Huh?? 
LS2 balancer keeps slipping on stock car
LS2 balancer keeps slipping on stock car Ive been a life long hemi guy, so never messed with the LS stuff before until now. Picked up this clean C6 for cheap and have been trying to enjoy it and mess with something diffrent. A couple days after i got it, i had a bad belt squeak, replaced the belt and noticed the bolt for the harmonic balancer was loose. And balancer was half way worked off the crank. Pulled the rack and replaced it with a dorman unit and some red Loctite on the bolt, sent it home with the milwauke impact. That apparently was not enough, 2 days later its loose again. Ran the old bolt back on tight. Removed it, threw it away, replaced it with a GM bolt and some lock tight. Held the engine still by the converter with a metal bar i fabbed up real quick and gave it the beans with a long breaker bar, Thing is stupid tight now. Fast forwar a week, bolts tight, balancer spins on crank now. Im sure the crank is jacked, im sure the new balancer was jacked when it came loose again. Was hoping i would get lucky. So now i need to fix it for good and not stress about it breaking down every time i drive 20 mins to work. That being said, whats the go to balancer? and the go to kit to pin it? Not really wanting to spend the ATI money on it was looking at powerbond units. They have a keyway already, but its squared off. Can i run this unit and just pin it on either side away from the existing keyway and get away with this and be ok? or am i wasting my time. Ive never seen a balancer do this on a car thats not driving a supercharger before, the hemis you can just run em on there and they are good for life so im learning here.
It is atleast that tight. The bolts tight, but i suspect there is some damage to the crank snout more than i noticed not allowing it to hold. So i plan to pin it if that will suffice.
Im just not sure the best route to go.
Im just not sure the best route to go.
The stock style/Dorman balancers are good to pin. I usually only switch to an aftermarket if I have an aftermarket crank with keyway. You can put a round pin in a square keyway, and another on the other side, I just found it hard to drill. The drill would slip towards the key slot on the balancer and not drill into the crank as much.
I've never seen the bolt come loose like that. The OEM style bolts have that red locktite-ish stuff on the underside of the flange.
I've never seen the bolt come loose like that. The OEM style bolts have that red locktite-ish stuff on the underside of the flange.
TECH Fanatic
Joined: Jan 2009
Posts: 1,067
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From: Bostwick, GA.
It comes loose as the interference fit of the balancer is gone.
The balancer dances around on the crank and the bolt comes loose.
Pinning a loose balancer on a trashed crank isn't going to work, either.
The balancer dances around on the crank and the bolt comes loose.
Pinning a loose balancer on a trashed crank isn't going to work, either.
TECH Regular
Joined: Aug 2007
Posts: 405
Likes: 42
I would pull the balancer and mic the crank snout. That’ll determine if it’s a trashed crank snout or if the balance ID is wrong. Dorman makes decent OE parts but there is still a good chance it could be out of spec..
quick google search and it looks like the snout should be 1.484” diameter.. I’d check it.. also check the ID of the balancer you have and see if it’s larger than 1.484”.
quick google search and it looks like the snout should be 1.484” diameter.. I’d check it.. also check the ID of the balancer you have and see if it’s larger than 1.484”.
TECH Fanatic
Joined: Sep 2008
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Just a thought.
Before you pull the engine. Torque the balancer to spec and then put a dial indicator on the balancer to check for run out. I don't know the spec (if there is one) for runout but it has to be close to zero.
If you have some level of run out the crank snout is toast?
If no run out I would drill all the way thru the balancer and crank snout vertically and pin it with a harden split roll pin. What do you got to lose? I'm guessing you would need to pull the front cover to get room to drill. It would mean you would have to drill thru the balancer bolt so maybe a 1/8" split roll pin?
One more bubba fix. Drill and tap the balancer snout vertically maybe 1/4" fine thread and then drill into the crank snout a ways for a hardened set screw?
Ok one more really bubba fix. Assuming no run out torque the balancer bolt to spec and the tack weld the bolt to the balancer?
Before you pull the engine. Torque the balancer to spec and then put a dial indicator on the balancer to check for run out. I don't know the spec (if there is one) for runout but it has to be close to zero.
If you have some level of run out the crank snout is toast?
If no run out I would drill all the way thru the balancer and crank snout vertically and pin it with a harden split roll pin. What do you got to lose? I'm guessing you would need to pull the front cover to get room to drill. It would mean you would have to drill thru the balancer bolt so maybe a 1/8" split roll pin?
One more bubba fix. Drill and tap the balancer snout vertically maybe 1/4" fine thread and then drill into the crank snout a ways for a hardened set screw?
Ok one more really bubba fix. Assuming no run out torque the balancer bolt to spec and the tack weld the bolt to the balancer?
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From: Halfway back on the Highway to Hell...again!
ok, You need to pin or keyway the crank and balancer. I've seen this a million times. The balancer is spinning on the crank. No normal amount of torque is gonna hold it. IMHO, the crank bolt should be LH thread, Once it spins a time or two, the tolerance is gone. Not a big deal. If it's a stock crank and stocky style balancer, just get the pin kit and pin it.
Granted, it will not be a FUN job on a C6. But it is what it is.
Granted, it will not be a FUN job on a C6. But it is what it is.