Originally Posted by NoHyperbole

Regarding tightening the rack and pinion nut, I too have a 2014 coupe and was experiencing "loose" steering, as evidended by the steering wheel doing a quick left-right-left-right shimmy when I hit bumps in the road that affected only one front wheel.

I brought the car to the dealership, and the tech tightened that nut about one full turn. That made an immediate huge difference in steering feel. On-center feel was much more pronounced, and the steering generally had more heft and resisted the aforementioned shimmy. HOWEVER, the steering would no longer self-center when making a turn; I had to manually guide the wheel all the way back to center. So I returned to the dealership and had them loosen the nut 3/4 turn, which cured the new problem and caused the old problem to return.

I spoke to a Nissan master tech who works at an independent shop, and he said never to tighten that nut, as it casuses the gears in the steering to bind, which is obviously detrimental long-term. So yes, this is yet another case of a dealership's service department not knowing its products well enough to implement the proper solution, which in this case may be replacement of the steering rack.