A rocker arm is a valvetrain part that transmits the motion of a pushrod to the exhaust valve. They are usually made from materials such as stamped steel or aluminum.
Rocker arm importanceRocker arms include a bearing which is important to lessen the wear and friction at the point of contact. The rocker arm rotates due to the top of the pushrod pressing against one side of the rocker arm. The rotation causes the other end of the rocker arm to come into contact with the top part of the valve, which opens the valve. Also, the roller tip can lessen the friction when contact is made with the valve stem.
Common issues with a faulty rocker armA faulty rocker arm can lead to uncommon noises, stalling, and a cracked rocker arm.