Does this happen from a stop? Or is it most noticeable when you are changing directions (i.e. R to 1st or vice versa)? Assuming it is the rear axle click, greasing the axles is what Nissan will charge you $160 to do and is just a band-aid for most. Do it right and replace the adjusting cap which is typically the source of the noise (go ahead and grease the axle faces as well). This thread has all the information you need:
FIXED: Rear axle click clunk noise.