(Automotive engineering: Vehicle components, Engine, transmission, and exhaust)
A synchromesh gearbox is a usually manually operated transmission in which a change of gears takes place between gears that are already revolving at the same speed.
It is often claimed that a synchromesh gearbox requires less effort to change gears.
Before the synchromesh gearbox was introduced in the 1930s, every driver had to master the difficult task of double-declutching.
When the manufacturer advertises a car as having a synchromesh gearbox you cannot expect to have synchromesh on the first gear, and never on reverse.