Incase of removal and installation of the rocker arms and shaft one is required to first drop the rocker arm. Fourth, disconnect the rocker arm shaft by unscrewing four bolts and retainers of the engine part. Raise both the rocker arm shaft and the two rocker arms as one piece. If some of the rocker arms are to be replaced, simply slide off any rocker arms that may be on the shaft. During reassembly, make sure that the rocker arms are assembled into the left and right sets since the intake and exhaust side rocker arms are different, thanks to the 4-bolt shaft and, therefore, must be assembled in a particular sequence. The rocker arm and shaft assembly is now fitted with the aid of the notch that is provided at the end of the shaft in line with the center line of the engine with the left head front and the right head back. The rocker arm shaft retainers are of different lengths, ensure that the long ones are fitted in the second and fourth position. Progressively increase the torque applied on the rocker arm shaft bolts beginning with the centre bolt to the appropriate torque figure; the lifter needs 20 minutes bleed time after installation before the engine is started. Finally add back the rocker arm cover(s) if you pulled it/them off.