Thankfully, your car’s differential doesn’t need to be replaced very often (if ever). It chugs along mile after mile without a lot of drama. Maybe that’s why the inner workings of a differential are a big mystery to a lot of people (myself included). If you’ve ever wondered how a differential works, you gotta check out this video tutorial. Not only is it extremely easy to follow but it’s extra cool because it was made in the in the 1930s, so it’s got a lot of cool historical flavor (black and white, old-time music, etc).