The tools in this procedure are unique, therefore, it is suggested that one reads the whole procedure before procuring the necessary tools. Camshafts should always have a thorough check before installation while the camshaft end play should preferably be checked before the removal of the same. First, turn off connection of the cable to the negative terminal of the battery and then remove the valve covers. Turn the engine clockwise until you're not able to view anymore the crankshaft pulley after which align the V6 or V8 on camshaft sprockets. With a permanent marker draw alignment marks to the secondary timing chain links on the side of the V6 or V8 marks on both camshaft sprockets. Lift the camshaft sprockets using the spanner wrench and then unscrew the sprocket bolts then tight the bolts to a proper tightness. If the sprockets turn during this procedure, position them at the 12 o'clock position. Place the timing chain tensioner wedge through the hole designed in the upper part of the cylinder head to hold the secondary chain and tensioner in place when you have pulled out the camshaft. If both camshafts are being removed then, there will be a need to use two of the wedges. Failing to apply a timing chain wedge may cause over extension of the secondary tensioner through the timing chain cover, whereby the cover has to be removed to reset it. The Camshaft Position Sensor should be disconnected, the camshaft sprocket bolts should be removed and the sprockets from the camshaft hub. Some engines use markings on the camshaft bearing caps for proper reassembly; if this is the case, it's critical to remember them when you're preparing to tighten the camshaft bearing cap bolts to also begin with the most distant bolts and after that proceed towards the middle. They will need to retire back to the specific area they were found; therefore, keep the caps organized. Remove the bearing caps and orient the rocker arms with the cap screw hole uppermost ,for ease of reassembly. Take out the camshaft(s) from the cylinder head and call them left or right for easy identification. The wear the lifters have on the camshaft sprockets, the cracks or any sign of wear on the chains, and even the damage evident on the surface of the bearing system on the camshaft should also be inspected. The oil clearance for each camshaft bearing journal is the difference between the outside diameter of the journal and the specified journal diameter. Inspect and measure camshaft runout and endplay and check if they fall within the standard range stating the specifications of the two. The amount of camshaft lobe lift can be measured with a micrometer: intake lobes must be compared to each other and exhaust lobes compared to each other; if figures are more than 0,005 inch-the change of the camshaft is needed. For installation, use moly based engine assembly lube on the camshaft lobes and journals before fixing the camshaft(s) to the cylinder head with the dowel pins locating at 10 o/clock.. Set the bearing caps and their bolts and make them turn as tightly as possible by hand, then ratchet them more than the middle bolts. Slip the camshaft sprocket teeth onto the drive chain links with the V6 or V8 to be oriented in the proper direction. Remove the Camshaft sprocket bolts and after cleaning them well, grease the washers and bolt and then torque to the prescribed values. Take out the timing chain wedge(s), put the camshaft position sensor, place the valve covers, and join the cable to the negative terminal of the battery.
