Crankshaft Main Bearing

MAIN BEARING HOUSING INNER DIAMETER





^ Install main bearing caps and main bearing beam without installing main bearings, and tighten main bearing cap bolts to the specified torque.
^ Measure the inner diameter of main bearing housing with a bore gauge.
Standard 63.993 - 64.017 mm (2.5194 - 2.5203 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 beam to the specified torque.
^ Measure the inner diameter of main bearing with a bore gauge.
(Oil clearance) = (Main bearing inner diameter) - (Crankshaft main journal diameter)
Standard 0.035 - 0.045 mm (0.0014 - 0.0018 inch) (actual clearance)
Limit 0.065 mm (0.0026 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 engine oil and dust on crankshaft journal and the surfaces of each bearing completely
^ Cut a plastigage slightly shorter than the bearing width, and place it in crankshaft axial direction, avoiding oil holes.
^ Install main bearing to cylinder block and main bearing cap, and tighten main bearing bolts with main bearing beam to the specified torque.

CAUTION: Never rotate crankshaft.





^ Remove main bearing caps and bearings, and using the scale on the 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 CRUSH HEIGHT





^ 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 BOLT OUTER DIAMETER





^ Measure the outer diameters (d1, d2) at two positions as shown in the figure.
^ If reduction appears in A range, regard it as d2
Limit (d1 - d2) 0.11 mm (0.0043 inch)
^ If it exceeds the limit (large difference in dimensions), replace main bearing cap bolt with new one.

Main Bearing Cap





Install main bearing cap bolts in numerical order as shown in the figure as follows:
Inspect the outer diameter of main bearing cap bolt.
Apply new engine oil to threads and seat surfaces of main bearing cap bolts.
Tighten main bearing cap bolts in several different steps.
Torque 35.3 Nm (3.6 kg-m, 26 ft. lbs.)





Turn all main bearing cap bolts 90° clockwise (Angle tightening).

CAUTION: Use the angle wrench [SST: KV10112100 (BT8653-A)] to check tightening angle. Do not make judgment by visual inspection.

After installing main bearing cap bolts, make sure that crankshaft can be rotated smoothly by hand.

MAIN BEARING:

MAIN BEARING

Undersize:

Undersize

Main Bearing Oil Clearance:

Main Bearing Oil Clearance