Which instrument is used to check the face out of the Flywheel?

A dial indicator is commonly used to check the face runout of a flywheel. This precision instrument measures the slight variations in the surface of the flywheel as it rotates, allowing for the identification of any misalignment or irregularities. By attaching the dial indicator to a fixed point and probing the flywheel's surface, technicians can assess its accuracy and ensure proper functioning.