Generally speaking, there are four systems in the chassis, which are transmission system, traveling system, steering system and brake system.

Transmission system (see fig 11-2) is located between the engine and driving wheel. The function of the transmission system is to transmit the power from the engine to the driving wheel. The main components of transmission system are clutch, gearbox, final reduction and differential. The purpose of clutch is to permit the driver to couple or uncouple the engine and transmission. And it is the gearbox that provides different gear ratios between the engine and wheels. The function of the differential is to permit the right and left wheel to rotate at different speed when the car goes around a turn.

Traveling system (see Fig 11-3) consists of frame, axle, wheel and suspension. The frame is the foundation of the whole vehicle. Axles are connected to the frame by springs to even out the shocks from the irregularities of the ground surface. It is suspension that transfers the forces and torques from the wheel to the frame, absorbing impact and vibration.

We use steering system (see Fig 11-4) to guide the car. That is to say, the purpose of the steering system is guiding the car where the driver wants it to go. The main components of the steering system are as follows.

We use brake system (see Fig 11-5) to slow or stop the car. Good brakes are essential for safety. Hydraulics brakes are usually used on common cars, and it operates by applying pressure to a fluid.