Abstract: A rectangular metering member with transversal grooves is located with respect to specially formed apertures in a pressure tube of a hydraulic shock absorber to form orifices communicating between the shock absorber pressure tube and a reservoir. The orifices are adjusted in size automatically to account for hydraulic fluid viscosity changes as a function of temperature by a thermal expansion plug which moves the metering member to increase or decrease the size of the orifices. The metering member is also manually positionable to adjust the size of the orifices for loads of varying mass and velocity. The specially formed apertures in the pressure tube allow the automatic temperature compensation to operate independently of the initial manual adjustment of the metering member.