pulley is seated and the bolt torqued properly. A loose crank pulley can destroy the crankshaft, which means you'll need a new engine. There is obviously something wrong with your installation procedure. Kong has given you good advice. I say: take it off, look it over for any damage, before doing a proper installation. When seated the pulley will extend past the end of the crankshaft by a miniscule amount, (sorry I don't have the number, maybe .020). It's just enough to ensure that the bolt is seating on it, and not the crankshaft. Make absolutely sure that the bolt is torqued properly. Make absolutely sure that the bolt is torqued properly