This Maurey split pulley (I think that's what you call them) does not want to go back on the shaft. This is the main drive off the engine that runs the blades and the hydraulic system with the double belt. (Kawaski 27 hp Scag Cougar with 52" deck, '02 vintage. It kind of looks like the pulley insert is threaded where it goes on the pulley, although why would they do that? The insert that has the hole for the shaft does not want to come off the pulley. The insert is split, and the information I got about these says you have to take out the insert put the pulley on, then put something in the split so it widens, so you can get the insert on the shaft, then bolt on the pulley. We put penetrating oil and soaked the pulley good, and still stuck.