Abstract: Helical spring is mounted between two lever arms which are hinged together at one end; the spring is attached at its ends to disks which are pivoted rotatably to the lever arms, the spring axis being parallel but eccentric to the line joining the two pivot points. Rotation of the disks moves the spring closer to or farther from the hinge point, effectively changing the elastic constant between the distal ends of the lever arms, which are points of attachment to a vehicle chassis and to its running gear, respectively. Spring position may be adjusted by worm drive operated manually by crank or by motor controllable by driver from instrument panel; this adjusts vehicle springing to various vehicle loads.