Ensure peak performance and long-term reliability for your diesel engine with the Genuine Cummins Rocker Lever Adjusting Screw (SKU: 3964720). This precision-engineered component is critical for maintaining accurate valve lash settings within the overhead assembly. By providing a stable and adjustable interface between the rocker arm and the valve stem, this screw ensures your engine operates with optimal timing, maximizing fuel efficiency and preventing unnecessary wear on internal valvetrain components. Manufactured to Cummins’ rigorous OEM specifications, the 3964720 adjusting screw is crafted from high-grade, heat-treated steel designed to withstand the extreme pressures and thermal cycles of heavy-duty operation. Unlike aftermarket alternatives, this genuine part offers superior thread integrity and a hardened contact surface, reducing the risk of loosening or premature pitting that can lead to costly engine noise and power loss. Whether you are performing a routine overhead adjustment or a complete engine overhaul, using authentic Cummins hardware guarantees a perfect fit and seamless integration with your existing rocker lever assembly. This part is compatible with a wide range of Cummins B-Series and ISB engines commonly found in automotive, industrial, and marine applications. Invest in the durability of your powertrain and maintain your engine’s factory performance standards with this essential adjustment screw.