Originally Posted by MouSe
Are you asking about the large nut that is in the center of the hub that you can see once you pull the drum off?
Sorry, no that'* not it. I have a 1 ton and the front wheel studs have an extender that attaches with 8 standard hex nuts. That extension has 8 of its own studs which is what the tire attaches to with wheel lug nuts. It'* there for compatibility with the deep rims that are necessary on the dual real wheel so that the wheels can be rotated back to front.
Hope that makes more sense. I should have snapped a pic and attached it to my original post. Doh!