I have a '14 GT with a 2.3L Whipple Supercharger with a 3.00 pulley on it. At the end of last summer, my serpentine belt went bad and began to fray. I had it replaced with a Dayco belt # 5060820 (Gates K060820). I stored the car all winter and when I started it, there was a ticking sound from under the hood. I checked it and the serpentine belt had moved back (toward the supercharger) one rib. It then jumped back to the normal position on the pulley. It happened again the other day, same situation but now the new belt that has less than 10 MILES on it, is showing wear along the rear edge. Any ideas?

 

You have a loose/worn idler/tensioner pulley or one of your pulleys is out of alignment. The fact it's jumping back and forth makes me look more at a worn bearing in the idler or tensioner pulley or loosely mounted one.