Thanks for your reply. The pulley wasn't turning when the drive was engaged so I removed it and put it back on, but didn't tighten it so much that it wouldn't turn. It seemed like a strange set up... the bolt was fully threaded and the bushing was between the pulley and the bracket. The bushing wouldn't go into the center of the pulley??? I would have thought the bolt would be a shoulder bolt going through the bushing inside the pulley. Does anyone know where I can find a parts diagram for my Ariens self propelled mower?