rushr

So today as I was pulling through the gate at the base I heard a loud knocking/banging noise coming from the left side of the motor. I couldn't hear it inside the car at all except with the windows down and as I drove by buildings. So I get out and check to see what it is and notice that the belt from the crankshaft pulley to the power steering pump looked kind loose...loose enough that I managed to get it off without much effort. I thought maybe the noise was the belt hitting something, but it wasn't. Upon further inspection I noticed that the crankshaft pulley was loose and wobbling. I left the car there and after work went home to get my tools. The crankshaft pulley bolt was loose so I tightened it back down and the pulley was solid again. Started up the car and within a minute is was clattering again and the pulley was loose. I tightened it up again about as tight as I was able to at the time started it up again...everything sounded normal. I left it run while I put my tools up and made sure everything was picked up. I drove it a couple blocks and the noise came back...so I parked it and what would you know...the pulley bolt is loose again.

Does anyone have any ideas why it would all of a sudden come loose and now won't stay tight? Is there something I need to replace or any type of a loc-tite that I need to put on it or what?

Thanks for any help.