In a manual-transmission vehicle, the flywheel is attached to the engine’s crankshaft.
The crankshaft converts the pistons’ up-and-down motion into rotation, and the flywheel is bolted to one end of it. As a result, the flywheel spins at engine speed. Its rotational inertia helps smooth the uneven pulses produced by individual combustion events, especially at low engine speeds.
The flywheel also forms one side of the manual clutch assembly. When the clutch pedal is released, the clutch disc is clamped between the flywheel and pressure plate, transferring torque to the transmission input shaft. Pressing the pedal removes that clamping force so the engine and gearbox can temporarily rotate independently.
The driveshaft and half-shafts are downstream components: they carry power from the transmission toward the wheels. The camshaft belongs to the engine’s valve train and controls valve timing, but it does not carry the flywheel. Automatic vehicles typically use a flexplate and torque converter instead of a manual-transmission flywheel and friction clutch arrangement.