I believe it is either a 9/16" or 5/8" hex that fits the tube that connects to the spare tire winch. I made up an adaptor that has the hex to fit the tube on one end an a 15/16" hex on the other end that is the same size as the lug nuts so I could use an impact wrench to lower and raise. I got the hexes by welding a nut on each end of a rod.
Kevin