How Does a Manual Transmission Work?
2 Answers
Manual transmission works by: engaging the gear, changing the input shaft, transmitting through the countershaft, and finally outputting to the differential via the output shaft. When the differential moves, the tires move accordingly. In other words, by using the shift fork to change the gear ratio of the meshing gears, the driving torque is altered. The speed of the gears is inversely proportional to the number of teeth on the gears, meaning gears with more teeth rotate slower. By combining a series of gears of different sizes, different gear ratios can be achieved. The transmission consists of various gears and shafts, with gears being the core component of the transmission. All gears can be collectively referred to as the gear set. Typically, there are three shafts inside the transmission: the input shaft, the output shaft, and a countershaft.
I've been in auto repair for over a decade. A manual transmission essentially relies on gear meshing to transmit power. When you press the clutch pedal, the pressure plate releases the friction disc, cutting off the engine's power. Only then can you shift the gear lever, which is connected to the shift fork inside the transmission. The fork pushes the synchronizer, which brings the gears closer together, meshing different-sized gears on the input and output shafts. Lower gears have a greater difference in gear size, providing more torque but lower speed. Higher gears work the opposite way. Releasing the clutch gradually presses the friction disc against the flywheel, restoring power like reconnecting a water pipe. The synchronizer is crucial in this process—it must match the speeds of the two gears before they engage with a click, otherwise, gear grinding is inevitable.
