1996 belt is eating away - bad dampener?
 

Hello I had to replace my belt tensioner and I replaced the belt. I noticed the belt was much wider than the old belt. The old belt is a dayco and the new one is a green gates.

As soon as we got it on right and started it up it came off track on the fan pulley. We adjusted it and tried it again and it came off after a few start/stops of the engine.

I noticed the harmonic balancer/dampener is wobbling. The actual pulley part where the belt goes is wobbling as well as the entire thing. I'm assuming this is what's causing the belt to come off track on the fan pulley?

Would replacing the dampener be the fix or is this a more serious internal issue (crys!)?

Any tests for the dampener or things to look for that would lead to the dampener itself being bad?

The truck has the mods in my signature and has 280K miles on it.

you should always replace the damper, thats a $9000 engine if you grenade it and had to buy some reman at cost. dampers dry out from factory easily in 10-15 years depending where in the world you live. get an ati or fluidamper asap. people are always quick to jump on making power but dont realize the important parts that keep the truck together. as for it wobbling, sounds sketchy. take the old one off, get a fluidamper, check out the crank shaft snout when its off. you would likely know if your crank was messed up, but definltly replace the stocker