OlderThanMe Posted July 29, 2007 Share Posted July 29, 2007 Hey All... I am running an 11lb SPEC flywheel. I installed the flywheel back in early May and torqued the bolts in stages in a criss-cross pattern just like the haynes book says. I also used Loctite Red threadlocker. I have about 200 miles on the motor since putting it all together and I am hearing the flywheel rattling at idle. I drove the car for about 25 miles with some 2-6k RPM pulls. Nothing crazy. When I got home I noticed a rattling noise. I thought I hadn't tightened a rocker arm down hard enough but it wasn't that. The sound was coming from the bellhousing. At this point I am just going to pull everything out and part out the motor. I'm just wondering what caused this??? Are the bolts just old and loosening because of that? Quote Link to comment Share on other sites More sharing options...
veritech-z Posted July 29, 2007 Share Posted July 29, 2007 I've seen a Fidanza SR20DE flywheel do that also, supposedly it's normal but nobody could tell me what it was. It was really bad on startup in my friend's car. My Jim Wolf flywheel/clutch setup on my 02 Altima doesn't do it though. I'd pull the tranny and check the bolts. Maybe you broke a fork off of your pressure plate? Quote Link to comment Share on other sites More sharing options...
bubbleguinea Posted July 29, 2007 Share Posted July 29, 2007 did the bolts actually go all the way in? by saying this, i mean that if the surface where the bolts go on the flywheel is say, thinner, than stock, then the bolts would bottom out inside the crank, thus not get torqued properly... there was a write up somewhere on either this site or zcar.com, i cant remember.... Quote Link to comment Share on other sites More sharing options...
Sparks280zt Posted July 29, 2007 Share Posted July 29, 2007 DragonFly covered this issue in some of his posts. Maybe PM him about it. Quote Link to comment Share on other sites More sharing options...
datman Posted July 29, 2007 Share Posted July 29, 2007 I've just fitted the same flywheel, It was a very tight fit on the end of the crank. I can't imagine the bolts wouldl come loose, especially if red loctite was used. Let us know what you find. What type of clutch kit did you fit? Quote Link to comment Share on other sites More sharing options...
Sparks280zt Posted July 29, 2007 Share Posted July 29, 2007 http://forums.hybridz.org/showthread.php?t=123299 post #5 Quote Link to comment Share on other sites More sharing options...
TimZ Posted July 29, 2007 Share Posted July 29, 2007 http://forums.hybridz.org/showthread.php?t=123299 post #5 That post is talking about the bolts that fasten the pressure plate to the flywheel - is that what we are talking about here, or are we talking about the bolts that fasten the flywheel to the crank? Quote Link to comment Share on other sites More sharing options...
NCchris Posted July 29, 2007 Share Posted July 29, 2007 That post is talking about the bolts that fasten the pressure plate to the flywheel - is that what we are talking about here, or are we talking about the bolts that fasten the flywheel to the crank? Seems to me from the description so far, it could be either. OTM said his noise was coming from the bellhousing. You do not want either the pressure plate or flywheel coming loose! chris Quote Link to comment Share on other sites More sharing options...
bubbleguinea Posted July 29, 2007 Share Posted July 29, 2007 sparks, thats what i was talking about- thanks! Quote Link to comment Share on other sites More sharing options...
TimZ Posted July 29, 2007 Share Posted July 29, 2007 sparks, thats what i was talking about- thanks! This was my point in mentioning that the quoted post is talking about pressure plate bolts - NOT the flywheel-crank bolts. I don't believe that there is any issue with the flywheel-crank bolts being too long. Seems like I've seen this get confused several times. Quote Link to comment Share on other sites More sharing options...
Dragonfly Posted July 29, 2007 Share Posted July 29, 2007 This was my point in mentioning that the quoted post is talking about pressure plate bolts - NOT the flywheel-crank bolts. I don't believe that there is any issue with the flywheel-crank bolts being too long. Seems like I've seen this get confused several times. Datsunan had a problem with his flywheel bolts but is was because he left the spacer from a flex plate on the back of the crank which would not cause what OTM is talking about... but it makes me wonder if in the past longer bolts may have been used on his car then the spacer removed when the new flywheel was installed while re-using the longer bolts??? Just a theory. Dragonfly Quote Link to comment Share on other sites More sharing options...
TimZ Posted July 29, 2007 Share Posted July 29, 2007 Datsunan had a problem with his flywheel bolts but is was because he left the spacer from a flex plate on the back of the crank which would not cause what OTM is talking about... but it makes me wonder if in the past longer bolts may have been used on his car then the spacer removed when the new flywheel was installed while re-using the longer bolts??? Just a theory. Dragonfly As far as I know, there are no flywheel bolts of this size and thread pitch that are available in a longer size. You could probably go and find something at the hardware store, but that would most likely not be an appropriate bolt for this purpose. this did get me thinking, though. OTM - do you notice this sound all of the time, or just when the clutch is disengaged? If it's just when it is disengaged, then it could be the same problem that Datsunan posted about... http://forums.hybridz.org/showthread.php?t=120974 Quote Link to comment Share on other sites More sharing options...
