You should first unbolt the primary chain and secondary chain tensioner before removing the camshaft. Engines are assembled with the number one exhaust camshaft bearing bearing marked "1E>." Release the camshaft bearing cap bolts one by one, starting from the back and afterwards take out the bearing caps. It's best to remove the tensioner and camshaft chain from the camshafts, after taking the camshafts, secondary chain and tensioner out together. Look for any damage on the camshafts during the inspection. See if the camshaft bearing journals are bound and be sure there is no oil temporarily obstructing the cylinder head oil holes. Determine if the camshaft sprockets are very worn by looking at them and inspect the cam lobe surfaces for damage. If you find any issues, change the camshaft by measuring actual wear at a standard of 0.0254 mm and not allowing wear past 0.254 mm. Don't forget to take out the
Timing Chain and only set the cylinder heads in their proper place when the
Crankshaft is in the correct location, so as to not harm the valves or pistons. Arrange the camshaft chain on the cams so that the plated links meet the front and line the middle dot on the chain links up with the corresponding dot on the camshaft sprockets. Should the camshaft chain tensioner start hammered in and secured, advance to step two. If something is wrong, compress and clamp the tensioner in a vise, until a pre-made lock pin is able to fit into the holes, at which point you can release it. Open the camshafts and place the compressed and locked chain tensioner between them and the chain. Then, rotate the cams, so their plated links and dots are just above 12:00 o'clock and install them into the cylinder head with the
Rocker Arms positioned correctly. With the bearing caps set in the same position as when taken out, fasten each cap bolt to 12 Nm (105 in. lbs.) in the proper sequence. Later, install the secondary chain tensioner bolts to 12 Nm (105 in. lbs.), take out the locking pin from the secondary tensioners, measure how much the camshafts move at the ends and install the primary timing chain.