While many car enthusiasts know how a differential works, very few actually know what one looks like inside while in action. Gale Banks of Banks Power put together a great video demonstrating exactly how a differential operates using a plastic cover and some unique engineering know-how.

Banks made this video while on a quest to determine if aftermarket differential covers actually provide any performance gains. In order to show the importance of the cover's shape, he placed a plastic see-through cover on the rear differential of an F-150 to provide a first-hand view of the gears in action. It's really cool to see how the ring gear acts as a scoop to fling the fluid up and around the housing.

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Banks explains that in order for a differential to lubricate itself properly, it needs an evenly rounded cover that's close to the ring gear to distribute fluid and get every part coated. If you were to replace the stock cover with something higher-capacity and a more squared-off look, the fluid would have a harder time traveling to the front of the differential—that's Bank's theory, anyway.

In a three-part series, Banks goes on to test the difference between stock and aftermarket covers, emphasizing consistency to get the most accurate information. Do aftermarket covers provide any measurable performance or efficiency gains? Well, Banks isn't finished with his study just yet, only having released the first two of the three videos so far. They explain exactly how he'll get the testing done. We can't wait to see the results.

From: Road & Track
Headshot of Brian Silvestro
Brian Silvestro
Lead Deputy Editor, Rankings Content

Brian Silvestro is Hearst Autos' Lead Deputy Editor for rankings content. He spent over seven years as a staff writer for Road & Track Magazine, and still contributes regularly with car reviews, industry interviews, and more. He also has a taste for high-mileage, rusted-out projects and amateur endurance racing.