I'm replacing the belts on my 89 62 and am having problems w the first or ac belt (closest to the engine). I'm not sure if I got the right belt. The tensioner seems to top out before the belt is tight. I turn the tensioner and the belt gets tighter and tighter, but before it tightens the acorn nut on top of the bolt pops off. I'm thinking the belt is too long so the idler is going to it's max and then starts to loosen the acorn nut. Does this make sense?