fan clutch removal

I'm trying to replace the water pump on my jeep, I have the 6 cylinder 4.0. I have the shroud off,belt,power steering bracket. I've been told there is a drive nut between the fan and pulley but my jeep does not have this drive nut. I have removed the 4 nuts that the fan assembly attaches to pulley and the 4 bolts that attach the fan blade to the fan clutch. I still can't get the fan to come off. Is there something else I'm missing, I used a rubber mallet to try to pound the fan off and that hasn't worked. Any tips or advice would be greatly appreciated.