If valve lash is too large, which part's thickness should be increased?

• A. Rocker Arm
• B. Cam Gear
• C. Bucket
• D. Valve Stem

Answer: (C)

Valves have a small clearance, or lash, between the valve stem and the rocker arm tip. In a bucket-tappet configuration, the bucket’s thickness sets how high the rocker arm sits relative to the valve stem, so it directly controls that gap. If lash is too large, increasing the bucket thickness raises the rocker and reduces the gap, bringing the valve into the proper position to seal and actuate cleanly. The other parts don’t typically adjust this clearance: the cam gear governs timing, the valve stem thickness is fixed by design, and changing the rocker arm geometry is not a standard way to correct lash. So, increasing the bucket thickness is the correct way to compensate for excessive valve lash.