Main Bearing

HOW TO SELECT PISTON AND BEARING


Main Bearing


WHEN NEW CYLINDER BLOCK AND CRANKSHAFT ARE USED





1. "Main Bearing Selection Table" rows correspond to main bearing housing grade on rear left side of cylinder block.
- If there is a corrected stamp mark on cylinder block, use it as a correct reference.





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

CAUTION:
There are two main bearing selection tables. One is for odd-numbered journals (No. 1, 3 and 5) and the other is for even-numbered journals (No. 2 and 4). Make certain to use the appropriate table.
This is due to differences in the specified clearances.
4. Apply the symbol obtained to the "Main Bearing Grade Table" to select main bearing.

NOTE:
Service part is available as a set of both upper and lower.

WHEN CYLINDER BLOCK AND CRANKSHAFT ARE REUSED
1. Measure the dimensions of the cylinder block main bearing housing inner diameter and crankshaft main journal diameter individually. Service and Repair.
2. Apply the measured dimension to the "Main Bearing Selection Table".
3. Read the symbol at the cross point of selected row and column in the "Main Bearing Selection Table".

CAUTION:
There are two main bearing selection tables. One is for odd-numbered journals (No. 1, 3 and 5) and the other is for even-numbered journals (No. 2 and 4). Make certain to use the appropriate table.
This is due to differences in the specified clearances.
4. Apply the symbol obtained to the "Main Bearing Grade Table" to select main bearing.

NOTE:
Service part is available as a set of both upper and lower.

MAIN BEARING SELECTION TABLE (No. 1, 3 and 5 journals)






MAIN BEARING SELECTION TABLE (No. 2 and 4 journals)






MAIN BEARING GRADE TABLE (ALL JOURNALS)

Main bearing grade table (All journals) : Refer to Specifications.

USE UNDERSIZE BEARING USAGE GUIDE
- When the specified main bearing oil clearance is not obtained with standard size main bearings, use undersize (US) bearing.
- When using undersize (US) bearing, measure the main bearing inner diameter with bearing installed, and grind main journal so that the main bearing oil clearance satisfies the standard.

CAUTION:





In grinding crankshaft main journal to use undersize bearings, keep fillet R [1.5 - 1.7 mm (0.059 - 0.067 in)].

Bearing undersize table : Refer to Specifications.