The bolt marked K 28034 is a specially engineered fastener designed for securing the main rocker arm (K 28005) in the ZV40/48 engine. This bolt must withstand dynamic mechanical loads, thermal fluctuations, and vibrations encountered during valve operation. Manufactured from high-strength alloy steel and precision-machined for perfect fit and tension, it plays a vital role in ensuring stable rocker arm performance. Its reliability is crucial for maintaining accurate valve timing and reducing mechanical stress on the valvetrain.