I'm getting there as far as tearing the 79 cx500 down, but after removing the radiator and themstat and assorted hoses and pipes, I unscrewed the fan bolt and notice the fan is loose on the metal collar in the middle, as if it got worn out. However, i can't seem to get the collar (for lack of a better term) to budge so I can remove the fan. I'm tearing down the motor to determine why the valves aren't moving when I manually turn the crank. Any suggestions?