Front Locking Hubs

[tuckertrucker]

Hi guys and gals, can anyone explain to me in relatively laymans terms how the front locking hubs on my safari work? They have the usual dial used to select between the two modes. I'm not too sure what they mean though - one position is "LOCK" and the other is "AUTO". When in auto the front diff is LSD/Open (not sure which) and when in lock they are locked. So if I put the truck in 4WD and leave the hubs in auto, it IS in 4WD and the front wheels ARE driven, but is I hit soft ground the lightest wheel will spin, and if I get out and select lock on both wheels, the diff is locked. So my question is how does this work? Is it safe to drive around (on road in 2WD) with the front hubs locked?
Cheers

[Hodge]

When hubs are on AUTO. Once 4WD (transfer-case) is engaged, you have drive to front drive shaft and in turn the front axle. So hubs will lock when you move forward. You now have drive to all 4 wheels. They will also UNLOCK once you go out of 4WD (transfer-case).
The reason the lighter wheel spins is because you do not have a front locker. Also I don't believe there is an LSD in the front? Someone correct be if I'm wrong.

When hubs are on LOCK. They are exactly that "LOCKED". Your front diff/axle/driveshaft will spin regardless of where the transfer case lever is. They will also NOT UNLOCK once you go out of 4WD (transfer-case).

[TimE]

.... and my hubs in "Auto" mode would occasionally unlock in reverse ............... damb nuisance when trying to back up hill out of a muddy rut.

So if you are going to need 4wd for any length of time put the hubs in "Lock", they will stay locked until you return them to "Auto".

I replaced my auto hubs with AVM HP hubs and put an elocker in the front ............ love it this way :)

[tuckertrucker]

So basically if I'm not doing any serious 4WD I don't need to lock them as when i engage 4WD they will automatically lock. But will unlock when I disengage 4WD. When theyre locked, is there still LSD or does it lock that?

[tuckertrucker]

Ahhhhh!!! I just read something that made what you said make sense. Until now i was too clear on the difference between diff locks and hub locks. So basically the hub locks lock the wheel to the axle, and the diff locks lock the half shafts together in the diff. So when my hubs are locked, I've still got LSD or Open Diff (still not sure which) but the wheels are driven.
So with that being the case, and the diff is open or LSD, why can't you just drive around full time with the diffs in LOCK? It'd be the same as the back axle just not driven.

[TimE]

You could drive around with the hubs locked, but you will be turning the axles and diff thus using more fuel for no practical benefit.

[Winnie]

So basically if I'm not doing any serious 4WD I don't need to lock them as when i engage 4WD they will automatically lock. But will unlock when I disengage 4WD. When theyre locked, is there still LSD or does it lock that?

Yes. For example, if you are going to quickly put it in 4WD to get across a wet paddock or something like that, auto is fine and you don't have to get out of the car.
If you are going 4WDing though and hitting the tracks, lock them in for sure.

Your front diff is not an LSD, it is an open diff so more power is applied to the wheel with less traction.

[tuckertrucker]

Handy to know. I just had a look and found that TimE is right, although mine always unlock in reverse if theyre in auto.
Right, so when I do the manual conversion a diff locker is now on the list too. This project list is getting better and better every day!! I may need another job....

One other thing - when I come out of 4WD I have to back up about 1m or until I hear a clunk. Is that clunk the rear diff lock unlocking, or the front hubs unlocking?

[Winnie]

That is the front hubs unlocking.

[tuckertrucker]

So when I have the front hubs locked, and say im on a slippery surface, I can eliminate the lightest wheel from spinning by driving through the brakes- correct? Doing that would create an equal resistance across all four wheels and so equal drive would reach all four wheels, or close to equal.

[Winnie]

It will certainly help, and send more power to the wheels with less traction. But definitely not close to equal drive.

[tuckertrucker]

Bummer. Well, the front diff lock is on the list. Would you recommend getting a manual diff lock on the rear? Or are the factory automatic ones fine.

[Winnie]

Standard Nissan LSD is pretty much one of the best on the market. Obviously a manual locker would be better but some would say not necessary.
I am going to order my front locker in a couple of weeks and am going to keep the Nissan LSD.

[tuckertrucker]

This is one area of the truck I knew very little about. So the rear LSD doesnt have diff lock. When I get around to the suspension I'll see about lockers on the front and back. At this stage I'm planning an Auto to manual conversion, 2 inch suspension lift and 32" Maxxix Bushshot tires, Lockers font/back, new floods on the roof rack that Im also gonna get. Then maybe after that I'll look at this 6BT Cummins conversion. But thats a maybe for waaaay down the track.