GMC 12626660 Camshaft Asm

Before pulling the camshaft, the lobe lift should be checked and where a new camshaft is to be fitted, new Lash Adjusters should be used. Start by having the intake manifold, valve covers, rocker arms, pushrods, timing chain, cylinder heads, radiator, air conditioning condenser, and camshaft position sensor repossessed. Put the Lash Adjusters in a container which is of a box shape in order to retain the original position of the equipments and then take off the Lash Adjuster retainers and clean the Lash Adjusters. In case of gum and varnish entrapment, employ suitable gear in removing them without causing blistering to the Lash Adjusters. Take off the camshaft retainer plate and make use of the bolts as you pull the camshaft liter by liter. With the camshaft installed, to measure the camshaft lobe lift set a dial indicator against the pushrod or Lash Adjuster whilst having the cylinder on the compression stroke at TDC. Include the maximum lift and repeat for all valves in the record. Lobe lift can also be done by measuring the camshaft lobe height and base circle using a micrometer after the lobes have been pulled out. Varying degrees of wear, slight pitting, or fracture on the bearing journals, camshaft lobe should be checked for signs of discoloration and uneven wear. Lash Adjusters-clean and inspect for damage and that they rotate freely. Before assembling put oil on camshaft and Lash Adjusters, after that try to fit the camshaft cautiously, set the position of the thrust plate and timing starter. Lastly, change the viscosity of the Lash Adjusters and fit them back in their retainers making sure that they are well aligned then follow the above steps in the reverse manner in which the parts were removed. When the engine is off, before turning it on change the oil and put in a new oil filter.

The steps to remove the camshaft are as follows: 1. Remove the intake manifold. 2. Remove the rocker arms. 3. Remove the pushrods. 4. Remove the timing chain. 5. Remove the camshaft sprocket. 6. Remove the balance shaft drive gear. 7. Remove the fan, radiator, and condenser. 8. Store the lifters in a labeled box. 9. Remove the lifter retainer. 10. Extract the lifters from the bores using a special tool, magnet, or your fingers. 11. Remove the camshaft retainer plate. 12. Use three 6-inch long, 5/16-18 bolts as a handle to remove the camshaft from the block.

The steps to remove the camshaft are as follows: 1. Remove the intake manifold. 2. Remove the rocker arms. 3. Remove the pushrods. 4. Remove the timing chain. 5. Remove the camshaft sprocket. 6. Remove the balance shaft drive gear. 7. Remove the fan, radiator, and condenser. 8. Store the lifters in a labeled box. 9. Remove the lifter retainer. 10. Extract the lifters from the bores using a special tool, magnet, or your fingers. 11. Remove the camshaft retainer plate. 12. Use three 6-inch long, 5/16-18 bolts as a handle to remove the camshaft from the block.

The initial steps to remove the camshaft are disconnecting the cable from the negative battery terminal and relieving the fuel system pressure.

During inspection of the camshaft, you should: 1. Clean the lifter and camshaft with solvent. 2. Check for wear and damage on the lifter and camshaft. 3. Measure the journals and cam lobes for wear. 4. Replace the camshaft and bearings if they are damaged.