Connecting Rod Bearing Service

Remove rod caps and mark for proper installation. Replace defective bearings. Use Plastigage method for bearing clearance check.
NOTE: If any undersized crankshafts are used, all journals will be .010" and an "X" will be stamped on the No. 6 counterweight.
Measure outside diameter of rod bearing journals to determine if out-of-round or tapered. Standard rod journal out-of-round is .00025" (.006 mm). Standard rod journal taper is .0015" (.038 mm). Standard rod journal runout is .0005" (.013 mm).
When checking rod clearances, crankshaft does not have to be supported. Instead, turn crankshaft until rod to be checked starts moving toward top of engine, thus unloading lower bearing.
Place Plastigage in bearing cap, parallel with crankshaft (not over oil hole or groove). Install rod bearings and tighten cap. Always install caps with markings in original positions.
DO NOT turn crankshaft with Plastigage installed. Remove rod bearing cap from crankshaft and measure Plastigage at widest part (using scale on Plastigage package). If clearance exceeds specifications, replace bearing.
Selective fitting is required on each connecting rod. Bearings are available in standard, .0010" or .0020" undersize for new and used standard size crankshaft. Bearings of .010" or .020" undersize are for use with reconditioned crankshafts. After inspection and/or replacement, coat bearings with oil. Tighten rod caps in two steps.
NOTE: Connecting rod bearing cap and rod identification numbers must remain on same side. Always replace bearings in pairs. Never use new bearing with used bearing. Never file or grind rods or caps when fitting bearings.
Check rod side clearance. Standard rod side clearance is .006-.020" (.15-.50 mm). If clearance is less than specification, remove rod and cap. Check for scratches, burrs, or dirt between crankshaft and rod. Dress minor imperfections with oil stone.
During assembly, ensure oil hole in bearing aligns with oil hole in connecting rod. Check bearing tangs are seated in appropriate slots in rod and cap. Ensure connecting rod bolt heads are properly seated in rod.