Check the condition of the bearing journals and cams. If inspection reveals wear on the journals and cams, replace the camshaft. If the journals are significantly worn, also replace the cylinder head. 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 camshaft deformation by placing the camshaft on prisms and installing a rod with an indicator (photo). If the runout exceeds 0.025 mm, replace the camshaft. Determine the cam height as the difference in dimensions in directions B and A (photo). If the cam heights for the intake and exhaust valves differ, replace the camshaft.