...I have search and searched and search and cannot for the life of me find a replacement pulley. The bearing has brinelling and has been making a loud clacky clack noise as it turns. I took it apart and crammed it full of grease which has helped quiet it down, but it still needs to be replaced. Packed full of bearing grease it just makes a "click" noise, sort of like the noise a bicycle makes when you arent peddling.

 

You don't need to replace the whole pulley. Just change the bearing out. I used one of these for my A/C idler: 6203-2RS Bearing 17x40x12 Sealed Ball Bearings:17mm