[aa0]

That was a great video, thank you! Knowing basic gear mechanics helps a lot in understanding how cars function.

This 1937 video about differentials is also enlightening:

http://www.youtube.com/watch?v=yYAw79386WI

Why is it that old tutorial videos are so thorough and informative?

[jaxb]

There was no Internet to fill in the details?

[mikeash]

It was also a big deal to make a film like this. Today you can just prop up your phone on something and go to town, but these videos would have been a huge amount of work. Once you're putting in that much work, you had better make sure the result is good.