The differential is the component that allows rotating power from the engine to be transferred to the moving wheels. The differential allows each wheel to rotate at different speeds while turning and cornering. In front wheel drive vehicles, the differential is in the front and called a transaxle. In rear-wheel drive vehicles, the differential is in the back. Four wheel drive vehicles have differentials in both the front and back. The differential contains fluid that lubricates and cools the gears. Consider getting your front or rear differential fluid checked when you drive under the following conditions: Frequently towing a boat or RV; Driving in severe conditions; Driving in rough and wet terrain. At Quality Transmission, the certified mechanics do drive train repairs. They service front and rear differentials.