Which instrument is commonly used to verify crankshaft end play?

Which instrument is commonly used to verify crankshaft end play?

• A. Dial indicator
• B. Vernier caliper
• C. Calibrated scale
• D. Ruler

Answer: (A)

Measuring crankshaft end play requires sensing very small movement along the crank’s axis. The dial indicator is designed for exactly that: it converts tiny linear displacements into a readable rotation on its dial, giving you a precise measurement in thousandths of an inch. To verify end play, you set the indicator so its probe bears on a thrust surface of the crankshaft, then zero it with the crank in a neutral position. Gently move the crankaxially (back and forth) and read the dial. The total travel shown equals the end play. This high sensitivity is what makes the dial indicator the right tool for this task. Vernier calipers measure external dimensions and are not capable of reliably detecting the small axial movement involved in end play. A calibrated scale or a ruler lacks the precision and setup flexibility needed for such a measurement.

Measuring crankshaft end play requires sensing very small movement along the crank’s axis. The dial indicator is designed for exactly that: it converts tiny linear displacements into a readable rotation on its dial, giving you a precise measurement in thousandths of an inch.

To verify end play, you set the indicator so its probe bears on a thrust surface of the crankshaft, then zero it with the crank in a neutral position. Gently move the crankaxially (back and forth) and read the dial. The total travel shown equals the end play. This high sensitivity is what makes the dial indicator the right tool for this task.

Vernier calipers measure external dimensions and are not capable of reliably detecting the small axial movement involved in end play. A calibrated scale or a ruler lacks the precision and setup flexibility needed for such a measurement.