2000 3.9l 4x4. NV231. If I shift the transfer case into 4lo it won't engage. The gears will just grind. I have to put the transmission into neutral and shut off the engine. It's the same when shifting back to high. Is this just wear or can it be adjusted?

 

4 Lo isn't synchronized, so, you either have to shift FAST, or, do exactly what you did. I try and shift into 4 lo when moving VERY slowly. Less than 5 mph. Usually works.