I was unlucky enough to recently purchase a Nikon D800 with a misaligned left autofocus sensor. Anyone purchasing a Nikon D800, even as late as 2014, should check for this problem. You can find out more about this problem and how to test for it reading this detailed article from bythom.
Fortunately, the repair request is pretty simple. Just go to Nikon Service and Repair to schedule a repair online. They give you something to print out and ship with your camera. Also, you have to include a scan of your sales receipt and warranty card. Don’t pack your camera in its original box or you won’t get it back. Also, be sure to take out the battery, memory cards, and lens. They suggest insuring the package, which can cost a pretty penny. So be prepared to fork out the cash to ship it.
Nikon D800 Left Autofocus Repair Timeframe
Reported results have been mixed from D800 owners who return their camera for repair. Some have reported sending their camera back repeatedly before the issue is resolved. To my good fortune, I live in New York, close to a repair center, so the camera itself arrived at the center in a day. From that point, it only took two business days from receipt of camera to ship it back. I received a couple of emails during the whole experience, one to acknowledge receipt of camera and to outline repair. The final email was shipping info from UPS.
I am glad to say that after testing the camera again, I can report that the left autofocus issue is fixed. I now have a working camera. All in all, from New York, it took a week from sending it out to getting it back.