I just put on my back wheel after getting new tires. After torqueing the axle nut to the proper torque, I was having a hard time getting the cotter pin to go through both holes in the axle. I could get it through the top, but then not through the bottom. It's almost like the axle nut doesn't go on the axle far enough to completely expose the hole in the axle. I did put two cotter pins in...on through one hole and bent it out from the inside of the axle, and another through the other hole. Is that OK? Anyone had that same problem?