The invention refers to a shift transmission synchronizer (1), comprising a synchronizer shell (4), a sliding sleeve (9) and at least one synchronizer ring (11,12), wherein the synchronizer shell is torsion resistant and is axially fastened to a transmission shaft, and the synchronizer shell is provided with an external tooth part (8) equipped with one or more vacant positions (5,6,7). The sliding sleeve (9) is provided with an inner tooth part (10) and can be axially and slidingly connected with a shift gear. In addition, the at least one synchronizer ring (11,12) possesses one or more axially oriented raised projections (13,14) which extend to the vacant positions (5,6,7), wherein one or more raised projections (13,14) possess radial and axial metal outside surfaces (15 to 18), and the radial metal outside surfaces (15,16) are provided with a damping coating (20).