While mowing today the crank wheel came off the drive shaft. The key was lost, so don;t know if it was damaged and was the cause or not.Haven;t torn the mower down yet, but can't find what broke off pr came loose to allow the wheel to move. Question-- what holds the wheel to the shaft? Does the key fit tight enough to hold everything in place? It does not appear that anything broke off the end of the shaft--ie-- a threaded portion and a nut. I've mowed with these mowers for years, but other than greasing the Pittman, I never paid much attention to how the wheel is attached. Any information or advise about how to repair the mower would be appreciated. Thank you. Dr. Bert Email is open.