Check the condition of the bearing journals and cams. If the inspection reveals wear on the journals and cams, replace the camshaft. At considerable wear of necks replace also a head of cylinders. If the condition of the journals and cams is satisfactory, then check the wear of the cams with a micrometer, runout (in the central neck) and deformation of the camshaft by laying the camshaft on prisms and installing a rod with an indicator (photo). If the runout exceeds 0.025 mm, replace the camshaft. Determine the height of the cam as the difference in dimensions in directions B and A (photo). If the height of the cams for the intake and exhaust valves is different, then replace the camshaft.