Abstract: The invention relates to a transmission synchronizing device. A locating sleeve for the engaging sleeve is fixed on the main shaft. The locating sleeve is provided with radial bores, each housing a helical spring and a cylindrical element with a plate having a V-shaped cam surface for a roller. In the neutral position, the roller is lodged in a V-shaped groove in the engaging sleeve, thus providing it with a well defined neutral position. The roller is held in a hole in a pusher plate, which during gear engagement pushes a synchronizer ring against a cone on an engaging ring.