To extract the camshaft, loosen off the primary and secondary timing chain tensioner (6) bolts first. During engine construction, the camshaft bearing caps are labeled, as the first exhaust camshaft bearing will be written as "1E." Release the camshaft bearing cap bolts one at a time and then take off the cap covers (1). Following that, lift out the intake camshaft (7), exhaust camshaft (2), secondary timing chain (8) and secondary timing chain tensioner (6) all together, then take away the secondary timing chain tensioner (6) and secondary timing chain (8) from the two camshafts (2&7). Check the camshaft bearing journals (2) for any damage and binding and, if binding is found, look for damages and oil hole blockage in the cylinder head. Check whether the camshaft sprockets are worn and change the camshafts if they are. Assess wear and damage on the cam lobe surfaces. If the camshaft is faulty, replace it and if the actual cam wear exceeds 0.0254 mm (0.001 inch) or 0.254 mm (0.010 inch), then put in a new one. Prior to installation, verify that the crankshaft is at the right angle when moving the timing chain to decrease the chance of valve and piston damage. Place the camshaft chain on the cams so the plated links (1) are out front and point to the dots (4) on the sprockets. If the chain tensioner has already been slid in place and is secured, skip to the following procedure. If not, set the tensioner in a soft jaw vise and carefully add the fabricated lock pin through the locking holes, then take it out of the vise. After compression and encasing the camshaft chain tensioner (2), insert it between the camshafts and chain. Rotate the cams so that the plated links (1) and dots (4) reach the 12:00 position. Fit the cams onto the cylinder head so that the rocker arms are organized properly. After putting on the camshaft bearing caps in the original position, tighten the cam bearing cap bolts according to the steps shown, until they reach 12 Nm (105 inch lbs.). Install both tensioner bolts and tighten them to 12 Nm (105 inch lbs.), after which remove the locking pin from the secondary tensioners. Measuring the camshaft end play is the final step, followed by putting the primary timing chain in place.