Performance of multicone synchronizers for manual transmissions

Abstract Theoretical performance equations are derived for multicone synchronizers which have replaced the traditional single-cone device in certain upmarket passenger vehicles. The equations are used to demonstrate the potential improvements in shift quality for a typical vehicle. Experimental studies of equivalent single- and triple-cone synchronizers within the same gearbox test rig are also reported for transmission oil temperatures ranging from cold start (0°C) to maximum operating conditions (75°C). The results confirm the overall much improved performance of the multicone synchronizer compared with the single-cone equivalent, except at low oil temperatures, where some difficulty in dissipating the oil from the multiple friction surfaces was apparent.