Camshaft should alway be checked very well before it is fitted and the end play should be checked before removing the camshaft. On any repair job of the camshaft it is advisable to replace the 
Rocker Arms and hydraulic lifters; used parts must not be placed back into use. The camshaft bearing caps are numbered and lettered with a raised arrow pointing in the direction of the front of the engine. Before the camshaft can be removed, it will be necessary to unbolt and set aside such things as the plenum, intake manifold, valve covers, CMP sensors, camshaft actuators, 
Timing Cover, 
Timing Chains, and camshaft sprockets. It is recommended that the camshaft endplay should be checked using a dial indicator and a prybar but carefully to avoid damaging the lobes. Probably the most professional way to store bearing caps and lifters is to put them in a box, which has labels for each part on it. To do the bearing cap bolts and caps off, then the camshaft has to be lifted from the cylinder head. After washing and inspecting the camshaft degrees for its wearing or damage then it has to be taken to the machine shop. During installation always make sure that there are sealing rings and apply a layer of assembly lube on the bearing journals and the cam lobes. Engineer the camshafts to be in the correct position on the bearing journals, apply lubrication to the interior region of the bearing caps and afterwards fit them properly while aligning them. Torque the bearing cap bolts progressively in a sequence and re-torque them in accordance with the recommended torque. Perform same procedure for left side cylinder head camshaft and finally fix in the reverse order that it was removed. Last but not least, drain out the old oil and replace it with a fresh one together with a new oil filter, start up the engine and look for any sign of leakage.