My D700 workhorse goes to Nikon every six months whether I'm aware of something it needs, or not. At the very least, I send it and the 70-200mm 2.8 VR in to the Nikon service center for a "clean and calibration".
Nikon will go completely through the equipment and return it to factory specs (assuming it's a USA body of course, and not gray).
Your first repair can be fairly costly depending on what they find (but still far far less then replacing that body), but once returned to factory specs, Nikon puts a new, 6 month warranty on the equipment.
Nikon has replaced grips, bottom plates, battery door covers, shutter arms/levers, front elements, mirror arms - and so much more. And as long as you are in that 6 month warranty window and it's not water or impact damage, you should be good to go.