[Herb Concord Ca]

Dirttrack, in looking at your pictures, you have a metal fan, I run a plastic fan and the collar won't fit under the fan hub.
In your case, remove the pump, remove the fan, loosen the brass packing nut and slide the shaft out the back of the pump far enough to remove the collar. Reinstall the shaft, install teflon and collar on end of shaft, set end play to 010" and reinstall fan and then reinstall pump.