Many cars come equipped with a four-wheel or all-wheel drive system. These kinds of systems operate with the help of a transfer case, or device that connects the transmission to other car components.
Transfer cases receive power generated by the transmission and send that power to the front and rear axles via a drive shaft. Transfer cases can transmit this power via a set of gears. However, most modern transfer cases are chain driven.
Vehicle operators can control function of the transfer case via a shifter, or gear stick lever. This lever enables the driver to put the transfer case into two-wheel drive or four-wheel drive. Some vehicles use an electronic switch as opposed to a shifter.
Transfer cases often contain at least one set of low-range gears. These gears are operated by a shifter or switch, and are designed to increase torque, or the force of motion, to the axles while slowing down the vehicle. Low-range gears are typically used for such functions as load-pulling and rock crawling, or off-road driving over harsh or elevated terrain.
