Not true, but you dont know me i guess. I use mine weekly off road, and find that if kept clean and lightly lubricated they are fine. I do lock mine with the spanner if getting serious with the C/T in tow. When I got my patrol the left side needed lubricating, it woulndt dissengage propperly and would click until I had backed up sufficiently to hear it click out. If I were you I would remove it, and flush it out with crc or petrol or degreaser and then then blow it dry and apply a small amount of light oil and see if it rectified. It could be stuffed, but it could be sticky too. They dont need a handful of grease!Ahh yes, I assume you still have the factory auto locking hubs? Well to put it lightly, they are weak as piss. You need to do a manual hub conversion. Everyone I know who has taken there GU offroad has had to replace them.
I have certainly found that I need to manually lock the hub and rotate it to get it back on properly. I dont have the manual.There is a procedure for removing and installing the hubs as per the manual.
I never used to follow it to the book until I took a hub off one day and when i put it back on it would click and not function correctly.
Mark the relation of the locking hub to the housing it bolts to, MANUALLY LOCK THE HUB and remove it. What I do then is mark the position of the inner dog gear or whatever you wanna call it then remove that to adjust a bearing or whatever.
Refit aligning said marks...give the wheel a spin then UNLOCK the hub and give it another spin.
Worked for me.