Essentially , yes. Unless you have BLD - Brake Lock Differentials. My 95 GC has this. Back then, Command -Trac came standard with BLD. While the diffs are open , the BLD feature switches power from the slipping tire to the one that has traction. It works on both front and rear diffs. The effect is like crawling on all fours left/right/left/right, etc. It is sort of a poor mans locker system, but not nearly as robust. Fantastic on snow.
