This remarkable piece of gearing has appeared on HowStuffWorks before. You might recognize it from the electric screwdriver write-up. An automatic transmission consists of two comprehensive planetary gearsets folded alongside one another into 1 part. See How Equipment Ratios Work for an introduction to planetary gearsets. The automobile gearbox or https://simoncikki.thezenweb.com/rumored-buzz-on-gearbox-auto-72169883