crank pulley?? please help

[white 2g awd]

allright, wife said her galant was making a rattling noise, i went out and looked, crank-ps-a/c belt was off, so i took it out, started it up real quick and the crank pulley that this belt attaches to was shaking more than beyonce's ass....is there any chance that its just the crank pulley????? this is a 99 galant with the 4g64 motor. i'm really hoping it didn't screw up the crank or anything since this is a weak 7 bolt....and this is her daily driver, she has to have this car to go to work, i'm having it towed to mitsu now, but they can't look at it for about a week. any ideas??? thanks.