You need to get a REAL socket and breaker bar and put a cheater bar on it. Should be 3/4 drive and a GOOD brand. I'm sad to say that Craftsman no longer cuts it when it comes to doing heavy duty work. I have to work on heavy duty tractor stuff and a 3/4 craftsman will twist,bend and crack like it's made out of plastic. The guaranty is great but it doesn't get the nut off. Get Snap-on, Mac or S-K etc. You can also go to a discount store and buy a honkin big box wrench for a couple of bucks, cut one end off and slip it into a long piece of pipe right up to the head of the box. It'll work for a one shot. Box wrenches are pretty tough. Remember, "Don't force it. Use a bigger hammer".