Crankshaft Main Bearing

MAIN BEARING HOUSING INNER DIAMETER





^ Install main bearing caps and main bearing without installing main bearings, and tighten main bearing cap bolts to the specified torque.
^ Measure the inner diameter of main bearing housing with bore gauge.
Standard 68.944 - 68.968 mm (2.7143 - 2.7153 inch)
^ If out of the standard, replace cylinder block and main bearing caps as assembly.

NOTE: Cylinder block cannot be replaced as a single part, because it is machined together with main bearing caps.

MAIN BEARING OIL CLEARANCE
Method by Calculation





^ Install main bearings to cylinder block and main bearing caps, and tighten main bearing cap bolts with main bearing to the specified torque.
^ Measure the inner diameter of main bearing with 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.

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 with main bearing to the specified torque.

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.

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.
Standard: There must be crush height.
^ If the standard is not met, replace main bearings.

Main Bearing Cap





Install each main bearing cap bolt as follows:
Apply new engine oil to threads and seating surface of main bearing cap bolts, and tighten all bolts temporarily.
Tighten main bearing cap bolt (M12) in order of 1 to 10.
Torque 39.2 Nm (4.0 kg-m, 29 ft. lbs.)
Tighten main bearing cap sub bolt (M9) in order of 11 to 20.
Torque 29.4 Nm (3.0 kg-m, 22 ft. lbs.)





Tighten main bearing cap bolt (M12) to 40° clockwise in order of 1 to 10. (Angle tightening)

CAUTION: Use angle wrench (SST) to check tightening angle in step d and e. Do not make judgment by visual inspection.

Tighten main bearing cap sub bolt (M9) to 30° clockwise in order of 11 to 20. (Angle tightening)
Tighten side bolt (M10) in order of 21 to 30.
Torque 49 Nm (5.0 kg-m, 36 ft. lbs.)
After installing main bearing cap bolts, make sure that crankshaft can be rotated smoothly

MAIN BEARING:

MAIN BEARING

Undersize:

Undersize

Main Bearing Oil Clearance:

Main Bearing Oil Clearance