A drivetrain test fixture was developed to evaluate the steady-state, light-load efficiencies and spin losses of various types of all wheel drive systems. Additionally, frictional torque biasing effects on open differentials were studied. All drivetrain components, less the engine and wheel bearings were connected to a five-dynamometer test fixture, mounted .on a bed plate. A computerized acquisition system was used to gather all test data. Test procedures and data analysis are presented.