421GC314M
Engine Rocker Arm Adjusting Screw
Mack

This adjusting screw is a key component in the valve train assembly, allowing precise control of rocker arm positioning. Proper adjustment of the rocker arm ensures optimal valve timing and engine performance, which directly impacts power output and fuel efficiency. Made from high-strength materials, it resists wear and maintains its integrity under high-stress conditions typical of heavy-duty engines. Accurate adjustment with this screw helps prevent valve train noise, uneven wear, and potential engine damage. Regular maintenance and correct installation are essential for maintaining engine reliability. Source One Parts Center offers this part as part of a comprehensive engine repair kit, supporting the longevity and efficiency of your heavy-duty powertrain.