The "physics" of the locker won't change that it's *going* to cause one or both tires to slip in snow or ice, 2wd or 4wd, doesn't matter...
Correct, if a tire doesn't have enough traction to grab, its not going to grab, no matter what gear you're in or 2wd or 4wd.
The physics do dictate that you can change how MUCH traction a tire has for propulsion, or turning though, because the contact patch has a limited amount of traction, and, if you use some of it to change direction, you have less of it for propulsion, and, visa versa.
This is WHY you are (Most are at least, if it came up...) taught to coast in the turn if its slippery enough, as if you are on the gas, you have less traction to make the rig change direction...and you tend to make a wider turn (understeer) or in extreme cases, just plow straight with the wheel turned, etc.
This is the physics used in drifting for example. You can use the throttle to steer with depending on the balance of the vehicle. Inducing spin on purpose is used to swing an end around, and getting sideways but facing the exit acceleration direction, and using a 4 wheel power slide to get through a turn by adding a little propulsion to the crabbing to make it around the turn and then hooking up already facing the right direction, and so forth, all take advantage of that physics.
So a locker can't make your rubber stickier, and, if it is fully locked w/o differentiating, it FORCES one tire to slip in a turn, because it is NOT differentiating/allowing the outside tire to make more revolutions because that tire is on the longer, outside track.
A locker that ALLOWS differentiation acts more like an open diff would, in that it DOES allow the outside tire to go faster if it needs to.so the outside tire can freewheel around the turn, with ALL its traction being available for steering as none is used for propulsion.
The INSIDE tire under those circumstances is still powered though, unlike the open diff that coasts the inside tire and powers the outside tire.
In a turn, the inside tire has less leverage than the outside tire, so the traction and steering input of an inside tire is less than that of an outside tire.
In a straight line, the open diff and the locked diff are doing the same thing...both tires are powered.
In the turn, the open diff, assuming the outside tire has some traction, it's powered, and the inside tire is coasting...so the propulsion is ENTIRELY from the outside tire, and the steering is MOSTLY from the inside tire with some help from whatever traction the outside tire has left.
In the turn, with a differentiating locker, the opposite happens, in that the outside tire is coasting, and the inside tire is powered...so that the propulsion is ENTIRELY from the inside tire, and the steering force is MOSTLY from the outside tire with some help from what ever traction the inside tire has left.
The above difference is typically subtle but can feel different, and depending on the rig, can require various degrees of familiarity to get used to.
For example, the traction for pulling or turning is going to come from the opposite side you were used to...so the handling in transitions will feel "different".
The side that used to bite and pull but not steer as well, is making you turn more but pulling less, and the side that used to steer you more and pull less is now pulling more and steering less.
The act of disengaging the gears on the faster side is a small amount of tire rotation, a few degrees...and if slippery enough to not rotate the tire itself, the side will not differentiate/disengage.
In other words, when going around a turn, a diff doesn't KNOW there's a turn, the ROAD is simply rotating the tire faster than the drive train gearing is rotating it. This works for a simple little red wagon with no gears at all, just a shaft between two tires, or a car, etc.
If the turn makes the road rotate the tire faster, the differentiating diff lets it. If its an open diff, its designed to only POWER the faster side though. If its an autolocker, its designed to CONTINUE to power the slower tire and let the faster one go unpowered by letting that side's gears ride up if the road rotates them faster than the drive train gears.
So the road is what disengages the autolocker's faster side...the same way is ENGAGES the open diffs faster side. The difference between them is that for the autolocker, the slower side is powered instead of the faster side....and there are NO cases where NO side is powered.
The Lokka -
Starting from straight ahead, it's driving both axles with the Cam gears meshed to the Axle gears.
When one tire starts to roll faster than the Cam gear is driving it (when cornering), it rolls off the cam altogether, then the little teeth ride up and separate the Cam/Axle gears...... so the outer side tire (which is now turning faster) is able to 'free wheel' around the corner.
That's how it disengages that one side for turns.
