An essential mechanism: the differential

A differential is a mechanism that controls your car’s drive wheels and driveshaft. It’s one of the most important components in your car’s engine and performs three key functions:

• It sends power from the engine to the car’s wheels
• It slows down the transmission’s speed before the power reaches the wheels
• It divides the power from the engine so the car’s wheels can spin at different speeds

A conventional differential is made up of two satellite gears attached to two planetary gears, all of which are joined to a crown wheel. As the engine powers the driveshaft, it causes the crown wheel to rotate, which in turn, transmits power to the satellite and planetary gears and allows the car’s wheels to rotate at different speeds.

When you make a left turn, the right wheels on your car have to travel farther than those on the left. The differential’s gearing system automatically sends more power to the wheels with less traction, i.e., the right wheels, so that your turn is as stable as possible.

Four-wheel drive vehicles have three differentials. There’s one for each pair of wheels and another that separates the front wheels from the rear wheels. This allows the vehicle to travel over uneven terrain. A faulty or worn-out differential can cause handling issues and lead to dangerous skidding. Visit your nearest Mr. Muffler to find out when you should have yours inspected.