Abstract: A transmission has a pair of hydraulic motors for hydraulically driving crawler type vehicles. The hydraulic motors are connected by a drive train having rotary members. The hydraulic motors are disposed such that a rotary axis of an output shaft on one hydraulic motor is offset from a rotary axis of an output shaft on the other hydraulic motor. A clutch is provided between one output shaft and another rotary member, which is coaxially disposed on the one output shaft. The clutch in accordance with the invention improves the accuracy of straight forward movement of the vehicle. In accordance with the invention, when a steering unit for steering the vehicle is moved to a steering position, for turning the vehicle, and a non-steering position, for straight forward movement of the vehicle, vehicle impact and clutch damage are reduced. The transmission can also be made more compact. In addition, a parking brake can be equipped on the other output shaft.