Synchronizergear hub is made of PM, with more complex shapes and different thickness section.
同步器齿毂的材料为粉末冶金，形状比较复杂，而且截面的厚度不一样。
2
Out-of-mesh trouble in 4th gear was found in actual usage, but the trouble is solved by changing the synchronizer structure, increasing the rigidity of the synchronizergear sleeve and etc.
Shift actuator has five different types, such as sliding gears, gear sets, synchronizer, gear clutch and free wheel. And the synchronizer is widely used in automotive transmission.