To verify camshaft lobe lift, and check for wear, begin by removing the rocker arm cover. Place the number one piston at the top dead center on the compression stroke. Screw a dial indicator on the engine so that the plunger of the indicator rests on the top surface of the first rocker directly below the push rod. Rotate the crankshaft in protractor clockwise so that you can bring dials indicator to zero and then continue until it reads in the opposite direction the maximum cam lobe lift. Measure this and then put the piston back to TDC and do the check on the next valve, taking a piston to TDC in the firing order, rotating the crank 180 for the next cylinder. carrying out the checks, it is possible to compare it with the specified norms; if lobe lift is lower than the established number, then, it is required to install a new camshaft. For removal preheat and remove the alt/front/brake spark plugs, intake manifold, carb, air cleaner, water pump, freon, heater valves, trans cooler bracket, throttle lever linkage, alt & generator front plate & brackets, lower valve cover, engine fan, alternator & brackets, dipstick tube, exhaust manifold, power steering pump & hoses, radiator, plumbing & all brackets, Intake manifold heater crossover, and drivebelts Disconnect the push rods and lifters, and take off the timing gear cover, distributor, and oil pump drive shaft, and the head light bezels, grille, and bumper filler panel. Remove the access panel and unbolt the air conditioning condenser baffles without having to disconnect the refrigerant lines. Place the camshaft so that the holes in the camshaft gear correspond to the drilled holes in the thrust plate, unscrew the bolts and slowly pull out the camshaft and gear out of the block supporting it not to damage the bearings. The crankshaft gear should come off with ease on the crankshaft. After camshaft cleaning, it is required to check the bearing journals to see if they have worn out; if they are worn out, both the camshaft and bearings will require replacement. Check the dimension and roundness of the bearing journals using micro meters and compare the clearance with required specifications. Check the camshaft lobes; if these have changed color or are worn then new lobes may be installed; otherwise the camshaft may be reused. Inspect the camshaft drive and the driven gears and if the camshaft is worn replace both the camshaft drive is well as the driven gears. It is possible to measure gear end clearance and estimate the need in the spacer ring or thrust plate replacement. Camshaft bearing replacement also needs professional tools and therefore transport the block to a machine shop. For installation, lubricate the camshaft journals and the tops of the camshaft lobs, next slide the camshaft into the engine and then install the gear onto the crankshaft sprocket, care must be taken to align the timing marks. Realignment of access holes and usage of Locktite on the threads before the application of thrust plate bolts to the require torque channel in the reverse sequence of the removal process.
