How to Select Main Bearing

When New Cylinder Block and Crankshaft are Used





1. Apply the main bearing housing grade on the bottom face of the cylinder block to the row in "Main Bearings Selection Table".





2. Apply the journal diameter grade on the crankshaft front to the column in "Main Bearings Selection Table".
3. Read the symbol at the cross point of the selected row and column in the "Main Bearings Selection Table".

CAUTION:
- Initial clearance for No. 1, 5 journal and No. 2, 3, 4 journal is different. Use two different selection lists for each part.
- No. 1, 5 journal and No. 2, 3, 4 journal have the same signs but different measures. Do not confuse them.

4. Apply the symbol to the "Main Bearings Grade Table" to select.

NOTE:
- Grade list applies to all journals.
- Service parts are available as a set of both upper and lower.

When Cylinder Block and Crankshaft are Reused
1. Measure the inside diameter of the cylinder block main bearings housing and the outside diameter of the crankshaft journal.
2. Apply measurement in above step 1 to "Main Bearings Selection Table".
3. The following steps are same as in "When New Cylinder Block and Crankshaft are Used". Refer to "HOW TO SELECT MAIN BEARING".














Use Undersize Bearing
- Usage Guide Use undersize (US) bearing when the oil clearance with standard size main bearing is not within specification.
- When using undersize (US) bearing, measure the inside diameter of the bearing installed and grind the journal until the oil clearance falls within specification.








CAUTION:
Do not damage fillet R when grinding crankshaft journal in order to use undersized bearing (All journals).

Fillet R: 1.5 - 1.7 mm (0.059 - 0.067 in)