Ah Paco, so you do not know the history of the camera. One quick check is to mount a D lens and see if it will AF. If not the mount is deformed which, with that body, means the body could also be bent out of shape . That would make it more expensive to repair. Great camera and hated to sell mine but I was not using it as much as when I was shooting lots of Sport. Get it to Nikon and see what they say.
Hope it is simple and CHEAP (ish).
Tom
Sounds a bit dark these predictions
A body bend out of shape,,, wow,,, would leave some huge marks from such an impact, also would make the body visually crack open, since the casting is super hard/brittle,,,Sure the mount can de off from small/big bumps but that is usually quite obvius if you take a close look
Most likely the sub mirror or the AF module is slightly off, but really you need Nikon Service to look at it.Good luck and enjoy this Iconic camera, the first real full frame Nikon DSLR - I loved mine.
BTW what is this fault finding using a D lens,,, why would that indicate anything except the screw af motor ?