btw all drive axles have a differentil but the way they function is different depending on how they are built and intended useage.

to also add.....a 4wd from the factory unless equipped with a locker is not a true 4wd since it uses a limited slip setup which means at any given time only two wheels are actual drive wheels when in 4wd. The locker binds both wheels on an axle in order to make them turn at the same speed which allows for more traction.