Visually check the camshaft bearing surfaces for pitting, score marks, galling, and abnormal wear; if damaged, the
Cylinder Head must be replaced. Measure the outside diameter of each camshaft bearing journal and record the measurements, then measure the inside diameter of each corresponding camshaft bearing. Subtract each cam journal outside diameter from its respective cam bearing bore inside diameter to determine the oil clearance for each bearing and compare the results to the specified journal-to-bearing clearance; if any measurements fall outside the standard wear limits, either the camshaft or the cylinder head, or both, must be replaced. Check camshaft runout by placing the camshaft between two V-blocks or back into the cylinder head, setting up a dial indicator on the center journal, zeroing it, and turning the camshaft slowly while noting the readings; if the measured runout exceeds the specified limit, replace the camshaft. Measure each cam lobe height with a micrometer, compare it to the specified height, and compute wear by subtracting the measured height from the specified height; if the wear exceeds the limit, replace the camshaft. Inspect the contact and sliding surfaces of each Lash Adjuster for wear and scratches, noting that if the Lash Adjuster pad is worn, the corresponding camshaft lobe or adjusting shim should also be checked. On SOHC engines, do not lay the Lash Adjusters on their side or upside down to avoid trapping air; they can only be laid on their side if submerged in clean engine oil until reassembly. Measure the outside diameter of each Lash Adjuster with a micrometer and compare it to the specifications; replace any Lash Adjuster worn beyond the limit. Check each Lash Adjuster bore diameter and compare the results to the specifications; if any bore is worn beyond the limit, the Lash Adjuster guide assembly or the cylinder head must be replaced. Subtract the outside diameter of each Lash Adjuster from the inside diameter of the Lash Adjuster bore and compare the difference to the specified clearance; if both the Lash Adjuster and bore are within acceptable limits, this measurement should also fall within tolerance, but new parts may affect this. On SOHC engines, inspect the rocker arms and shafts; if the pads are worn, replace the rocker arms without attempting to restore them by grinding. Ensure all parts, whether new or old, have been thoroughly inspected before reassembly.