Clean the camshaft and gear train parts in solvent. Wipe the cam dry with shop towels only. Compressor can be used to dry the other parts.
Inspect the cam bearing journals for wear, scoring, scuffing, or discoloration from overheating. Replace camshaft if damaged or discolored (Figure 2-128).
Inspect oil pump drive gear on camshaft for damage. Replace camshaft if gear teeth are worn, chipped, or broken.
Measure bearing journal wear. Journals 1, 2, 3, and 4 should be 2.164-2.166 in. (54.975-55.025 mm). Journal 5 should be 2.007-2.009 in. (50.975-51.025 mm).
Mount the camshaft on “V” blocks and measure lift. Lift for both intake and exhaust valve lobes should be 0.281 ± 0.002 in.
(7.133 ± 0.050 mm). Replace camshaft if any lobe is worn below specified range.
Inspect both sprockets for cracks, or chipped, broken teeth. Replace sprockets as a matched set if either one is damaged.
Inspect the timing chain for distortion, stretch, or binding. Replace the chain if damaged.
Inspect the fuel injection pump drive and driven gears for cracks, chipped or broken teeth, and wear. Replace both gears as a set if either one is damaged. Inspect the thrust plate and spacer for wear. Replace either part if damaged or worn.
