This is standard for anything that is not constant 4WD and is yet another reason I went to the 200 Series Landcruiser. In the 200 series you can drive around in low range on the bitumen with no issues. In the 100 series it required a minor electrical mod to disengauge the Automatic centre dif lock when low range was selected. The only way you can avoid it with a "normal" 4WD is if you have manual hubs on the front end and don't lock them in.