How to Select Main Bearings

HOW TO SELECT MAIN BEARINGS

When 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. Apply journal diameter grade stamped on crankshaft front side to column in "Main Bearing Selection Table".
3. Find sign (main bearing grade) at crossing of row and column in "Main Bearing Selection Table".

When Cylinder Block and Crankshaft are Reused
1. Measure inner diameter of cylinder block main bearing housing and outer diameter of crankshaft journal.
2. Find measured dimension in "Cylinder block bearing housing inner diameter" row of "Main Bearing Selection Table".
3. Find the measured dimension in "Crankshaft main journal diameter" column in "Main Bearing Selection Table".
4. Select main bearing grade at the point where selected row and column intersect.





Main Bearing Selection Table





Main Bearing Grade Table (All Journals)

Undersize Bearing Usage Guide
^ Use undersize bearing when oil clearance with standard size main bearing is not within specification.





CAUTION: Keep fillet R when grinding crankshaft journal in order to use undersize bearing (all journals).

^ When using undersize bearing, measure the bearing inner diameter with bearing installed, and grind journal until oil clearance falls within specification.





Bearing Undersize Table