined to fit into the flywheel and crank splines of the engine and sometimes this alignment takes some fine tuning before that last inch of space comes together for tranny and engine by turning the drive shaft slightly to align the splines of the engine and tranny so the two can properly splined together Quote Link to comment Share on other sites More sharing options...
Mike kZ Posted June 7, 2005 Share Posted June 7, 2005 Also make sure the input shaft fits into the pilot bushing. Check the length of the input shaft, make sure it's not too long. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted June 7, 2005 Share Posted June 7, 2005 I've had some really tight pilot bushings before. I bet that is your problem. Sometimes even when you use a clutch alignment tool the clutch disc can still be a little bit off, and that causes problems. I would say if you got the transmission on and you were able to inch the car forward, don't worry about it. If you do still want to worry about it, check for free play at the throwout fork. If you have the wrong throwout bearing sleeve on the transmission then there would be NO freeplay at the fork. So you got the comp trans fixed, eh? Did you use a Porsche synchro? I was talking to somebody else about that and they confirmed the Porsche thing and said that Don Potter has used Porsche synchros on the Comp boxes. Quote Link to comment Share on other sites More sharing options...
zcarnut Posted June 7, 2005 Share Posted June 7, 2005 ...I've had some really tight pilot bushings before. I bet that is your problem.... I have seen where people installed the pilot bushing incorrectly by using just a hammer to drive it into the rear of the crank. This caused the bushing to “bellmouth†reducing its internal diameter enough that the tranny input shaft was binding during assembly. The proper method is to use a correctly sized bearing/bushing insertion tool with the hammer. ...Sometimes even when you use a clutch alignment tool the clutch disc can still be a little bit off, and that causes problems.... Yeah. Most of those plastic clutch alignment tools fit too loose into the pilot bushing. This results in the clutch disc sagging down under its own weight when the alignment tool is inserted into the pilot bushing. Always confirm that the clutch disc is centered by measuring the distances to the diaphragm fingers with a caliper. I always eyeball the clutch disc center hole with the bushing after the pressure plate bolts have been snugged down and the alignment tool has been removed. It’s amazing how accurate you can determine the centered location of the disc. Quote Link to comment Share on other sites More sharing options...
heavy85 Posted June 7, 2005 Author Share Posted June 7, 2005 If you do still want to worry about it' date=' check for free play at the throwout fork. If you have the wrong throwout bearing sleeve on the transmission then there would be NO freeplay at the fork. So you got the comp trans fixed, eh? Did you use a Porsche synchro? I was talking to somebody else about that and they confirmed the Porsche thing and said that Don Potter has used Porsche synchros on the Comp boxes.[/quote'] The tight fit is probably just the pilot bush which I did not change and the 'sloppy' plastic 'alignment' tool is probably a little off. OK so that explains the first problem why it gets tight when they are about 1" appart, but doesn't explain why there is NO freeplay in the throwout bearing once they are drawn together. The bearing sits all the way back against the bellhousing so I dont see how the bearing sleeve affects this? It bottoms out at just that last maybe 1/8" or less as you draw the trany and engine together. I actually replaced the synchro myself with one from Ralleye (I think that's it) which is a Datsun Roaster place that sells them. Thanks Cameron Quote Link to comment Share on other sites More sharing options...
JMortensen Posted June 7, 2005 Share Posted June 7, 2005 The longer the sleeve is the further towards the pp the throwout bearing sits. So if you have a long sleeve then you need a short pressure plate (like the 240 setup) and if you have a shorter sleeve you can use a taller pp (280). If you don't have free play in the throwout fork it means that the bearing is contacting the pp when the two are bolted together, basically depressing the clutch just a little bit all the time. This is not good. This free play measurement is not something you'll be able to tell without pushing pretty hard on the fork. Two fingers trying to jiggle it back and forth won't do it. If you're using a 280 pp then you need a 280 sleeve. As long as the pp and sleeve match you should be good to go. Quote Link to comment Share on other sites More sharing options...
Here comes trouble Posted June 7, 2005 Share Posted June 7, 2005 Check these Z throw out bearing comparisons http://www.zparts.com/zptech/articles/trans_swap%20parts/4tobear_specs1.html Quote Link to comment Share on other sites More sharing options...
heavy85 Posted June 7, 2005 Author Share Posted June 7, 2005 The longer the sleeve is the further towards the pp the throwout bearing sits. So if you have a long sleeve then you need a short pressure plate (like the 240 setup) and if you have a shorter sleeve you can use a taller pp (280).... This free play measurement is not something you'll be able to tell without pushing pretty hard on the fork. Two fingers trying to jiggle it back and forth won't do it Well since the TO bearing rests back against the bellhousing I dont see how the sleeve could have anything to do with it? Also, what do you mean 'Two fingers trying to jiggle it back and forth won't do it' because that was my judge that it was too tight. Maybe it's not too tight I just figured if there was no visibly play with a light touch that it was too tight. How exactly then do you determine free play? Thanks Cameron Quote Link to comment Share on other sites More sharing options...
JMortensen Posted June 7, 2005 Share Posted June 7, 2005 You remember inside the bell housing how there was that collar that sits around the input shaft? And you remember how the fork and throwout bearing sat on that collar? Well think of that area when the transmission is installed. The input shaft is stuck into the pilot bushing. The clutch is on the splines on the input shaft. The end of the pp sits over the clutch and the fingers of the pp are over the collar part. There isn't enough room to have the wrong throwout bearing collar on there. You've only got a couple inches between the back of the bellhousing and the pp when it's all together. So if your throwout bearing sleeve is too long, then there isn't enough room to bolt it all together. When you do, the throwout bearing is already contacting the pp, which means the clutch is always depressed a little bit. Ruins throwout bearings really fast, and the clutch will slip really bad too. As far as checking goes these pieces don't move that easy. I went through this same thing about 10 years ago when I first put my Z together. My friend and I had just installed the transmission and had gone through the same 240 to 280 conversion crap. He tells me to check for free play and I grabbed with 2 fingers. Nope, no free play. He thinks he put the wrong sleeve in and we're both bummed. He came over to double check it and grabbed the end of the fork with his hand and was able to move it back and forth 1/4" or so. Then I got a verbal whoopin'... Don't worry, without some sort of leverage you won't be able to compress the pp springs, so jerk it back and forth hard and see if there is some free play in there. Quote Link to comment Share on other sites More sharing options...
heavy85 Posted June 9, 2005 Author Share Posted June 9, 2005 Woo-Hoo It's finally done. Should test drive it tomorrow (fingers crossed). Ended up being the @#%$@!'in POS 'alignment' tool and I use the work alignment loosely because it was too sloppy to properly align anything. All is good now and for some reason I now have plenty of free play (even just wiggling with two fingers). Thanks for all the help. Cameron Quote Link to comment Share on other sites More sharing options...
2126 Posted June 9, 2005 Share Posted June 9, 2005 Woo-Hoo It's finally done. Should test drive it tomorrow (fingers crossed). Ended up being the @#%$@!'in POS 'alignment' tool and I use the work alignment loosely because it was too sloppy to properly align anything. All is good now and for some reason I now have plenty of free play (even just wiggling with two fingers). Thanks for all the help. Cameron Well done....one more box checked off the to do list!!! I had the same issue when installing my late model 5 speed. Blast thoughs POS plastic F'in misalignment tools anyway! Quote Link to comment Share on other sites More sharing options...
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