Greg, I've acually seen a video on this. It had a guy on the line with a fare sized hammer. As the pulley spun he'd hold the hammer next to the pulley to determine where it needed to be hit, get his timing down and he'd smack that pulley. only had to do it a couple times and it came out pretty good. Good luck, if you get a chance have somebody do a video. The video I saw was on a combine Walker drive. I tried it on the big pulley on an electric cement mixer years ago and it didnt go so well.