With a standard differential without "Positraction, a limited slip differential, a Detroit locker, etc. engine torque goes to the free spinning wheel. For instance, take a traditional differentially equipped car. Jack up the rear end with both wheels hanging in the air. Use something to grab one wheel to prevent it from rotating. When you speed up the engine, the one wheel hanging in the air will spin. No torque will be delivered to the wheel you've restrained from rotating.
With just a standard differential, the up-in-the-air wheels would be forcefully spinning and no torque would be going to the supporting wheels. With a "Positraction" (limiited slip differential), the torque and power would be going to both the wheels; the ones in the air and the ones on the ground.But the up in the air wheels in the video are turning.
I would guess that the drive shafts to the left side wheels were disconnected.
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More about differentials. When I lived in Australia (1986-1991) I had an Australian Range Rover. I had an ARB (an Adelaide, South Australia company) install a install an air locker on my rear differential. First of all, I could lock out the transmission four wheel drive differential (standard Range Rover for the four wheel drive), and then with my ARB rear wheel differential locker, I could lock out the rear end. For this Range Rover to get bogged down, I had to have 3 wheel all spinning to loose traction. Did I ever loose traction? Yes. Once. Driving off road I tried to drive over a big Spiniflex plant. It's a big grass like plant that grows in a clump in the desert. I ended up with all 4 wheels in the air. I wasn't going anywhere. Another driver (Toyota) winched me off the clump. I later learned that getting stuck on one of these Spiniflex plants was very dangerous if you have catalytic reactors. The hot reactors can get the plant burning....it's all downhill at that point.
