2 days ago my old serpentine belt jumped off going home. it damaged the belt so i got a new one. installed the new one today fired the truck up i hear it jump off again then shut it down and i find that the crank pulley is loose. i retighten it reinstall the beltand the f-ing belt jumps off again and i cant hear the pulley spinning after i shut it down again. what do i need to do? can i use locktite on the bolt? how much torque does the pulley need? please help.