Cadillac 12565308 Camshaft Asm

Disconnect the cable from the negative battery terminal, then rotate the engine until the #1 cylinder is at Top Dead Center (TDC) on the compression stroke. Remove the valve cover(s) and the timing belt. Rotate the crankshaft 60 degrees counterclockwise to prevent the valves from possibly hitting the pistons, then remove the camshaft sprocket bolts and sprockets. Each camshaft bearing cap has a double-digit identifying number etched on it, with specific numbering for the exhaust and intake camshaft bearing caps on both sides of the engine. Loosen the camshaft bearing cap bolts progressively by half a turn at a time to gradually release the pressure of the valve springs. Withdraw the caps, noting their markings and the presence of locating dowels, then remove the camshafts and front oil seals, identifying the intake and exhaust camshafts by their respective stamps. Use twelve small, clean containers to store each Lash Adjuster, ensuring they are not interchanged. With the camshafts and Lash Adjusters removed, check for signs of wear and measure the outside diameter of each Lash Adjuster at multiple points. Visually examine the camshaft lobes and bearing journals for wear or pitting, and measure the diameter of each journal. To check the bearing journal running clearance, clean all bearing surfaces, install the camshafts and bearing caps with Plastigage across each journal, then measure the width of the compressed strands. If any bearing is worn beyond specified limits, install a new camshaft and repeat the check. For camshaft endplay, clean the bearing surfaces, install the camshafts and bearing caps, then measure the endplay using a dial indicator. If the endplay exceeds specified limits, install a new camshaft. Confirm the crankshaft is positioned at 60 degrees BTDC, then oil the cylinder head Lash Adjuster bores and install the Lash Adjusters in their original positions. Oil the camshaft bearing surfaces and install the camshafts in their original locations, ensuring the pins are positioned correctly. Apply silicone sealer to the forward edge of the front bearing caps and check that all mating surfaces are clean. Oil the camshaft journals and lobes, then install each camshaft bearing cap, ensuring the numbered side faces outwards. Tighten the camshaft bearing cap bolts in sequence until each cap touches the cylinder head, then to the specified torque. Coat the lip of the camshaft seal with clean engine oil, press it into the end of the bearing cap, and use a seal driver to ensure it is flush and square. Finally, install the camshaft sprockets to the correct camshafts, ensuring the camshaft pin is in the same numbered slot on the sprocket it was removed from, and tighten the new camshaft sprocket bolt to the specified torque.

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.

The retainer and lifters should be installed as an assembly, with original lifters returned to their original locations if reused. The lifter retainer bolts should be tightened.