The H1 has Torsen differentials which are a little different than lockers, they apply a torque bias ratio bewteen the wheel that spins and the one that has traction. So a torque bias of 5:1 would send five times the torque to the wheel with traction. That's why if your hummer can't get traction they tell you to lightly press the brake to trick the torsen into sending power over to the wheel with friction. It's like a cross between a locker and an LSD.

Lockers split the torque 50/50 (ratio 1:1) between the two wheels, no matter what.