Please help

[Hemiride]

My son has a built 433 hemi in his jeep grand Cherokee. It's all forged and is pro charged.
He's having a problem with the crank damper cracking along the keyway slot. This is the 2nd one since spring. Its an ATI damper. What could be causing this?

 

[motorhead]

Consulted my brother the engine-nerd and here are his thoughts:

ATI hub will be hardened and that is a thin wall. Looks like fatigue failure. I hear they pin the balancer to add a second key way.

 

[BULL]

Is there any damage to the crank surface that is allowing additional movement/motion of the balancer that is causing stress?

I've heard it said NOT to use Loctite on balancers as it causes them to be non-concentric, but this makes no sense to me, the Loctite doesn't cause any extra clearance, it only fills what is already there...


Food for thought

 

[16GoManGoHC2]

Have you contacted ATI about the issue? Looks like a fit-ment issue, too tight or too loose on the crank snout, also could be the key itself is too high. The last one I fitted they wanted a .0002” clearance. Are you mounting this yourself each time or is a shop doing it? I ask looking for answer on how the hubs are going on, slide right on, tight pull with damper bolt etc?
Harmonic balancer installation seems like an easy thing but it’s not sometimes. Some have a special installation tool to seat it with, some want you to warm the unit in air and the B&M one mounted on my 302 wanted to be heated in hot oil for x time (was 1989 when it was out on)
Call ATI first if not already tried.
You don’t want this, cost my buddy 12k for a complete new 5.0 engine

 

[Hemiride]

Replaced the damper today. Son ran it about 1/2 mile and the damper broke.

 

[Hemiride]

 

[72 440 Barracuda]

How did the keyway measure up to the actual key? How did the dampner install? Tight with quite bit of force going together? Or go together loose? I am picturing an issue with the key and keyway relationship.

 

[Thawkmike]

Without seeing the installed setup, I’d say there is a massive belt alignment/tension issue with that procharger.


That happened within 1/2 mile? Something is yanking on that damper wrong.



Sent from my iPhone using Tapatalk

 

[Hemiride]

How did the keyway measure up to the actual key? How did the dampner install? Tight with quite bit of force going together? Or go together loose? I am picturing an issue with the key and keyway relationship.

The original key was too distorted to get an accurate measurement.
My son installed the damper so can't speak to how tight it was. But I think it was snug

 

[Hellcat Cuda]

I have a 6.1 stroker that was built by BES Racing, through HHP. The crank came with a key way and I provided an ATI damper to BES. BES honed the inside of the damper for a perfect fit. The key is also perfect height and width. When installing the damper, it slides on with some slight resistance, but no need to press with an installer, hammer of force with damper bolt.

It looks to me like your key is too tall. What method is your son using to install the damper and how much force is it taking?

 

[Hemiride]

As I thought about it, I feel the key is either too tall too wide or both.