Justinp551 Posted February 25, 2012 Share Posted February 25, 2012 Whats the common practice on installing a new flywheel and clutch regarding locktite? I have heard to just torque appropriately and then I have also read to torque and locktite the flywheel bolts. Also what is the common practice for the 9 pressure plate bolts? Quote Link to comment Share on other sites More sharing options...
Perfect240z Posted February 25, 2012 Share Posted February 25, 2012 I wouldn't use lock tight, the heat will def make them tighter from expanding the bolts. Quote Link to comment Share on other sites More sharing options...
rossman Posted February 25, 2012 Share Posted February 25, 2012 Locktite blue on the PP to flywheel bolts and red on the flywheel to crank bolts. I wouldn't use lock tight, the heat will def make them tighter from expanding the bolts. Please explain... Quote Link to comment Share on other sites More sharing options...
Leon Posted February 25, 2012 Share Posted February 25, 2012 I like Ross's suggestion. I would use Loctite blue at the very least. Quote Link to comment Share on other sites More sharing options...
Perfect240z Posted February 26, 2012 Share Posted February 26, 2012 Locktite blue on the PP to flywheel bolts and red on the flywheel to crank bolts. Please explain... Well this is what I got from a mechanical engineer, basically when I was taking the flywheel bolts off during a tear down the bolts were obviously tight. I so to remove them we used a torch not on the bolts but on the flywheel side to expand the metal to relieve tension so the bolts could come loose with an air ratchet. I figure if the heat from the engine could make the bolts so tight that you need to turn up tue air compressor to like 150psi for the ratchet and use a torch on the flywheel to expand the metal around the bolts, then why use locktight? I'm in no way a professional of any kind just to be clear lol. But I also didn't see any locktight(or different colored dried goo) on the bolts anyways when I took them off, so I assume it was torqued down from the factory since it was a stock motor that hadn't been touched. Quote Link to comment Share on other sites More sharing options...
rossman Posted February 26, 2012 Share Posted February 26, 2012 I don't see how heating the flywheel would relieve tension on the bolts. Heating the flywheel will cause it to expand in all directions thus increasing tension on the bolts. Heating up the flywheel caused it to move due to thermal expansion and break the corrosion layer between the parts thus reducing the torque required to remove the bolts. Try an impact wrench next time. It will remove the bolts in a matter of seconds. Locktite is a much better secondary locking feature than the pressure plate lock washers and nothing in the case of the flywheel bolts. Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted February 26, 2012 Share Posted February 26, 2012 (edited)  The heat you used probably softened the locktite that was already there.  They should not be so tight that you need a torch anyhow.  Rusty maybe? Edited February 26, 2012 by cygnusx1 Quote Link to comment Share on other sites More sharing options...
Perfect240z Posted February 26, 2012 Share Posted February 26, 2012 I don't see how heating the flywheel would relieve tension on the bolts. Heating the flywheel will cause it to expand in all directions thus increasing tension on the bolts. Heating up the flywheel caused it to move due to thermal expansion and break the corrosion layer between the parts thus reducing the torque required to remove the bolts. Try an impact wrench next time. It will remove the bolts in a matter of seconds. Locktite is a much better secondary locking feature than the pressure plate lock washers and nothing in the case of the flywheel bolts. Whoops I didn't mean to say expand, lol I just did what he told me to since that's what he learned in school. Oh yeah I was using an impact wrench not an air ratchet. They were rusty to hell as we'll lol. Quote Link to comment Share on other sites More sharing options...
Perfect240z Posted February 26, 2012 Share Posted February 26, 2012 I guess I'd go ahead and use blue to? What about green? Isn't that pretty light? Quote Link to comment Share on other sites More sharing options...
steve260z Posted February 26, 2012 Share Posted February 26, 2012 The "How to rebuild your Nissan/Datsun" book uses Locktite. Quote Link to comment Share on other sites More sharing options...
