Replaced the impeller today. A little piece was broken off and the impeller blades were "lop sided", one side of the ears were bent more than the others. Also when I took it out, the cup came out with the housing, then I had to take the ring and compression ring off, so not sure if someone had put it on wrong. I had ordered the kit. The woodruff key was in there "good", I opted not to pound on it and take it out. I cleaned the bottom plate real well. I actually had to put the impeller in the cup then slide it on. Had to turn the fly wheel a little to get it aligned up. Pretty easy job though. It tested well on the muffs, I will take it out this evening for a double check. Thanks to all who posted tips.
Allen