Auto or manual? Manual of your truck will have the m226 which is a modified Dana 40. Auto will have the c200k which is far more limited in locker options.
Unless you put in a limited slip carrier, you have an open diff. Nissan never offered a limited slip rear end on 2nd gens. What you are feeling is the ABLS (Antilock Braking Limited Slip) and traction control nannies kicking in. This uses the brakes to control wheel spin at each wheel.I have the auto, currently have a limited slip diff, that kicks on when I usually sliding around in the mud. I want lockers, dont mind if they are electric or manual.