This awesome bit of gearing has appeared on HowStuffWorks prior to. You could possibly acknowledge it from the electric screwdriver report. An automatic transmission is made up of two full planetary gearsets folded with each other into 1 component. See How Equipment Ratios Work for an introduction to planetary gearsets. https://gearboxauto87417.howeweb.com/34792830/new-step-by-step-map-for-gearbox-auto