What component do manual transmissions/transaxles primarily use?

Manual transmissions and transaxles primarily use a clutch as a key component for their operation. The clutch serves as a crucial interface between the engine and the transmission, allowing the driver to engage or disengage the engine's power from the wheels. When the driver presses down on the clutch pedal, it disengages the clutch plate from the flywheel, enabling gear changes without stalling the engine. This mechanism is essential for smoothly shifting gears, as it allows the driver to select different gear ratios while the vehicle is in motion.

While other components mentioned, such as pumps, belts, and filters, are integral to other types of mechanical systems or automatic transmissions, they do not play the same role in manual transmissions. Pumps are typically associated with hydraulic systems, belts are found in various drive systems, and filters are used to ensure fluid cleanliness but do not directly engage in the operation of gear selection in manual transmissions.