Main & Connecting Rod Bearing Service
- Remove engine from vehicle and remove piston and rod assemblies as previously outlined. Remove crankshaft pulley and engine front cover. Remove timing chain tensioner and vibration damper. Remove oil pump driven gear. See OIL PUMP REMOVAL .
- Remove oil baffle plate and Woodruff key from crankshaft end. Remove bolts from camshaft thrust plate. Pull camshaft, timing sprocket and crankshaft sprocket out far enough to remove from crankshaft. Remove clutch and flywheel.
- Bend up lock tabs on main bearing caps and remove nuts. Remove main bearing cap with bearing. Remove crankshaft and thoroughly clean.
- Measure diameter of main bearing and connecting rod bearing journals. If journals, are over 0.002" from standard size, crankshaft must be ground. Crankshaft can be ground 0.010", 0.020" & 0.030" undersize. Check crankshaft runout, runout must not exceed 0.001".
- Main and connecting rod bearing clearance is checked with the Plastigage method. Place a small piece of Plastigage wire on crankshaft bearing surface. With bearings thoroughly clean, install main bearing cap or rod bearing cap and tighten to specification. Do not turn crankshaft. Remove main or rod cap and check flattened wire against scale on back of Plastigage package to determine clearance.
- Main bearing bores in crankcase, main bearings and crankshaft are color coded. The correct combination of colored components will obtain correct clearance of main bearings. See chart to determine correct combination of colored components.MAIN BEARING CLEARANCE COLOR CODE
Main Bearing Bore Crankshaft Main Bearing Green Green Brown Brown Green Blue Yellow Brown Green Black Brown Brown Blue Green Blue Green Blue Brown Black Blue Brown - Install bearing halves in crankcase and caps. Coat bearings with oil and install crankshaft. Install thrust washers. See THRUST BEARING ALIGNMENT . Install crankshaft oil seal. See REAR MAIN BEARING OIL SEAL SERVICE .
- Install oil seals in sides of rear main cap. Main bearing caps are numbers 1 through 4 and must be installed that order from front to rear. Install main bearing caps and tighten nuts to specifications. Bend lock tabs to secure main bearing cap nuts. Make sure crankshaft turns freely.
- Install remaining components in reverse of removal order or as previously outlined. Install timing chain correctly. See VALVE TIMING . Install engine as previously outlined.