Mitsubishi Montero Forum : “using 4wd”

Check your owner's manual.  There should be a switch somewhere with 4wd and 2wd on it.

I just bought this car used and it did not have an owners manual. I can't find a free download for one on the web, does anyone know a website to get FREE owners manual for a Mitsubishi Montero?

There's a shift knob next to the manual/auto shifter.  If you have an air locker then there's a switch at the bottom of the center console.  If the air locker won't disengage then you could probably just disconnect the air pump for the locker which is located under the rear seat in a compartment on the passenger side of the vehicle.