Perfect240z Posted February 26, 2012 Share Posted February 26, 2012 Lawyered lol Quote Link to comment Share on other sites More sharing options...
luseboy Posted February 26, 2012 Share Posted February 26, 2012 I'd say definitely use red on the flywheel bolts and blue on the pressure plate bolts. You wouldn't want to use green... that's like a penetrating thread locker to use after the bolt is tightened down. Also it's not really a very strong threadlocker. Honestly who cares if it takes a little more effort to take off the bolts, at least they won't be able to come out on their own resulting in you being about 2 feet shorter. Besides that, how often do you need to remove the flywheel? Not very often at all. Quote Link to comment Share on other sites More sharing options...
HowlerMonkey Posted February 26, 2012 Share Posted February 26, 2012 I don't see how heating the flywheel would relieve tension on the bolts. Heating the flywheel will cause it to expand in all directions thus increasing tension on the bolts. Heating up the flywheel caused it to move due to thermal expansion and break the corrosion layer between the parts thus reducing the torque required to remove the bolts. The bolts will get longer as they "expand". Quote Link to comment Share on other sites More sharing options...
rossman Posted February 27, 2012 Share Posted February 27, 2012 The bolts will get longer as they "expand". Read the post carefully. They heated the flywheel, not the bolts...on purpose. Obviously the bolts will also get hot and expand due to conduction but at a somewhat slower rate. It seems to me that if you want to relieve tension in the bolts "with heat" that you would heat them directly not by heating the flywheel and thus the bolts indirectly. Anyway, I think the consensus is that Locktite should be used on all the bolts. Quote Link to comment Share on other sites More sharing options...
ctc Posted February 27, 2012 Share Posted February 27, 2012 Locktite changes the torque setting when you install the bolts. How would you compensate for that? I would rather have "dry" bolts properly torqued. Quote Link to comment Share on other sites More sharing options...
rossman Posted February 27, 2012 Share Posted February 27, 2012 Locktite changes the torque setting when you install the bolts. How would you compensate for that? I would rather have "dry" bolts properly torqued. It lubricates the threads during torquing, which is a good thing assuming you adjust the torque to compensate. Quote Link to comment Share on other sites More sharing options...
luseboy Posted February 27, 2012 Share Posted February 27, 2012 I've never heard of loctite changing the torque setting... It may affect it in a dry application (letting loctite dry on the bolt before installation), but even then it will be such a minimal difference, and for something like this... I don't see it as being that incredibly important. It could be important with an internal engine bolt, but you don't want to use loctite in there, and even then, I don't think it's gonna be much of a difference. Use red loctite on the flywheel to crank bolts. Less swearing will be done when heating the bolt and applying extra force for removal than would be done when the flywheel flys off and cuts your legs off . Blue loctite makes sense on the pressure plate bolts since they need to be removed for every clutch change, and they aren't that big of a bolt anyways. Not to mention it's far less dangerous if the pressure plate comes off than if the flywheel does... Quote Link to comment Share on other sites More sharing options...
rossman Posted February 27, 2012 Share Posted February 27, 2012 Admittedly I am very conservative about this but I assume the FSM torques are for dry bolts. Anytime a lubricant is added to the threads then the torque should be lowered. Dry torque assumes a higher friction coefficient. If you torque a lubricated bolt to a dry torque spec then you risk over torquing the bolt. Quote Link to comment Share on other sites More sharing options...
HowlerMonkey Posted March 2, 2012 Share Posted March 2, 2012 (edited) I was referencing the "increasing tension on the bolts" which will not happen since you won't be heating the flywheel without also heating the bolts. Edited March 2, 2012 by HowlerMonkey Quote Link to comment Share on other sites More sharing options...
280zex Posted March 2, 2012 Share Posted March 2, 2012 Definately use lock tite!! I learned the hard way. I did not use any lock tite on my last flywheel and clutch install. I torqued all bolts to spec. This lasted about 5k miles, then things got loose. I lost the clutch, flywheel, rear main seal, front trans seal and bearings!!!! And yes I have all new hardware this time too, this cost me almost 2k to fix!! Quote Link to comment Share on other sites More sharing options...
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