H3s have a 4x4 auto button on them?
I thought is was only 4x4 open, 4x4 locked, and 4x4 low
I stand corrected on my initial assessment of the H3's drive train. Here is the difference between AWD and 4x4 all the time you were correct as was I. The differences used to be, AWD as a general rule does not have a t/case that supplies a low gear ratio(no 4x4 as i said). In addition, AWD systems have a system, using either clutch packs or electronic solenoids to vary the amount of torque between the wheels(As does the traction control on the H3). Example, with an AWD system, where the primary drive axle is the rear, it can vary the torque between front and rear. Most of these systems have about 10-15 percent of the torque to the front wheels, remainder to the rear; however, this can be varied up to 50/50 by either clutches that slip, or a solenoid controlling a circuit via input from a controller. Same is true with a primary front wheel drive vehicle.
Full-time 4x4 (like Hummers), have a t/case that offers a lower gear ratio(4x4) and takes manual input from the operator of the vehicle to change the front/rear(Electronic control) torque ratio.
Now, since 2005 with the car industry and the SAE boards, there have been some new systems released that are a combination of AWD with full-time 4x4(H3) so the waters are getting murky. However, Hummers, per SAE designation, can be classified just as full-time 4x4 vehicles or AWD. And Hummers split is as so- 4hi - 40/60 split on the power front/rear
4hi locked - 50/50 split on the power while still in a higher gear ratio so you can drive a higher speed than rock crawling such as a snowy road
4lo locked - 50/50 split on power with lower gear ratio for low speed crawling type situations
