Increase the thickness of the ___________ if the valve lash is too large.

• A. Pushrod
• B. Cam Lobe
• C. Rocker Arm
• D. Bucket

Answer: (D)

The amount of valve lash is set by the height of the bucket tappet in a bucket-type valve train. If the lash is too large, you increase the bucket’s thickness to take up the clearance. That extra thickness reduces the gap between the cam, bucket, and valve train, bringing the valve timing back into the desired range.

Other parts don’t directly fix lash in this setup: changing the pushrod length affects overall geometry and timing in other designs, the cam lobe isn’t something you adjust by thickness, and the rocker arm’s dimensions aren’t the lever you use to correct lash when a bucket tappet is used. In a bucket-tappet system, increasing the bucket thickness is the correct way to reduce excessive lash.