If you have the belt off & you twist the pully in a forward and reverse moition really fast, should it be tight. mine feel like its on a rubber band, its "springy". Is it about to go out?
If your turning the pulley, and there is ANY play in it, or it knocks, your nose cone is bad. They sell a rebuild kit for it so you dont habe to spend 2 grand on a new s/c. hope that helps.