How Is the Common Structure of Manual Transmission?

This is called the shaft assembly, the common structure of manual transmission. It is mainly made up of gearbox fork shaft, gearbox shift fork, positioning sleeve and synchronizer. There are also synchronizing gears matching with the synchronizer. 

Shifting process is actually that through the shift mechanism to push the gearbox fork shaft and gearbox shift fork, and thus pushing the synchronizer to combine with the corresponding gear, in order to achieve power transmission.

This photo comes from the network, from left to right are Gearbox fork shaft, Gearbox shift fork, Positioning sleeve and Synchronizer