Hydraulically operated transmission having plural gear trains each selectively established by engagement of an associated hydraulic clutch. Each hydraulic clutch has an outer member and an inner member with the inner member being divided into at least a first inner part and a second inner part engaged in parallel with the outer member. A one-way clutch is interposed between the first inner part and the second inner part of each hydraulic clutch. The first inner part of each clutch is directly coupled to a member on one of the input side and the output side of the hydraulic clutch. The second inner part is connected to that member through the one-way clutch so that the one-way clutch allows overrotation of the second inner part when the member is on the input side and overrotation of the member when it is on the output side.
