Drivetrain

On an automobile, the drivetrain is responsible for transferring the power produced by the engine to the vehicle's wheels. While a car's engine is normally the star of the show, the drivetrain is equally as important to a successful road-going journey. For more information on the various parts that make up the drivetrain and the different configurations that are currently used on the road, keep reading below.

The transmission can be considered the beginning of the drivetrain. Transmissions take power produced by the engine and direct it through a series of gears to create torque. When you open a jar, you are applying torque to turn the lid of the jar, just as when torque is produced by an engine, the wheels will turn and the car will move. From the transmission, power moves to a component called the differential. A differential is necessary because, as a vehicle goes around a corner, the wheel closer to the inside of the turn must travel at a different speed than the wheel on the outside. The inside wheel technically has to travel a shorter distance, so the outer must move more quickly to make up the difference.

Transmissions and differentials can be found in every car, but there are a variety of configurations that effect how the engine's power will ultimately reach the ground. Here are some of the most common configurations:

Front Wheel Drive: In a front wheel drive car, the transmission directs the engine's power to the front wheels. In these designs, the differential is usually incorporated into the transmission, making them one unit. A majority of newer cars are front wheel drive, as it is an easy setup for the average driver because the vehicle is less likely to lose control if the throttle is used too aggressively.

Rear wheel Drive: Rear wheel drive cars use a driveshaft (connected to the transmission) to send power to the back wheels. In this type of car, the differential is usually located in the back of the car between the wheels. In this configuration, the front wheels receive no power and are used solely for steering.

Four-Wheel Drive and All-Wheel Drive: A common all or four-wheel drive setup uses a transmission similar to what is found in a front wheel or rear drive car. One additional component in this system is called a transfer case. In a four-wheel drive truck, the transfer case will essentially force the front wheels to spin along with the rear. This greatly enhances traction on slippery surfaces. It is, however, different from an all-wheel drive configuration.

An all-wheel drive system will allow all four wheels to spin at different speed. They usually require no driver interaction. Some electronic all-wheel drive systems will only activate when the onboard all-wheel drive computer detects a wheel slipping. In these systems, all the traditional all-wheel drive components are present, but may only work when they are needed. In a full time all-wheel drive system all four wheels receive engine power all the time. Usually, these systems will feature less electronic intervention than their part-time counterparts.

Maintenance schedules for each configuration vary, and the best way to assure a worry free service life is to follow the instructions provided by your vehicle's manufacturer. Those looking for a new car should keep in mind that each type of drivetrain has a very different purpose and feel. Prospective buyers are advised to try each layout to determine their own personal preference before making their final purchase. Click here for more information on other types of performance parts.