Im baffled here. I am remounting the rear wheel on the 06YZ450f after getting a new tire. Everything looks good, the chain has the the correct slack set, everything is aligned and straight. The axle slides through the hub with normal (moderate) resistance. As I tighten the rear nut it will begin to get very tight like it should, then suddenly there is a very loud POP! If I continue to turn the axle nut it begins to get very tight and then a loud POP! again. I cant tell if the pop is coming from the axle or hub area...but my feeling is there is a great release of energy. Sooo, I pull the axle out and pop in the axle from my 2004 YZ450f....same damn thing. FYI...this happens at about 75 foot pounds on the torque wrench. (no it's not the torque wrench pop either ) Is there something in the design of the axle nut/axle that will only allow it to get so tight then it pops? Thanks for the input!