Ah, I ask as I bought a pair of bog outs and haven't had a chance to use them yet. A scenario like this was what I had in mind. THey do require at least one wheel to spin to work.It was kind of strange in that sometimes I would give gas and feel like NONE of the wheels were spinning. Other times just the rear axle would spin. Tried it with centre diff lock, but other than not moving, don't remember the results.