Which tool is used to check flywheel face runout?

• A. Caliper
• B. Dial indicator
• C. Feeler gauge
• D. Torque wrench

Answer: (B)

Measuring flywheel face runout requires sensing tiny lateral movement of the surface as the wheel turns. A dial indicator is ideal because it provides a high-sensitivity readout in thousandths of an inch, and, when mounted on a stable base, you can zero it on a reference point and then rotate the crank to see how much the surface deviates from true. The indicator’s needle movement directly shows the amount of runout, giving a precise measurement of how much the flywheel face is out of plane. Calipers measure dimensions at a single static point and won’t capture the variation as the surface spins; a feeler gauge measures gaps at a specific location and doesn’t track continuous surface deviation; a torque wrench is for applying a specific torque, not for measuring runout. So the dial indicator best fits the need to quantify flywheel face runout.