Service Limits & General Specifications
HOW TO SELECT MAIN BEARINGWhen New Cylinder Block and Crankshaft are Used
1. "Main Bearing Selection Table" rows correspond to bearing housing grade on rear left side of cylinder block.
2. "Main Bearing Selection Table" columns correspond to journal diameter grade on front side of crankshaft.
3. Select main bearing grade at the point where selected row and column meet in "Main Bearing Selection Table".
When Cylinder Block and Crankshaft are Reused
1. Measure cylinder block main bearing housing inner diameter and crankshaft main journal diameter. Refer to Specifications.
2. Correspond the measured dimension in "Cylinder block main bearing housing inner diameter" row of "Main Bearing Selection Table".
3. Correspond the measured dimension in "Crankshaft main journal diameter" column of "Main Bearing Selection Table".
4. Select main bearing grade at the point where selected row and column meet in following selection table.
Main Bearing Selection Table:
Main Bearing Grade Table (All Journals):
MAIN BEARING HOUSING INNER DIAMETER
^ Install lower cylinder block without installing main bearings, and tighten lower cylinder block bolts to the specified torque. Refer to EM-112, "ASSEMBLY" for the tightening procedure. Disassembly and Assembly
^ Measure the inner diameter of main bearing housing with bore gauge.
Standard: 74.993 - 75.017 mm (2.9525 - 2.9534 in)
^ If out of the standard, replace cylinder block and lower cylinder block as assembly.
NOTE: Cylinder block cannot be replaced as a single part, because it is machined together with lower cylinder block.
MAIN BEARING OIL CLEARANCE
Method by Calculation
^ Install main bearings to cylinder block and lower cylinder block, and tighten lower cylinder block bolts to the specified torque. Refer to EM-112, "ASSEMBLY" for the tightening procedure. Disassembly and Assembly
^ Measure the inner diameter of main bearing with bore gauge.
(Bearing clearance) = (Main bearing inner diameter) - (Crankshaft main journal diameter)
Standard: 0.035 - 0.045 mm (0.0014 - 0.0018 in) (actual clearance)
Limit: 0.065 mm (0.0026 in)
^ If the calculated value exceeds the limit, select proper main bearing according to main bearing inner diameter and crankshaft main journal diameter to obtain specified bearing oil clearance. Refer to EM-120, "HOW TO SELECT MAIN BEARING". How to Select Connecting Rod Bearing
Method of Using Plastigage
^ Remove engine 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 lower cylinder block, and tighten lower cylinder block bolts to the specified torque. Refer to EM-112, "ASSEMBLY" for the tightening procedure. Disassembly and Assembly
CAUTION: Do not rotate crankshaft.
^ Remove lower cylinder block 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 lower cylinder block is removed after being tightened to the specified torque with main bearings installed, the tip end of bearing must protrude. Refer to EM-112, "ASSEMBLY" for the tightening procedure. Disassembly and Assembly
Standard: There must be crush height.
^ If the standard is not met, replace main bearings.
MAIN BEARING
Undersize
Main Bearing Oil Clearance:
Main Bearing Oil Clearance