A shock absorbing mechanism has a fluid filled pressure chamber with a piston mounted therein along with a restrictive orifice leading to an outer chamber. When shock is transmitted by the piston, fluid is forced through the opening against compressed gas contained in the outer chamber. The opening is formed in a movably mounted valve element normally biased against a valve seat but which is forced away from the valve seat by the fluid which had previously passed through the orifice after the force caused by the shock is abated. The size of the orifice in the valve element is controlled by a thermostatic coil mounted on the valve element. The coil is connected to a pin which pivots as the coil expands or contracts due to changes in temperature causing a flag mounted on the pin to slide over the surface of the valve element in which the orifice is formed.