<P> Automobile drivetrains generally have two or more major areas where gearing is used . Gearing is employed in the transmission , which contains a number of different sets of gears that can be changed to allow a wide range of vehicle speeds , and also in the differential , which contains the final drive to provide further speed reduction at the wheels . In addition , the differential contains further gearing that splits torque equally between the two wheels while permitting them to have different speeds when travelling in a curved path . The transmission and final drive might be separate and connected by a driveshaft , or they might be combined into one unit called a transaxle . The gear ratios in transmission and final drive are important because different gear ratios will change the characteristics of a vehicle 's performance . </P>
where is a simple gear train used in real life
Automobile drivetrains