Help: Bad Harmonic Balancer

[408.Luke]

OK 2500HeavyDuty called me today at work and was crying about this.
[YOUTUBE]PK3PXadVCRs[/YOUTUBE]

He's kinda worried the crank is bent, but i highly doubt it. He said on Friday he was on his way home from school and it started knocking (he wasn't driving hard) popped the hood and found this, he replaced the tty crank bold (but didn't know if he got it tight enough) i seriously think its just a bad balancer but i think he is looking for an excuse to build his motor If he dosent get this fixed soon he will end up having to drive my truck which isnt a big deal but anyway anyone ever seen this before or have a better idea than me?

 

[JoshH]

I would pull the balancer off and see how much if any play you have in the crank snout.

 

[Mike]

I would pull the balancer off and see how much if any play you have in the crank snout.

Could he do that with the balancer in place and the bolt out? He would then be able to watch to see if he spun the balancer on the snout and check the crank play. If it's knocking, not a good sign.

 

[408.Luke]

He said when he replaced the bolt he removed the balancer and tried to wiggle the crank, and was to afraid to run the motor with out the balancer. I dont think he has a way to check run out on the snout untill i get back from laredo and as far a spinning the balancer he said when he pulled it off the snout looked fine but that the front main seal was bent back towards the motor on the top 1/2, so that had me worried. The knocking is coming from the front of the motor but cant tell if its the balancer or the motor

 

[Rhall]

Looks exactly like mine when the crank broke. Like i told him, the only reason i knew was because it threw the belt twice, it made no noise what so ever, and ran fine. It even ran a 7.2 the the 1/8th mile on one cp3 after it threw the belt, the crank was obviously already broke, i put the belt back on and made another low 7 second pass, and it threw the belt again, then decided something was definatly wrong, so we ran it without the belt, and thats when we noticed the balancer.

 

[wdino73]

That looks an sounds just like mine when the snout was broke, right inside the first counterwieght. Sorry Good Luck

 

[408.Luke]

Wow so this seems like a somewhat common problem, does any one know what would cause a broken crank? out of balance? turned too many rpms? its hard to think that a stock turbo truck could do this

 

[wdino73]

I can't answer that, I wish I could, but I do know why mine broke, but that has nothing to do with this one, He needs to get the balancer off before we can fully agree it's a crank problem.

 

[Rhall]

Ive heard of a few stock turbod trucks breaking, mine was just up in that horsepower range i guess. Hopefully thats one of the next thing we figure out as dmax hotrodders, how to make the crank last.

 

[TrentNell]

Ive heard of a few stock turbod trucks breaking, mine was just up in that horsepower range i guess. Hopefully thats one of the next thing we figure out as dmax hotrodders, how to make the crank last.

Sadly Rob I think the answer is a better crank , I know 1Badmax ( Jay) is trying some stuff in his motor now that may be beneficial to the rest of us. I dont think the balancer can move that much any other way than a broken crank , sorry to hear man and i hope we are wrong for your sake

 

[Rhall]

Sadly Rob I think the answer is a better crank , I know 1Badmax ( Jay) is trying some stuff in his motor now that may be beneficial to the rest of us. I dont think the balancer can move that much any other way than a broken crank , sorry to hear man and i hope we are wrong for your sake

I know, ive heard of some options coming up, but who knows if they will work.

 

[408.Luke]

Sadly Rob I think the answer is a better crank , I know 1Badmax ( Jay) is trying some stuff in his motor now that may be beneficial to the rest of us. I dont think the balancer can move that much any other way than a broken crank , sorry to hear man and i hope we are wrong for your sake

yeah i hadent seen the vid when i first talked to him and then i saw and was just trying to be hopeful lol. Never realized cranks were such a problem use to ls1's where stock cranks see over 1,000 hp without any problems. We'll get the balancer off and see what it does.

 

[2500HeavyDuty]

crying?? nice luke :rofl:

it looks pretty bad from where im at, i think i have some pics of my front main seal on my phone of how the crank looks ill get them uploaded when my phone comes back alive.

the knock sounds hideous, when i first was chasing down the noise i seen the balancer thrusting backward and forward on the crankshaft bouncing inbewtewteen the fan and font main seal, so i though maybe the bolt had come undone.

but when we got to pulling the balancer off the bolt was still as tight as we left it when i did my water pump. the balancer looks fine we cant get it to wiggle when its off the truck, but when we install it and tighten the bolt down we can wiggle the whole front of the crank

 

[2500HeavyDuty]

one thing i can add is when i took the balancer off and threaded in the bolt in all the way it could wiggle the bolt around, or i at least i hope it was the bolt i was wiggling

 

[408.Luke]

Time to get the engine hoist out of storage.... again dang i think its only been in there two weeks lol we cant keep anything running, and got to get the trans jack to pull my ally boy are we gona be busy! :banging:

 

[2500HeavyDuty]

hell yeah :thumb:

 

[Mike]

Good luck Danny, I hate to have to second the seconds and thirds on the crank. Good luck and hope you get it up and going again soon. :thumb:

 

[2500HeavyDuty]

well, im getting ready to pull out the motor, anybody want to buy some ranch hands

 

[2500HeavyDuty]

btw, thanks guys. this will be a good, but painful experience

 

[wdino73]

Here's the way mine broke,