okay, here is the deal, if that has a factory balancer on it its two piece even though it looks like one and sometimes the rubber/elastic type thingy between the two wears or dry rots, even if this happened the piece the pulley bolts to on the balancer is the piece that bolts to the crank, so if the balancer to crank bolt and crank pulley bolts are tight the key way or crank is FUC^ED so when you say you can spin the pulley by hand do you mean the outer piece of the balancer?? or the actual crank pulley?