The article describes a test rig built at the Department of Vehicles and Fundamentals of Machine Design, Lodz University of Technology (TUL), for static and dynamic examination of vehicle and machinery driveline components. Adequate installed power of the propulsion system and extensive instrumentation of the test rig makes it possible to examine various prototype mechanical transmission units with power capacities of up to several ten kilowatts and to carry out a broad spectrum of measurements with high accuracy. During the tests, such variables as vibrations in any direction, gear shaft speeds, torques, noise levels, and various oil parameters, e.g. temperature, moisture content, or ferromagnetic debris content, may be recorded. Additional equipment enables precise alignment of all the rotating parts in the test rig drive train and determination of oil viscosity before and after the test. An important feature of the test rig is a possibility of changing the drive direction without demounting the object under test. This can be done thanks to an inverter control system, which enables electric machine operation modes to be switched over from motor to generator and vice versa. In the subsequent part of the article, selected results of testing a planetary gear unit with a geometric gear ratio of 3.1372 have been presented, which include efficiency, FFT analysis of vibrations, and noise level data. The test results have confirmed the suitability of the test rig for multipurpose applications and for comprehensive diagnosing of driveline components.