My engine has had a vibration for the last few days that I thought was a miss. After trying 3 sets of plug wires, new cap, rotor, spark plugs, and resealing the intake, checking all rocker arms, and a compression test, I started thinking it wasn't a misfire. So I pulled the harmonic balancer and found this. This balancer is only about 2 months old, I had the replace the last one because the front key was not in, and it spun a little bit. What could have caused this?

Pic 1, this is how it looked when it came off

 

Pc 2, After pulling the broken pieces out

 

Pic 3

 

DAMN!!

 

Obviously, you need to get another balancer. When you do, take exact measurements of the bore and keyway, then compare them to the keyway and O.D. of the crank. You may have a problem with the crank snout.

 

How in the world did the key end up on the OUTSIDE of the balancer snout?!?!?

 

You might actually want to check the crank snout first. If you can't mic at least 1.247" of meat or more, you might be shopping for a crank, or at least machining. Got a photo of the nose?

 

Is/was that balancer NEW?I would also mic it.Maybe when your other balancer went,it tore the crank snout up a little

 

The crank snout looked fine, but i couldnt see all of it with the timing cover still on. I will pull the cover off tomorrow and take a pic of the crank snout. In the meantime, I have a nice paperweight... :P

 

Maybe not so nice if it chewed your crank up. If so, it may be possible to repair the crank with a sleeve, but it would still require machining for the repair. We'll keep our fingers crossed.

 

The key was pushed back out of the slot as the damper was pressed onto the crank.

When you get the next damper slide the key into the damper keyway. Check that it fits and doesn't hang up. Be sure that the key is seated into the crank slot. Tap on it with a -small- hammer to seat it straight and level.

It can sometimes be tricky to get the damper started. As you start the damper onto the crank double check that the slot on the damper is lined up with the key. Also check that the key is staying in place.

RBob.