Abstract

The present invention relates to a synchronized change-speed gear unit for automobiles, having a pair of gear wheels which can be engaged into or disengaged from the power train by axially shifting an internally toothed gear-shift sleeve which is connected with a shaft via a guide sleeve so as to be torsionally rigid, an externally toothed clutch body being rigidly secured to the one gear wheel which is coaxial with the gear-shift sleeve; each clutch body is associated with a synchronizing ring which, in the circumferential direction, is in positive connection with the gear-shift sleeve and in frictional contact with the clutch body and which has a lock toothing permitting meshing of the internal toothing of the gear-shift sleeve with the external toothing of the clutch body at synchronous speed only. To reduce the gear-shift travel, the teeth of the gear-shift sleeve are axially extended towards the clutch body in at least two, preferably three places of the circumference and the synchronizing ring has lock teeth in the zones of the unextended teeth of the gear-shift sleeve only. The gear-shift travel reduction thus achieved is possible without increased power demand.