Excellent post. You even used the proper terminology! I read the title of this thread and I was like, what? Lost the "keyway"?Another trick I learned from the Youtube video to secure the woodruff key, is prior to installation, take it out, lay it on it's side, using a center punch and hammer, strike it a couple of places on each side to raise up some material. Then gently tap it into the machined keyway slot, with the arrow pointing towards the pump. This gives it a snug press fit. It stayed in place for me last week. I didn't have access to any super glue at the time. Good luck!