This remarkable piece of gearing has appeared on HowStuffWorks prior to. You may realize it from the electric screwdriver posting. An automatic transmission is made up of two comprehensive planetary gearsets folded together into just one element. See How Equipment Ratios Function for an introduction to planetary gearsets. S usually https://gearboxauto18407.blogzet.com/detailed-notes-on-gearbox-auto-48921792