Transmission

A transmission (111) for a working machine including a drive transmission mechanism (123) and a working transmission mechanism (122) operated by swinging a shift lever (36) is provided. The drive transmission mechanism has a key-sliding transmission mechanism (138A) axially mounted on a drive shaft (78). The key-sliding transmission mechanism causes a selected one of a plurality of gears (139B) rotatably mounted on the drive shaft and the drive shaft to rotate together to transmit power to drive wheels (13, 14).