Why are geared automatic transmission box dominantly planetary, whereas manual transmission use no planetary gearbox at all? What's the cons using linear gearbox in AT and planetary gear box in MT? -
![Front planetary gearset (total height 300mm, 4 pinions), with ring gear (82 teeth) and sun gear (38 teeth 43 splines), automatic transmission 0C8 TR-80SD used Front planetary gearset (total height 300mm, 4 pinions), with ring gear (82 teeth) and sun gear (38 teeth 43 splines), automatic transmission 0C8 TR-80SD used](https://maktrans.net/image/cache/catalog/vadim2/FPLANET0C8300/IMG_4017-800x600-1000x1000.jpg)
Front planetary gearset (total height 300mm, 4 pinions), with ring gear (82 teeth) and sun gear (38 teeth 43 splines), automatic transmission 0C8 TR-80SD used
![Dynamics 16-77| The planetary gear system is used in an automatic transmission for an automobile. - YouTube Dynamics 16-77| The planetary gear system is used in an automatic transmission for an automobile. - YouTube](https://i.ytimg.com/vi/9Ar-nnI4jRk/maxresdefault.jpg)