As any automotive trainee soon learns, a car’s differential must provide torque to propel the vehicle, even when the wheels and axles are turning at different speeds. Various differential designs are used to accomplish this and other functions in rear-wheel drive, front-wheel drive, and all-wheel drive vehicles. This video guides students through various differential and drive designs and summarizes how each one operates. Viewers are shown the basic workings of an enclosed drive shaft and of a solid rear-axle assembly, and how either solid or flexible drive axles link the differential to the drive wheels. Subsequent chapters shed light on ring and pinion gears, open differentials (including the set of spider gears mounted inside the carrier), limited slip or positraction differentials, Torsen-Gleason differentials using worm gears to produce a no-slip drive setup, and computer-controlled electric clutch differentials. Various all-wheel drive designs are also discussed. A viewable/printable instructor’s guide is available online. A Shopware Production. A part of the series Powertrain Technology and Service. (18 minutes)