This amazing piece of gearing has appeared on HowStuffWorks just before. It's possible you'll identify it from the electrical screwdriver post. An automatic transmission consists of two total planetary gearsets folded with each other into 1 component. See How Gear Ratios Do the job for an introduction to planetary gearsets. https://cristiannrokg.blogthisbiz.com/40985163/gearbox-auto-an-overview