If the camshaft is being replaced, always install new Lash Adjusters as well, as old Lash Adjusters should not be used on a new camshaft. The manufacturer states that the engine should be removed for this procedure. Begin by having the air conditioning system discharged by a technician, then relieve the fuel system pressure and disconnect the negative battery terminal. Remove the radiator, air conditioning condenser, and auxiliary automatic transmission fluid cooler if equipped. Disconnect the power steering cooler and move it aside if equipped, then remove the valve covers, intake manifold, rocker arms, pushrods, timing chain, camshaft position actuator, and cylinder heads. Before removing the Lash Adjusters, store them in a clearly labeled box to ensure they are reinstalled in their original locations. Remove the Lash Adjuster retainers and Lash Adjusters, ensuring they are stored cleanly, and do not attempt to withdraw the camshaft with the Lash Adjusters in place. If the Lash Adjusters are stuck due to gum and varnish, special tools may be required for extraction, although newer engines may allow for easier removal. Avoid using pliers on Lash Adjusters unless they are to be replaced, as this can damage them. Remove the bolts and camshaft retainer plate, noting the orientation, then thread a bolt into the camshaft sprocket bolt hole for easier removal. Carefully pull the camshaft out while supporting it near the block to prevent damage to the bearings. Measure the camshaft lobe height and base circle to determine lobe lift, recording the figures for future reference. After cleaning the camshaft, inspect the bearing journals for wear and damage, and measure them with a micrometer. Check the camshaft lobes for discoloration and wear; if they are in good condition, the camshaft can be reused. Clean the Lash Adjusters thoroughly and check for wear, ensuring that used roller Lash Adjusters cannot be reinstalled with a new camshaft. Always use new Lash Adjusters with a new camshaft. Lubricate the camshaft bearing journals and lobes with assembly lube before sliding the camshaft into the engine, taking care not to damage the bearings. Apply thread-locking compound to the camshaft retainer bolts and allow it to cure before installation. Position the camshaft correctly, install the thrust plate, and tighten the bolts to the specified torque. Install the timing chain and sprockets, as well as the camshaft position sensor with a new O-ring. Lubricate the Lash Adjusters with clean engine oil and install them in the retainers, ensuring proper alignment. Finally, complete the installation in reverse order, and before starting the engine, refill the cooling system, change the oil, and install a new oil filter.
Posted by GMPartsGiant Specialist 
