TRANSMISSION AND DRIVE
A car's transmission is connected to the engine so the transmission can receive power directly from the engine. The arrangement of the engine and transmission depends upon the kind of drive the car has.
Most cars have front-wheel drive. This means that the front pair of wheels moves the car. Other cars have rear-wheel drive. Another kind of drive is four-wheel drive. In a part-time four-wheel drive, the drive train can be controlled to provide power at either two or four wheels. In an all-wheel drive, power is always available at all four wheels.
In the most common arrangement, the engine and transmission are mounted transversely (across the car) between the front wheels. In this arrangement, the transmission is a part of a unit called a transaxle. This unit also includes another device that adjusts speed and torque--a final drive and differential. The transaxle drives the front wheels.
Most cars built until the early 1980's had rear-wheel drive, with the engine and transmission mounted in front. A rotating cylindrical tube called a drive shaft delivered power from the transmission to a final drive and differential in the rear of the car.
