Abstract: A telescoping drive shaft comprising a first drive shaft element which telescopingly receives a second drive shaft element which is provided with lubricating passages. Lubricating grease held in the first drive shaft element can be directed through the lubricating passages to the intermeshed splines of the two drive shaft elements. A non-positive seal at the end of the first drive shaft element is used to exhaust excess lubricating grease from the drive shaft.

Abstract: A park brake mechanism includes a sealed housing enclosing a brake disc pack which is normally pressed together by a plurality of coil compression springs acting between an end of the housing and a pressure plate. Four hydraulic pistons are reciprocably mounted in the opposite end of the housing and connecting pins are received between the pistons and the pressure plate and serve to effect the release of the braking action between the disc pack discs when the pistons are pressurized. The pistons are in a rectangular pattern and diagonally opposite ones have threaded ports aligned therewith and adapted for receiving screws for stroking the pistons in the absence of pressure. A fluid pressure passage leading to the pistons contains a one-way orifice which operates to modulate the application of the brakes when pressure is relieved from the pistons.