I suppose the electro magnet (I didn't know what it was called). Not the supercharger pulley. With the engine off and the belt on the pulley, so it doesn't spin by hand, this is the part behind the pulley that will spin by hand. I can spin it clockwise or counter clockwise probably a 1/16" before I feel it hit and start to spin the gears. There is no bearing noise at idle.

I was just wondering if this is normal or if others have zero play.