The D.E.P. Academy Driver Education Course


Vehicle Systems And Maintenance Page 1

The Vehicle Frame And Body

  • The purpose of a vehicle's frame is to support the body, engine, and other parts of the car . The frame of the vehicle is one of the most important parts of the car. It is the back bone of the automobile. It provides structural integrity for the whole car.
  • The frame itself is held up by the tires and the suspension support system, which is what allows cars to handle curves, pot holes, and uneven sections of the road.

Vehicle, Engine, and Mechanical Systems

  • When You Start Your Car power from the battery is used to operate the starter motor so that it can turn the fly wheel and the crank shaft. The crank shaft is an internal part of the engine which supplies power to the rest of the drive train. The crank shaft is also connected to the piston rods, which are inside the engine cylinders. A combination of air and fuel is compressed to create an implosion, pushing the pistons up and down. The fuel and air mixture is delivered by a carburetor and manifold, or fuel injection system, and then the spark plug ignites the mixture.
  • All moving parts of the engine must be lubricated with the proper motor oil, such as 5-W-30, 10-W-30,10-w-40, or synthetic motor oil. The oil will accumulates at the bottom of the engine, where the oil pump pushes the oil thru an oil filter, then channels it thru the parts of the engine that need to be lubricated.

The Fuel System

  • The Gas Tank is the storage unit where the fuel is kept. It is then pumped through the fuel lines by a mechanical or electronic pump. It then travels thru the fuel filter to the carburetor, or E. F. I.  (Electronic Fuel Injection).

The Power Train

  • The Tower Train is a combination of mechanical components that transfer power to the wheels.

These are the components;

  • Engine or Motor The internal combustion engine is a machine that converts heat energy derived from fuel into mechanical energy.
  • Transmission The speed and power changing device in the power train that provides different gear ratios between the engine and the drive wheels, plus a reverse gear for backing up the car .The transmission multiplies engine torque when the car is accelerated from a stop or is climbing a hill. When cruising on a relatively level road surface it trades torque power for higher wheel speeds and a reduction in engine speed.
  • Differential A gear system that transfers power from a driveshaft, or transmission, to the driving axle or half shaft. It permits the outer driving wheel to turn faster than the inside wheel when the car is turning. This helps to prevent skidding and tire scrub.
  • Four-Wheel Drive In four wheel drive vehicles the power is transmitted to the transfer case by the transmission. The transfer case shifts power to the rear wheels, the front wheels, or both front and rear wheels.
  • Front Wheel Drive In front wheel drive vehicles the power is transmitted from the engine thru a combination transmission-differential, and then the power is directed to the front wheels.
  • Driveshaft In a rear wheel-drive, or four wheel-drive vehicle, the driveshaft is a long hollow shaft, with universal joints at both ends, that carries power from the transmission to the differential. It runs along the cars longitudinal centerline. Also called a propeller shaft or prop shaft.
  • Wheels The wheel is the circular, rigid metal frame consisting of a center section and a rim that connects the hub of a vehicle to a tire in a fixed but not permanent way.
  • The Tires A rubber covering fitted to a wheel usually containing compressed air to support a vehicle's load .The acceleration , braking , and cornering forces acting on a vehicle are resisted by the tires. you should all ways rotate your tires and maintain tire inflation.

Check your vehicle's manual, or with your local tire dealer, for specific tires for your vehicle.

The Exhaust System

  • The Exhaust System was developed for the reduction of noise that an engine produces. It is also used to control harmful emissions (smog) produced by cars. Some of the more important components are the muffler (muffles sound) and the catalytic converter (helps eliminate smog).
  • The Manifold is an assembly of tubes, usually made of cast iron, that are attached to the engine's cylinder head and provide paths through which burned gases can flow thru the exhaust system.
  • The Catalytic Converter is an emissions control device in the exhaust system, usually containing platinum or palladium, that is a catalyst for the chemical reaction that converts unburned hydrocarbons and carbon monoxide into water, vapor, or carbon dioxide, and other hot gases less toxic than untreated exhaust.
  • The muffler, a chamber attached to an engine's exhaust pipe and fitted with baffles or porous plates, reduces or muffles the noise created by the exhaust.

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