Hydraulic stabilizer for axle on mast lift vehicle

A stabilizer on a lift vehicle comprising, a vehicle having a lift mast, a lift carriage reciprocally mounted on said mast for carrying a load, a vehicle chassis, a pivotal axle pivotally supporting said vehicle chassis, a pair of hydraulic cylinders with each cylinder pivotally connected to said axle and to said chassis on opposing sides of said chassis, a hydraulic stabilizer circuit circulating hydraulic fluid in one cylinder and out the other cylinder of said hydraulic cylinders to allow pivoting of said axle, a normally open control valve between said hydraulic cylinders controlling the flow of hydraulic fluid in and out of said hydraulic cylinders, pressure relief valves for cross-over flow between said hydraulic cylinders controlling predetermined stabilizing forces, said control valve closing and interrupting flow in and out of said hydraulic cylinders responsive to the lift of the carriage on said mast lifting above a predetermined height thereby locking said hydraulic cylinders and rigidly fixing said axle with said chassis for stabilizing the support for said vehicle chassis.