【正文】 ng Engine, which generally organisms, with gas, crank linkage, fuel oil supply systems, cooling systems, ignition systems, launch systems and other ponents. Site to accept the engine driving force, so that a sports car, and to ensure that the driver of the vehicle in accordance with the manipulation of normal traffic.ClutchThe main function of clutch is cut off and realize the transmission of engine power transmission to ensure that when the car started the engine and transmission smooth joint, to ensure a smooth start car in the shift when the engine and transmission of separation, to reduce transmission of the shift Gear between the impact in their work by the larger dynamic load, we can limit transmission of the largest faced by the torque to prevent the transmission of some parts due to the overload and damage to effectively reduce the transmission of noise and vibration .Gear BoxA gear box is a speed and power changing device installed at some point between the engine and driving wheels of the provides a means for changing the ration between engine and driving wheels rpm to best meet each particular driving situation. The gear box is a device that is connected to the back of the engine and sends the power from the engine to the drive wheels. An automobile engine runs at its best at a certain range.Front AxleFront axlw is used for steering front wheels carried on stubaxles swiveling upon king pins at the axle extremities.Seering SystemsSteering arms and a track rod link the two stub axles together for swiveling them by a steering wheel about the king steering wheel linked to one of the stub axles by a shaft,a gear box and a suitable linkage is opeated by the driver’s hand the axlea onepiece beam was used to support the vehicle through springs,An arrangement known ad independent front suspension has replaced the axle and spring the control of springs,the wheels are free to rise and fall vertically independently of each other.Drive AxleFor fixing rear wheels,a tube like shaft enclosing driving shafts with suitable bearings for rotating the wheels is is enlarged at the center for enclosing the final drive gears used for providing main speed reduction between the engine and the driving wheels. The change of direction of the drive trom the fore and aft line of the propeller shaft to the transverse line of the axle shafts is also provided by this tube known as rear axle.The differential is a device that splits the engine torque two ways, allowing each output to spin at a different speed. It is found on all modern cars, and also in many allwheeldrive vehicles. These allwheeldrive vehicles need a differential between each set of drive wheels, and they need one between the front and the back wheels as well, because the front wheels travel a different distance through a turn than the rear wheels. Parttime fourwheeldrive systems don39。t have a differential between the front and rear wheels。 instead, they are locked together so that the front and rear wheels have to turn at the same average speed. This is why these vehicles are hard to turn on concrete when the fourwheeldrive system is engaged.Each wheel is provided with its own separate halfshaft connected by a differential gear and meeting at about the center of the wheels are free to rotate at different speeds although they are provided with equal by the differential gear.Bake SystemFor controlling the movement of the vehicles or to stop them,efficient braking system is a necessity for a attached to each of the four wheels are of two the initial type,a pair of shoes carried on a stationary plate is expanded in contact with a rotating drum mounted on the wheels to arrest the motion of the the modern type of brakes,one or more pairs of pads are carried in a caliper attached to the axle or wheel supporting sides of the disk mounted on the wheel are griped by these applying pressure on a pedal,the brakes are hand lever acting through a separate linkage and locked in the on position is used.For operating the brake,either mechanical or hydraulic system is system requiring gearing system for mechanical and hydraulic fluid for the hydraulic brakes are usedPropeller Shaft And Uniwersal JointFor connecting the output shaft of the gear box to the rear axle,a long shaft known as propeller shaft is shaft is either enclosed in a tubular casing or kept exposed or opened with a universal joint fitted at each end for allowing the changes in the shaft alignment with the rise and fall of the rear axle due to road surface joints cannot be eliminated even if the final drive gears are fixed to the frame with the wheel springing the misalignment resulting from the flexing of the vehicle structure over bumpy road surfaces can be avoided nor the precise alingnment of shaft can be ensured without them.For preventing the transmission of shock from uneven road surfaces to the vehicle,springs are used to support the vehicle on the axle.In order to allow for the vertical movements of the wheels relative to the frame as well as to allow the parts of the shaft to operate at different angle,another increasingly used arrangement is consists of mounting the finaldrive gears and the differential gear in a casing attached to the frame with independently sprung wheels attached to them by means of shafts through devices called universal joints.WheelsThe wheels which are four in number are fitted below the car chassis to support the load of the vehicle and passengers as well as to run the arefitted with hollow rubber tyres filled with air in rubber tubes under sufficient pressure necessary for carrying the caused by road irregularities are absorbed by fitting springs between the wheels and the vehicle allowing the vertical movement of wheels in relation to vehicle,greater part of unevenness of road surfaces is taken care of.When going round a curve,the inner wheel has to travel a smaller distance in parison to th