I attempted to replace my tensioner pulley today. I was able to slide the belt off and remove the old pulley successfully. My problem has been installing the new one. For some reason unknown to me I cannot get the bolt to tighten into any threads when putting the new pulley on. I've tried tightening the bolt without the pulley as well and still nothing. It's as if there are no threads to screw it into. I don't know if something has fallen loose that I'm not aware of or if I'm doing something wrong. It should be so straight forward, but the bolt refuses to catch a hold of anything and tighten down. It just spins freely. Can anyone help.