Word forms: (regular plural) rocker arms
noun (Automotive engineering: Vehicle components, Engine, transmission, and exhaust) A rocker arm is a centrally pivoted lever in the valve train of an engine that converts the motion of the rods to open the valves. ⇒ Rocker arms transmit motion from the cam lobes to the valves. ⇒ One end of each rocker arm carries an adjusting screw with a cap or cup which is in contact with the push rod. ⇒ Push rods are designed to be the connecting link between the rocker arm and the valve lifter.
Collins English Dictionary. Copyright © Harper Collins Publishers