Crankshaft Main Bearing: Testing and Inspection
MAIN BEARING CLEARANCE1. Remove main bearing caps.
2. Clean main bearings and main journals.
3. Place a piece of plastic-type gaging material across the full width of main bearing (parallel to crankshaft) on the journal while avoiding the oil hole.
4. Install main bearing caps and bearing cap supports to cylinder block. Install each cap in ascending order of numbers 1, 2, 3, 4 and 5 starting from the crankshaft pulley end and going to the flywheel end. Make sure all arrow marks point toward crankshaft pulley end.
^ Tighten main bearing cap bolts to 54 Nm (40 ft. lbs.).
CAUTION: Do not rotate crankshaft while plastic-type gaging material is installed.
NOTE: Main bearing caps MUST be torqued to specification in order to obtain accurate measurement.
5. Remove main bearing cap and, using scale on plastic-type gaging material envelope, measure plastic-type gaging material width at its widest point. If clearance exceeds specification, replace main bearing. Standard main bearing clearance is 0.02 to 0.04 mm (0.0008 to 0.0016 inch). If clearance exceeds 0.06 mm (0.0023 inch), replace main bearing. Always replace both upper and lower bearing halves as a set.
NOTE: A new standard main bearing may produce proper clearance. If not, it will be necessary to regrind crankshaft journal and use a 0.25 mm (0.0098 inch) undersize bearing. After selecting new main bearing, recheck clearance as described above. Service and Repair