An installation for assisting the meshing engagement of a reverse speed gear wheel in a change-speed transmission intended in particular for motor vehicles, in which the reversing gear is constructed as sliding gear wheel and is adapted to be engaged with the gear wheels on the counter shaft and on the main shaft by means of a shifting element; the gear wheel on the countershaft is thereby wider in the direction toward the sliding gear wheel than the gear wheel on the main shaft while a brake constructed in the manner of blocking synchronizing device which cooperates with a fixed part of the transmission is coordinated to the sliding gear wheel.