Abstract: A transfer case for four wheel drive vehicles having a housing made up of two identical, complementary castings. The castings are secured together in opposed, complementary relationship to define a compartment for the mechanism for transmitting power to the front and rear axles of the vehicle. The castings are of identical construction to provide a compact housing and reduced manufacturing costs because of the interchangeability of the two castings making up the housing. The castings are formed to support a variety of transmission mechanisms. In one such arrangement disclosed, a dual range transmission is provided including parallel chain and gear train transmissions from the power shaft to the output shafts to the front and rear axles of the vehicle. The opposed end walls of the housing defined by the two complementary castings are formed with supporting structure for the power shaft from the engine, a counter shaft for the gear train transmission, and the output shafts for driving the front and rear axles.