Nissan Patrol 4x4 (Africa)

I leave mine on auto in town and the occasional curb climbing or off tar incident. But like Peter if I go playing ,or off tar , or even where I will 4wd every day - I'll switch to lock. My understanding is that it unlock when you change direction , thus when locked in forward, when you revers in 4wd in will unlock en lock for the reverse direction.

Nothing wrong with either. You can leave it locked or on auto and you should never have any problems.

The only thing to note is if it is in the auto position, it can unlock when you roll backwards. If you reverse normally it shouldn't unlock.
Even if it unlocks, it will lock back pretty quickly. The only time you ever need to worry about auto locks on the hubs is if you rolled back on a steep incline. DO NOT just put your foot down. Pull away slowly to allow the hubs to lock again before giving it too much power.

I don't think I've ever taken mine out of auto and I know a couple of people who rarely ever take it out of locked.
Your choice really. I suppose you could change it every time for whatever terrrain you find yourself in, but I just don't think it's worth the hassle.

I know this is an old post, but having broken just about everything that it exists, I felt I had to give "my 2 cents"...

As far as the initial question: Lock them manually when you get off road, it is just better and more reliable. You get out, you lock them, you know they are locked, and they don't "get confused" and come undone. ; however, if in very good condition -- thing that you are never able to tell untill after you've used them -- you should not have to worry about them comming undone, since the torke sent by your shaft will keep them in place. No design problems there

However my friend, auto hubs are crap, not just nissan but all of them. They are all unreliable, and they always give when you least expect them and need them most . My advice to you would be : Take those out and put on a set of manual nissan hubs, like the ones used on Patrol Pick Up's; well not "like those", "those"! .

Once you start moving on to the bigger tires and differential locks, you might one to consider something more aggressive such as Superior's chromoli hubs, but for now: Lock them manually, specially on rocktrails.

Here's a cool video that might entertain a few... Cheers!

tanks man great link