When a car makes a left turn, the left side wheels naturally turn slower than the outside wheels on the right because the exterior wheels have to travel farther than the inside wheels make the turn. For this reason, tires have to be able to move independently and at different speeds to avoid slipping. This gives the car more power and control in the turn.
A differential is a mechanical set of simple gears that allow the wheels to rotate at independent speeds, and to be powered separated by the engine through the drivetrain.
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Front and Rear Differential
Whether your vehicle has one or two differentials all depends on how your wheels are powered. If you have rear-wheel drive, your vehicle uses engine power to move only the rear wheels, so you will only have one differential on the rear axle. If you have an all-wheel or four-wheel drive, your vehicle engine sends power to all four wheels. So you will have front and rear differentials. If you have a front-wheel drive vehicle, you won't find a differential, but instead, you'll have a transaxle that functions like the transmission and a differential. …show more content…
These gears all depend on each other as well as a lubricant (differential fluid) to help it transfer power smoothly and easily. Every kind of differential -- front, rear, and limited slip differential -- all need gear oil to keep the differential drive components from overheating or grinding together.
Differential Problems and Warning Signs
If one of the bearings starts to loosen in your differential or if the differential fluid is thinning and your metal parts start wearing out, you may experience these symptoms:
A whirring sound while decelerating or at speeds over 15 mph
A rumbling noise when the car is going faster than 15