here's the part:
it's part #4 on this diagram:
Hopefully this pics worked, thanks-
That is an idler pulley.
Take the idler pulley off and take it with you to Tractor Supply if you have one close and see if they have anything that looks like it . Graingers is also a good source. If all else fails, local John Deere dealer can either provide or order.
thanks guys, found a replacement.