A gas shock absorber has a pressure tube which defines a working chamber. A piston
assembly divides the working chamber into an upper working chamber and a lower
working chamber. A plurality of extension passages extend through the piston assembly
and are opened and closed by an extension valve assembly. A plurality of compression
passages extend through the piston assembly and are opened and closed by a compression
valve assembly. A rod guide assembly is located between the pressure tube and the
piston rod. The rod guide assembly includes an oil chamber for sealing and lubricating
the piston rod. An axially movable piston maintains the pressure within the oil
chamber equal to the pressure in the upper working chamber.