I know this question is probably proof beyond a doubt that I am an idiot. But I am not nearly the 4x4 expert no one believes I am. I noticed that when I took the "trollie" for a wheel alignment and balancing that the lovely little wheel caps on with the Nissan badge on the front wheels were missing. Hissing under my breath at the dealer trying to screw me over again, I went to inspect some further.
And low and behold, I saw that there is word written on it: "Lock"" and "Auto". Now I know the patrol has a rear diff lock (it does have a rear diff lock right?)? And has a nice button on the dash to proof it. But yes, what is it that is on the front axle of my patrol? And what is the function (see attachment)