OlderThanMe Posted July 29, 2007 Author Share Posted July 29, 2007 Thanks for the replies guys! I had this happen the first time I had this flywheel on the car. I then pulled it back apart and mounted it properly to the crank with the criss-cross torqueing and loctite. I ran it the first time about 750 miles before it came loose. This time I have about 80 miles on it and I hear the slight knocking at idle. I am using the spec stage 2+ 225mm clutch with this setup. I know the engine (L26) was rebuilt in the late 80's with some L24 flattop pistons and that was about it. The flywheel was an original heavy flywheel. All I did was replace the flywheel/clutch kit with the Spec stuff. That is $800 of stuff in my tranny right now... One of the 225mm PP to flywheel threads stripped the first 2 threads out of the flywheel and I just put extra loctite on that. The threads for the PP go all the way through the flywheel FWIW. The clutch is way awesome as it grabs well and does not shutter at all. It is a full organic sprung disc with the stage 3 PP. (making it a stage 2+ AFAIK) Perfect clutch for a way more powerful N/A motor as it is rated to 260 horsepower. (I'm lucky if I am making 140 at the flywheel at 9.2:1) I did not have this problem on initial startup as I listened for the noise before driving it any. I want to know what this was before I start doing my VH45. Would wiring the heads of the bolts work to keep them from backing out? I figured I'd blow this motor up but not this soon... I want learn how to get this right before building an expensive motor. Thanks! OTM Quote Link to comment Share on other sites More sharing options...
Dragonfly Posted July 30, 2007 Share Posted July 30, 2007 As long as you are able to properly drill each of the bolts for lock wire then you can lock wire them and know for sure they are not going to back out. If you do that make sure to use a high quality lock wire and not any of that crap that you find at Harbor Freight or similar establishments. Since this appears to be a reoccuring problem (has happened at least once before) I have to ask, did you replace the bolts? If you did replace them then I would suspect there is something possibly wrong with the crankshaft or flywheel. You could take out the flywheel and take it to a machine shop to have it wet magged to make sure there are no 'invisible' cracks around the bolt holes causing the flywheel to flex under load. Dragonfly Quote Link to comment Share on other sites More sharing options...
OlderThanMe Posted July 30, 2007 Author Share Posted July 30, 2007 That is the problem. I did not have time to order new bolts before I was supposed to have the car running to go to Zdayz. I went from longblock on stand to motor installed in car and almost running back to shortblock in car, then fixed head and back to a running motor all in 5 days. I didn't have time to order new bolts. I am thinking that the flywheel bolts are the only real variable since the crank's threads are fine. This brings the lesson: Don't rush a project and not do it right. Oh well. Quote Link to comment Share on other sites More sharing options...
spacecase70 Posted July 30, 2007 Share Posted July 30, 2007 Here, HERE!! Quote Link to comment Share on other sites More sharing options...
TimZ Posted July 30, 2007 Share Posted July 30, 2007 I am thinking that the flywheel bolts are the only real variable since the crank's threads are fine. Are they actual flywheel bolts, or are they just bolts that happened to fit? I don't believe that the actual flywheel bolts are "strectch-able" - if they aren't pitted or visibly damaged they should be fine. You might want to check for hairline cracks in the crank at the crank threads. Quote Link to comment Share on other sites More sharing options...
Evan Purple240zt Posted July 30, 2007 Share Posted July 30, 2007 I never replaced my flywheel bolts either on my L motors or my RB. No problems yet. hairline cracks sound like a possibility you should check into. Evan Quote Link to comment Share on other sites More sharing options...
Noddle Posted July 30, 2007 Share Posted July 30, 2007 I had this problem with my 6 cylinder Ford 250 Xflow engine in my XK falcon, the bolts would loosen, replace the bolts, put it back together, give it a good rev, same thing, very frustrating, in the end, the problem was the flywheel, the holes where ever so slightly out of round, replaced the fly wheel and all was good.. Nigel Quote Link to comment Share on other sites More sharing options...
Clifton Posted July 31, 2007 Share Posted July 31, 2007 I had this happen on an L28. I wasn't running a damped pulley though. It trashed the crank and flywheel. I had it happen on my 7m too. On this the crank pulley also came loose and I think that led to the flywheel problem. I was revving it 1k higher than stock (7600), might be the reason?. It ruined the crank, flywheel, and crank pulley. When I removed the flywheel, the bolts were tight but the flywheel wobbled on there enough to create high and low spots, from the heat. I always use locktight red too. I had used an impact on these to install. When I put it back together I checked to see what I was really torquing them to. Around 30lbs tighter than they should be, so they were definitely tight enough. I droped my rev limiter to 7200, I hope it solve my problems. Quote Link to comment Share on other sites More sharing options...
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