This video is part one of a seven part series covering basic automatic transmission operation. In this video, I cover the simple planetary gearset -- sun, carrier, and ring gear. I discuss how there are six reduction and overdrive combinations and I also discuss how to calculate gear ratios on a planetary gearset. I introduce combination gearsets, like the Honda 10-speed, 4L60E, 41TE, and the Ford 6F50 and discuss how a simple planetary gearset relates to these more complicated gearsets.