Not a dumb question, excellent question. With knob in, normal use, only 1 axle out of the 4 will drive, unless your 1800 has "Positive traction" shifting power to both axles on 1 differential, but I think that would be another knob. Either way, with the power divider not in use, only 1 differential will drive, and that is the one that will spin the easiest. With the knob out, power will be sent to both differentials. You can pull the knob out sitting still, or in normal motion, BUT NEVER pull the knob while stuck and spinning. If you look ahead and see you might need extra traction up ahead, pull the knob before that happens.