This amazing bit of gearing has appeared on HowStuffWorks just before. You could understand it from the electric screwdriver posting. An automatic transmission is made up of two total planetary gearsets folded collectively into 1 part. See How Gear Ratios Get the job done for an introduction to planetary gearsets. https://gearboxauto28394.blogtov.com/14644085/5-essential-elements-for-gearbox-auto