This amazing piece of gearing has appeared on HowStuffWorks right before. You might figure out it from the electric screwdriver report. An automatic transmission is made up of two total planetary gearsets folded alongside one another into one component. See How Gear Ratios Work for an introduction to planetary gearsets. https://gearboxauto41739.designertoblog.com/65420304/new-step-by-step-map-for-gearbox-auto