I hear you- seriously. Torq-masters does not want us to say 'un-lock' and @jay_man81 kind of explained it incorrectly. Here's the deal: When you turn, let's use a full circle as an example... If you put paint on your tire treads, and gently make a full circle with the machine, the outside tires will draw a bigger circle than the inside tires. In other words, the outside tires have to travel further than inside tires. The auto-locker will allow the outside wheel to overrun the inside wheel, if there isn't much power being applied to the diff. If you try to make the full circle with a bit of power, it will lock up like a spool. I don't like to use the word 'senses' when we talk about a mechanical operation- so here's what's going on in there: The middle section of the locker has a 'cam' gear on each side of the cross pin. You have to understand that it's the cross pin that is actually driving everything that drives the axles, whether you have the spider gears in there, or a spool, or an auto-locker. So, the two cam gears are pushed apart by the ramps on the cam gears and pushed towards the axle gears keeping them engaged at all times, BUT, under light load, there isn't as much force pushing the cam gears into the axle gears so the precisely machined engagement 'teeth' will allow one wheel to over-run the other, because the lack of torque pushing that particular cam gear towards the axle gear will allow the ramps on the engagement teeth to overcome the cam gears force, and, click-click-click, it 'ratchets' allowing that wheel to turn faster than the other wheel, but, there isn't enough clearance to allow both to disengage at the same time, so the wheel with traction can never slip because 1st, there isn't enough clearance in the unit to allow both cam gears to disengage at the same time, and the cam gear that has torque applied is forcing the engagement teeth together. That's what the 'spin-test' proves. I know the auto-locker looks simple, but, in operation and construction, it's actually very complex to get it to work properly- the cam angles, engagement tooth profile, spring tension, and clearances have to be insanely precise for the unit to operate as amazing as it does. If you had ever tried one of this style of lockers 20 years ago, you would probably have been as skeptical as I was about what to expect. As far as operation- Torq-masters has nailed it with this one.
None of the explanations I've seen have explained clearly how this works-I.M.H.O. I think I'll do a video when the heat-treated unit arrives. I hope this is helpful