The transfer case is used in 4 wheel and all wheel drive systems. The transfer case directs power to the front and rear axles through two separate drive shafts. Power from the engine travels through transmission system and then is distributed to front and rear wheels through their respective axles. It consists of the engine, clutch, gearbox It has two output shafts facing in opposite directions. The rear one drives the rear wheels and front one, the front wheels. When 4X4 transmission is selected, a shift dog moves an idler gear rearward and engages the two shafts together resulting in transmitting power to all four wheels.