Originally Posted by BIG RE

I don't know what car you have but as a general rule, if you can't get the nut to unscrew then either the wheel is stripped or you lost a roll pin. What you do in that situation is stick a flathead screwdriver in your outdrive to hold it stationary while you unscrew the nut, that should do it for you and then you can find the reason why it was not unscrewing in the first place.