What is the procedure for checking dry lifter clearance?

What is the procedure for checking dry lifter clearance?

• A. Collapse the hydraulic lifter, and measure the clearance between the rocker arm and the valve stem with the tappet on the base circle of the cam.
• B. Extend the hydraulic lifter and measure the clearance between the rocker arm and the valve stem with the tappet on the peak of the cam.
• C. Collapse the hydraulic lifter and measure the clearance with a caliper across the lifter body.
• D. Remove the lifter and measure the diameter of the lifter.

Answer: (A)

Dry lifter clearance is measured with the lifter fully collapsed so no hydraulic pre-load affects the gap. Collapse the lifter and place a feeler gauge between the rocker arm and the valve stem while the cam lobe is on the base circle (no lift). This position ensures you’re reading the actual valve lash in a static, dry condition, which is what the check is about. Extending the lifter or measuring at the cam peak would introduce hydraulic pre-load or actual valve motion, giving an inaccurate dry clearance. Measuring across the lifter body or removing it only tells you about the lifter itself, not the rocker-to-valve clearance.

Dry lifter clearance is measured with the lifter fully collapsed so no hydraulic pre-load affects the gap. Collapse the lifter and place a feeler gauge between the rocker arm and the valve stem while the cam lobe is on the base circle (no lift). This position ensures you’re reading the actual valve lash in a static, dry condition, which is what the check is about. Extending the lifter or measuring at the cam peak would introduce hydraulic pre-load or actual valve motion, giving an inaccurate dry clearance. Measuring across the lifter body or removing it only tells you about the lifter itself, not the rocker-to-valve clearance.