To obtain the transmission into overdrive, lots of points have to be linked and disconnected by clutches and bands. The Earth provider will get linked to the torque converter housing by a clutch. The compact Sunshine will get disconnected with the turbine by a clutch so that it could freewheel. https://gearbox-auto13458.goabroadblog.com/32894059/5-simple-statements-about-gearbox-auto-explained