Chevrolet 12638426 Camshaft Asm

When the camshaft is being replaced it is advisable to replace the Lash Adjusters as well, because new Lash Adjusters are not supposed to be used when the camshaft is also new. The removal of the camshaft and Lash Adjuster is well illustrated by the following step by step process recommended by the factory. First, it is possible to remove the engine, but it is not obligatory; however, it will make the process easier. Second, it is the intake manifold or supercharger, the valve covers, rocker arms, pushrods, timing chain, timing chain tensioner, cylinder heads, oil pan, oil pump, and oil deflector. Lash Adjusters also should be stored in a box marked clearly before they are removed so that they can be returned to the storage locations they occupied after delivery. The Lash Adjuster retainers and Lash Adjusters can then be removed as an assembly and as much as possible bearing markings for reuse are identified. After that, the camshaft retainer plate bolts should be removed, paying attention to the positions of the plate. Long bolts or a single bolt can be turned into the camshaft sprocket bolt hole to help in extraction of the camshaft. The camshaft should be gently slid out, where it must be supported close to the block in a bid to avoid marring the bearings. Before installing the camshaft, the bearing journals as well as the lobes area should be coated with assembly lube; this ensures that the camshaft is slid into the engine while propping it to reduce of bearing damage. The camshaft should be rotated in order to align the dowel pin and then the retainer plate should be fitted and fixed in place. Timing chain and sprockets should then be fitted in its proper place. Lash Adjusters must be oiled with clean engine oil and then placed in the retainers as require while making certain that they are well aligned. Retainers and Lash Adjusters should be mounted modulo, namely, if some Lash Adjusters were returned they must be placed on the same bank. Finally, the Lash Adjuster retainer bolts should be tightened and the rest of the procedure is but the reversal of the list above. Last but not the least, before starting of the car's engine one should change the oil and also to replace the oil filter.

If the lifters are stuck due to gum and varnish buildup, they can be extracted using a special tool or, in some cases, a small magnet or fingers.

Tighten the bearing cap bolts in the specified order, then repeat the process for the left-side cylinder head camshafts.