Abstract: A drivetrain assembly for a motor vehicle including a venting system. The drivetrain assembly includes an output shaft from a vehicle prime moreover component such as a transmission or transaxle. The output shaft is coupled to a propeller shaft through a constant velocity joint (CVJ) assembly. A flexible sealing boot encloses the CVJ between the output shaft and the propeller shaft. Internal components of the CVJ are vented by a first longitudinal passageway exposed to the internal volume of the CVJ extending longitudinally along the output shaft. A second radial passageway joins the longitudinal passageway and extends to the radially outer surface of the output shaft forming a second aperture. The passageways combine to provide pressure equalization between the CVJ internal volume and the atmosphere. An optional semi-permeable membrane may be mounted at the second aperture.