Do you ever wonder how exactly a differential works? We all have a rough idea, but for a well-explained breakdown of the concepts, check out this instructional film from the 1930s. I think you’ll be hard-pressed to find a clearer explanation.
For some extra fun, compare it to this Audi Quattro video in which it’s very difficult to understand exactly how a “torque-vectoring” center differential works despite the pretty graphics.
Btw: isn’t 4-wheel-drive so much better than 1-wheel-drive?