Abstract: A transmission has a drive train which is coupled with the engine, e.g. an automotive vehicle and a reversing gear connected to the output shaft. A slidable gear shifted on a fixed shaft, continuously meshes with a gear of the drive train and can be brought into mesh with the reversing gear for reverse drive. According to the invention the shiftable gear is connected with a synchronizing ring which has a frustoconical surface engaging the frustoconical surface of a synchronizing disk which is keyed to the fixed shaft when the slidable gear is shifted toward the reversing gear to stand still. The synchronizing disk or member on the shaft can be entrained with the sliding gear upon overcoming the force of a detent formed by a bore on the fixed shaft which is biased outwardly by a wedge member and an axial spring in the fixed shaft.