Crankshaft Main Bearing

MAIN BEARING HOUSING INNER DIAMETER





^ Install main bearing caps without installing main bearings, and tighten main bearing cap bolts to the specified torque. Refer to "ASSEMBLY" for the tightening procedure.
^ Using a bore gauge, measure the inner diameter of the main bearing housing.
Standard 68.944 - 68.968 mm (2.7143 - 2.7153 inch)
^ If out of the standard, replace cylinder block and main bearing caps as an assembly.

NOTE: These components cannot be replaced as a single unit, because they were processed together.

CRUSH HEIGHT OF MAIN BEARING





^ When main bearing cap is removed after being tightened to the specified torque with main bearings installed, the tip end of bearing must protrude. Refer to "ASSEMBLY" for the tightening procedure.
Standard: There must be crush height.
^ If out of the standard, replace main bearings.

MAIN BEARING OIL CLEARANCE
Method by Calculation





^ Install main bearings to cylinder block and main bearing caps, and tighten main bearing cap bolts to the specified torque. Refer to "ASSEMBLY" for the tightening procedure.
^ Measure the inner diameter of main bearing with a bore gauge.
(Bearing clearance) = (Main bearing inner diameter) - (Crankshaft main journal diameter)
Standard
No. 1 and 5 journal 0.001 - 0.011 mm (0.00004 - 0.0004 inch)
No. 2, 3 and 4 journal 0.007 - 0.017 mm (0.0003 - 0.0007 inch)
Limit
No. 1 and 5 journal 0.021 mm (0.0008 inch)
No. 2, 3 and 4 journal 0.027 mm (0.0011 inch)
^ If the calculated value exceeds the limit, select proper main bearing according to main bearing inner diameter and crankshaft main journal diameter to obtain the specified bearing oil clearance. Refer to "HOW TO SELECT MAIN BEARING".

Method of Using Plastigage
^ Remove oil and dust on crankshaft main journal and the surfaces of each bearing completely.
^ Cut plastigage slightly shorter than the bearing width, and place it in crankshaft axial direction, avoiding oil holes.
^ Install main bearings to cylinder block and main bearing caps, and tighten main bearing bolts to the specified torque. Refer to "ASSEMBLY" for the tightening procedure.

CAUTION: Do not rotate crankshaft.





^ Remove main bearing caps and bearings, and using scale on plastigage bag, measure the plastigage width.

NOTE: The procedure when the measured value exceeds the limit is same as that described in the "Method by Calculation".








MAIN BEARING





Undersize





Bearing Oil Clearance