I don't have a switch or anything for that. I'll have to look and see, because right now I have no idea.
I wonder if that would help.... I know we have an air locker that locks the dif. and it has gotten me out of a couple situations where I needed a little bit more traction. That might be a solution to your problem. Then you would have both sets of tires spinning and not just one....probably have limited slip. but by the time it would kick in its too late.