Drivetrain.

The drivetrain serves two functions: it transfers power evenly from the engine to all drive wheels and it varies the amount of torque. The drivetrain may include the differential, a transfer case (in four-wheel and all-wheel drive cars) and the transmission.

Differential Service

The differential is a special gear box located between the drive wheels of your vehicle. It allows the drive wheels to turn at different speeds, as they must when turning a corner. Over time, high operating temperatures can cause the lubricating fluid in the differential to break down, developing a gummy texture that doesn’t properly lubricate the gears. Replacing the fluid can help you avoid premature wear on the gears in the differential, and can even help reduce wear on drive-wheel tires.

Transfer Case Service

The transfer case is a special gear box found in four-wheel and all-wheel-drive vehicles. It sends drive power from the engine to the front and rear axles. In all-wheel-drive vehicles, the transfer case helps to shift power from one axle to another, depending upon traction conditions. Lubricant fluid in the transfer case helps to keep its gears cool and turning smoothly. Replacing this fluid at appropriate intervals can help prevent premature wear and damage caused by contaminated or broken-down lubricant.