Abstract: A transmission shift device includes a rotary shaft rotationally connected to an input shaft of a transmission, first and second clutch rings rotationally connected to an output shaft of the transmission at a first gear ratio and a second gear ratio, respectively, a clutch hub fixed to the rotary shaft between the first clutch ring and the second clutch ring, a sleeve restricted a relative rotation with the clutch hub and movably engaged with the rotary shaft in the axial direction, first and second dog clutch portions projected from respective side surfaces of the first and second clutch rings and engageably and disengageably meshing with sleeve spline formed at the sleeve, and an elastic member positioned between the clutch hub and the sleeve and restricting a movement of the sleeve in the axial direction in each of a neutral state, a first shift state and a second shift state.

Abstract: The invention relates to a synchronization piece which, as part of a servo synchronization system comprising a sliding sleeve, a clutch body, a synchronizer ring and an idler gear, can synchronize a transmission having toothed wheel gears. The invention furthermore relates to an entire synchronizing system having a synchronization piece according to the invention. A full-servo synchronization system is also presented.