There's no need to back up to unlock anything on your '94. The rear locker only functions in low range 4wd at low speed. It will unlock itself by one of the following: Hit the switch on the dash or, select high range or, exceed the speed in low range that the vehicle is programmed for. It's pretty fool-proof and tough.

You can use 4-hi/not-locked (the first detent in the transfer case shifter after 2wd) on the road without issue. That's all wheel drive with the center differential in the transfer case unlocked. Use 4-hi/locked or 4-low locked only on surfaces that allow slip, like dirt, snow, etc.

There are no locking hubs on your vehicle, unless someone added them. The front hubs are always locked, via flanges. You can therefore shift in and out of awd and two wheel drive on the fly.

Hope that helps.

John B.