A transmission includes an input shaft for receiving rotation of an engine, an intermediate shaft connected to the input shaft via a damping mechanism, drive gears, driven gears, and an output shaft. Rotation of the input shaft is transmitted to the driven gears, which are inserted into the output shaft to be free to rotate, via the damping mechanism, the intermediate shaft, and the drive gears. A gear shift is performed by fixing one of the driven gears to the output shaft to be incapable of relative rotation using a selector mechanism. An impact generated when the gear is fixed is absorbed and dampened by the damping mechanism, which is interposed between the input shaft and the intermediate shaft.