I changed my timing belt and belt tensioner a week ago and all went well,untill lastnight.When I heard a thumping sound and found my crank pully bolt was loose again.Itook everything back apart in the dark during a ice storm and now I think I have a major problem.The pin that locates the pully is sheared off flush with the outer plate of the timing belt sprocket.is there any cheap way to fix this?,do I have to replace the belt sprocket,if so how hard is it to get off ? how expensive will this be ? Can I line the pully and gear up on a drill press drill a hole through both pcs. And drive a pin in ?