bkusich, What kind of mower are you working on? I'm sure one of us here on OTT has one like it. Mine is a Bush Hog brand and has right handed threads. It has a washer lock (not right name, but what I call it) that you bend up on the side of the nut to lock it in place. Yours may have left handed threads. Also if you could post a picture or two, it would help. Keep us posted.