i just finished a 396 lt1 and the crank is a callies dragonslayer with lunati pro mod i beam with srp pistons the crank is neutral balanced and the flywheel and clutch assembly were also neutral balanced from spec. its a stage 3+ the balancer is neutral balanced out of the box .but for som reason my balancer keeps comming loose. so far ati is the only company to step up and asked me to send them the balancer for them to check. if it comes back ok i guess the next step would be to remove to clutch assembly and have it checked from another place other then spec. if it checks out ok the i guess my next concern would be the crank which i dread if it has to be pulled. has anybody ever had this problem before and what steps would you take to figure this out. thanks abunch for your help.

 

It is held on by the balancer bolt. How do you mean that it's coming off?

Rich

 

Is the HUB backing off the crank snout?
(held on by 1 bolt with a BIG washer... 7/16"-20 thread pitch I belive...about 3" long... should be 60+ ft pounds I belive)

Or is the actual damper assembly loose on the hub?
(6 torx-headed bolts, and 3 larger 12-point bolts on mine, but I'm using a BBC chevy OD, LT1 ID hub so there may be some extra bolts on mine... I know some ATI dampeners come with even MORE bolts as well... but it should be 6 to 12 bolts between the hub and dampener and only ~20ft pounds if that... check the instructions).

These are two very different things. Sounds like you mean the first one.

Did the Callies crank snout come with a woodruff key machined into it? If so, make sure the key is in there... that will stop it from spinning if the bolt gets loose (stock LT1's didn't use any key but I belive ATI has a keyway in all of them... or 2 if youre crazy like that ). I'd be suprised if Callies didn't have one machined in from the factory...though I'm not sure if they'd put the key in automatically for you (it may be in a pouch that came with the crank.

BTW, if the bolt is backing out you may want to get an ARP bolt... their threads are excellent and should mate well with the crank threading. My $6 Mr.Gasket bolt we used for the initial build went plastic when tightening it down. There's a LOT of force on that bolt, pay $20 for the ARP bolt if you think the hub may not have all the interferance fit it should have.

BTW... do you have an ALUMINUM hub? I've literally slid one ATI aluminum hub onto an LS1 with no heat, impact wrench or even socket... it just slid on. Scarey whay can happen after a few remove/install cycles with aluminum hubs. I'd stick with steel hubs if you're having problems. Just a thought.

 

BTW, put a mic on the ID of the hub, and on the OD of the crank snout (at the same temperature of course).

What's your measured interferance fit?

 

the hub is steel and the hub assembly is sliding forward i have an arp bolt and washer and the is a keyway came on the crank but you can remove it , it fits perfect on the hub i torqued the bolt to 75 ftlbs and also made sure the bolt did not bottom before it was all the way on. also the hub has to be pressed on with alittle anti siege. but the bolt comes loose and then the balancer moves forward. thanks for all your help.

 

What year is your engine..... i.e. - does it have/did it have a crank position sensor? If it does not/did not you may need to install the spacer that comes with the ATI.

Might want to add a "signature", with basic info about your car.... year, model, engine, tranny and any major mods. That way people can help you better.

 

Mine came with a big washer to go inside the hub also.

The ATI are supposed to be honed to fit when new....was it honed?

 

yes i put the spacer that came with it on it is a 95. and the balancer was new the guy at ati just wanted to make sure the balancer did not just slide on. it was a tight press but not abnormal.

 

Sounds fine. Do you know how much interferance fit you have?

If you take it off again, do NOT use anti-seize... this defeats the purpose of an interferance fit. Clean it off and use a torch to heat the hub before installing (all you need is to get it on far enough to line up the keyway, then crank it down with a wrench... if it stops short you'll probably need an impact gun to get the last 1/4" or so).

Still... even with antiseize it's strange the bolt is backing out. If the crank and hub are keyed it shouldn't turn anyway.

Unfortunately it sounds like your crank snout threading may be too large to get a tight fit. If it were any other location I say just lock-tite it or helicoil it, but on a crank snout I don't know if that's such a hot idea.

talk to a local machinist and see what he suggests. Definately a strange one here.

 

the machinist that did the block does not have any answers ive called everybody and no one has any idea. i only put a little anti-seize on the inside of the hub and loctite on the bolt and it still loosens up .the hub does not spin on the crank so i have no idea whats the problem the only think that comes to mind is somthing is out of balance cousing a vibration but the engine runs great and very smooth even with the cam 240/240 duration and 595 in and 595 ex lift.

 

It seems ths LSx engines also have this problem after repeated removal/installs: http://www.z06vette.com/forums/f5/ha...-engine-68418/

But in that case the bolt has larger thread pitch and isn't key'd at all... just spiked (if it's done right). If you've ever seen it, the LS1 "miracle bolt" is much larger though and they torwu those suckers to 250+ ft pounds. (contrary to the text of the link above though, the new GM LSx bolts I recently saw DO have a red compound on the threads, not sure if this is new from 2005 or if they were mistaken).

Anyway, it appears that red locktight isn't such a bad idea. I'd probably shoot some brake cleaner in the hole to clean out any dirt or oil that may be in there (either giving a premature 75 ft pounds or lubricating it later to allow it to back out). Air gun to dry it out and red locktite it. One poster above mentioned his bolt couldn't back out all the way because something was in front of it... might be an option to put a bracket 1/2" forward of the balancer while you're checking it out (not much of a solution I know ).

Still... this doesn't seem to be a ATI issue... if it has an interferenace fit, slides on as deep as it should, and runs smooth I gotta belive it's a problem with the threads either in the crank snout or on the ARP bolt. I'm partial to the crank, but clean it out and locktite it before freaking out.... could be there's still some machinist oil in the crank snout libricating the bolt. Clean them both with brake cleaner and try again.

keep us posted!

 

It appears this is even more common on blower applications since they use a spacer between the hub and the crank sprocket (much like OBD-I LT1's), but for blowers they use THREE spacers. http://www.ls1tech.com/forums/showthread.php?t=38457

Their spacers were deforming under pressure (remember, those LSx guys may have a WIDE bolt head, but they torque it to 250 ft pounds!).... so the fix was to cut the bolt down and use one hardened washer.

I don't know if that's the cause of your problem though since the ARP washer is usually VERY thick and strong for SBC/LT1 applications.... although the spacer ATI provided may be compressing, worth checking I guess.

Somewhere you simply arn't getting the clamping force you need. deformed spacers? grit in the threads? lube on the threads? weak/thin thread engaugement? could be a number of things.

 

i dont know if our problems are in any way the same but the other day i found my hub bolt loose as well, stock crank and balancer, i took the balancer off and left the hub in place, put some red loctite on the bolt and used a large pair of water pump pliers/channel locks to hold the hub and got it really tight with a 1/2 inch ratchet. just be carefull to not pull the threads out of the crank. i have not had any more issues as of yet

good luck with it

 

the link thar was givin to me had the only idea i have not tried . locktite and a lock washer did not work either. im hopeing the bolt may be a little long and not be fully seated for proper torque. ill keep you posted. thank again.

 

I did notice the ARP bolt is a bit longer than the Mr. Gasket crap I was using, but it wasn't enough to bottom out on my Compstar crank. Could be your crank threads are a bit shallow.

Before you "modify" your expensive ARP bolt, you may want to use a depth gauge (screwdriver ) to check the bolt hole.