To be honest its was probably like that when I bought the car some 5000km ago. It didnt wine, didnt rattle. There was the occasional click when I went from neutral to first. a few other random noises from the back that I had assumed was the cracked subframe which was the reason behind pulling the diff in the first place.
Tony from Steelie gears who has the diff at the moment said it is a flaw in the first gen g series diffs, he has a bunch of hilux housings that are the same issue and that in the later ones the ring gear end is thicker which prevents this from happening.
My car has had a hard life from the previous owners so axle tramp has a lot to do with this.