First for the 3.0L engine remove the timing chain rear cylinder bank and pay attention to the orientation of the camshaft caps. Now we can ease and unscrew the camshaft bearing caps gently tapping them if needed , after that align and lift the camshafts. Lokke the positions of the rocker arms before you pull them off and put them in a suitable box for identification. Take the hydraulic lash adjusters out of their respective bores and make certain that they are spaced apart for fitting. Again for the front bank turn the crankshaft to align the camshaft sprockets and torque setting, unscrew the timing chain sprocket and do the same for the camshaft, rocker arm and the lash adjuster. Remove one hydraulic lash adjuster after the other and examine them for signs of wear then use Vernier Calipers and measure their diameters and compare them if there are signs that they gradually taper. Investigate rocker arms and camshaft lobes for wear, camshaft lobe lift and bearing journal with greater attention given to wear. To check oil clearance, the interior of the bearing is cleaned before the camshafts are fitted with Plastigage and the clearance is then read. For endplay, install the camshafts, and measure using a dial indicator. For installation, use oil and fit in the rocker arms and lash adjusters, camshafts and bearing caps and tight them in a certain order. Do tighten the securing bolts of the timing chain sprocket cover after fitting in place, then add oil to the crankcase, but commencing the engine and check for oil leakage. For 3.5L engine, make sure that the engine has been removed, employ the use of camshaft holding tools and inspect the valve clearance before removal. Once these have been taken off and before attempting to install the new ones, you have to be mindful of the position of camshaft caps; and then proceed to loosen them in a pattern that is opposite to the measure of tightness applied in the previous step. Examine tappets and camshafts prior to greasing them and placing the former into their mid-position with the latter centralized with views to tightening some caps just before others. You should therefore fine tune the valve clearances before installing timing chains and the covers. For the 2.7L engine, the engine as well as any related components must be removed before camshaft caps can be loosened and removed strictly according to a certain sequence. Check the rocker arms and lash adjusters; put the viscosity of the lash adjusters, followed by the installation of the Lash adjusters; lastly, align the camshafts in their neutral position. Again include sealant, on the camshaft cap, and fit all caps and tighten them in an orderly manner before fitting VCT units and timing chains. Last of all, turn the crankshaft in order to orient the camshaft lobes upwards, place the rocker arms and proceed to the reverse of the previous steps.