This procedure is for the 3.3/3.8 liter engine only and the engine must be taken out of the car and placed in an engine stand for the second half of the work. To confirm camshaft lobe lift with the cylinder head installed remove the valve cover(s), and with the number one
Piston at TDC on the compression stroke, Place the wide end of a dial indicator over the engine above the plunger and use the thin end to push the plunger up until it fits over the pushrod then zero the indicator, turn the crank slowly clockwise till the needle stops and goes down, this note the maximum cam lobe lift. Do this for the other rocker arms and remaining valves but make certain that each piston is at TDC on the compression stroke. If the lobe lift is lower than the specifications laid down then it is apparent that cam lobe wear has happened, in which case a replacement of the camshaft becomes necessary. Remove the cylinder head and then with the help of the micrometer measure the lobe height and base circle and then find the lobe lift by subtracting the value of base circle from the value of lobe height. For removal, take off the timing chain, sprockets, lifters as well as the push rods Next, take off the camshaft thrust plate, and the you use a long bolt to act as a handle to pull out the camshaft gently while supporting the bearings not to be damaged. Check the journals for wear, pitting or seizure etc. wash the same and by using micrometer find out whether the size has been increased due to excessive wear or out of round condition. Check the camshaft lobes for any signs of colour change, roughness, or dimensional change; if the lobes are in healthy condition and lobe lift measurements are within the limit, the camshaft can be reused. Lay obverses of bearings with block and using a small hole gauge and micrometer check inside diameter and calculate the oil clearance this must indicate that it is a new bearing. Again camshaft bearing replacement involves some specific tools and hence the block should be taken to auto machine shop for handling.