The camshafts and Lash Adjusters should always be thoroughly inspected before installation and camshaft endplay should always be checked prior to camshaft removal. Detach the cable from the negative terminal of the battery. Remove the upper and lower intake plenums and the valve covers. Remove the timing chains and the camshaft sprockets. Remove the variable valve timing valve(s) from the top of the number one camshaft journal(s). Mark the camshaft bearing caps from 1 to 4, and with an "I" or an "E", to indicate intake or exhaust. Also mark arrows indicating the front of the engine. Loosen the camshaft bearing caps in two or three steps, in the reverse order of the tightening sequence. Remove the bearing caps and the camshafts. Make a note of the camshaft markings to ensure correct installation. Remove the Lash Adjusters and shims from the cylinder head, keeping the proper shim with each Lash Adjuster. Inspect the camshaft and Lash Adjusters. Lubricate the Lash Adjusters with clean engine oil, then install the Lash Adjusters and shims into their original locations. Apply moly-based engine assembly lubricant to the camshaft lobes and journals. Install the camshafts in their original positions with the dowel pins facing up and inline with the cylinder bank. Apply a bead of RTV sealant to the sealing surfaces of the No. 1 bearing cap(s) and the cylinder head. Install new O-rings on the secondary timing chain tensioner(s) and the VVT oil control orifice on the No. 1 bearing cap(s). Install the bearing caps and bolts and tighten them hand tight. Tighten the bearing cap bolts in several steps, to the specific torque, using the proper tightening sequence. Install the camshaft sprockets and timing chain. Hold the camshafts with a suitable wrench as you tighten the sprocket bolts to the specified torque. The remainder of installation is the reverse of removal. If any part of the valve train was replaced, check and adjust the valve clearance.
