The transmission is foot-operated by the gear shifter lever, which transmits the force through a gear shifter shaft. The shifter shaft actuates a pawl and a shifter fork drum. The shifter fork drum moves shifter forks. The shifter forks slide a series of shifter dogs into and out of mesh with the other gears.
Figure 5-44. Transmission power flow: 1. Mainshaft; 2. Countershaft; 3. Countershaft gears; 4. Sliding member; 5. Power flow; 6. Moves in; 7. Moves out