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This paper described implementation of a selectable one-way clutch in the GM's RWD 6-speed automatic transmission [1] content to replace the current one-way clutch and low/reverse plate clutch. A selectable one-way clutch can hold torque or freewheel in one or both directions depending on the desired operating mode. In this project, it is used as the reaction element to hold torque selectively in 1st gear and reverse. This paper describes hardware design, vehicle implementation, and control of the selectable one-way clutch. In additions, lower parasitic losses due to low/reverse clutch removal is measured and compared with production 6-speed RWD automatic transmissions. Other issues such as durability, cost, packaging, and mass are also addressed. This idea is demonstrated in a 6-speed RWD SUV. Vehicle results show very good static and rolling garage shifts as well as 1-2 upshifts, and 2-1 powered and coast downshifts.