To avoide sucking in of air into the lash adjusters do not rotate the rocker arm assemblies upside down. In case they are placed on a bench, they should not rest on the lash adjusters in order to avoid the breakage of the plastic retainers and the lash adjusters. Begin by removing the valve cover(s) and marking the rocker arms and pedestals for identification, noting there are four per cylinder: There are two intakes and two exhausts. Remove each rocker arm shaft bolt about a quarter turn in the opposite direction that it was tightened when removing the rocker shaft and the rockers in one assembly. Check each rocker arm for signs of wear, cracks and damage, rotate the rollers, check that the surfaces of the lash adjuster are in good shape. The lash adjuster must not be pulled out of the rocker arms so that it does not get damaged. Look at the state of pivot area and the shaft and if it is seen that some parts are too worn out, then they should be replaced. Check the orientation of the axle for the roller tip and inspect the hydraulic lash adjuster-to-valve stem tip contact surface for signs of wear. For the removal of rocker arms and pedestals for inspection, the dowel pins can be removed by using a 4 mm screw, nut, washer and spacer; when reinstalling it is important to apply new dowel pins. Should rocker arms or pedestals have been removed for maintenance then the shafts should be lubricated and the rocker arms place in their proper direction; the intake rockers on the intake shaft and the exhausts on the exhaust shaft. Be certain that the notches facing up when assembling so as not to harm the rocker arm shafts. Install new dowel pins in the condition that they should penetrate deepest into each pedestal. Place the rocker arm assemblies with the valvetrain in a no-load condition with the camshaft and crankshaft sprockets aligned at TDC number 1; tighten the right side rocker arm assembly bolts in the proper sequence; install and tight the left rocker arm assembly bolts. Make sure top of the notches on the left rocker arm shafts is directed forward and upward while that of the right rocker arm shafts is also directed backward and upward. Last of all, reinstall every component in a backward order to which you removed; switch on the engine and examine for leakage of oil.