Im having a problem with the nut on the end of spindle trying to back off. I tightened it up a few days ago and it was fine for a day or two now its loose again. I can grab the wheel and pull it back and forth without raising it on a jack and I can always tell when it's getting loose cause I can hear a thumping noise when im driving it. I was wondering if it should be torqued or is it a hub problem, or is the spindle wharped or bent causing the nut to back off the spindle? If there is a torque spec for this nut what is the how much should I torque it cause normally the axel nut just has to be hand tight.