What size are the mower blade spindel bolt head, to remove blades? Book says 30.2, but have a 30mm and won't go on. Also have a 1 1/2" and its to big. A 31mm would be about right, but don't seem to make one. Will 1 3/16 work? Its about same as 30mm. I am tired of fighting trying to hold a wrench on top spindel nut and bottom blade bolt and hold a board in deck to keep blades from turning, all at same time. I need a impact socket, what the devil size will work? Thanks hjt