How To Select Main Bearing

WARNING: This page is about a different car, the 2012 Nissan Pathfinder. However, it is still accessible from the selected car via links, so may be relevant.

When New Cylinder Block and Crankshaft are Used

"Main Bearing Selection Table" rows correspond to bearing housing grade on rear left side of cylinder block.

Fig 1: Identifying Bearing Housing, Cylinder Bore And Management Grade
Courtesy of NISSAN NORTH AMERICA, INC.
"Main Bearing Selection Table" columns correspond to journal diameter grade on front side of crankshaft.

Fig 2: Identification Code, Pin Journal And Journal Diameter Grade
Courtesy of NISSAN NORTH AMERICA, INC.
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

Measure cylinder block main bearing housing inner diameter and crankshaft main journal diameter. Refer to "INSPECTION AFTER DISASSEMBLY " and "INSPECTION AFTER DISASSEMBLY ".
Correspond the measured dimension in "Cylinder block main bearing housing inner diameter" row of "Main Bearing Selection Table".
Correspond the measured dimension in "Crankshaft main journal diameter" column of "Main Bearing Selection Table".

Select main bearing grade at the point where selected row and column meet in following selection table.

Fig 3: Main Bearing Selection Chart

Courtesy of NISSAN NORTH AMERICA, INC.

MAIN BEARING GRADE CHART (ALL JOURNALS)

Grade number		Thickness Unit: mm (in)	Width Unit: mm (in)	Identification color	Remarks
0		2.500 - 2.503 (0.0984 - 0.0985)	19.9 - 20.1 (0.783 - 0.791)	Black	Grade is the same for upper and lower bearings.
1		2.503 - 2.506 (0.0985 - 0.0987)		Brown
2		2.506 - 2.509 (0.0987 - 0.0988)		Green
3		2.509 - 2.512 (0.0988 - 0.0989)		Yellow
4		2.512 - 2.515 (0.0989 - 0.0990)		Blue
5		2.515 - 2.518 (0.0990 - 0.0991)		Pink
6		2.518 - 2.521 (0.0991 - 0.0993)		Purple
7		2.521 - 2.524 (0.0993 - 0.0994)		White
01	UPR	2.503 - 2.506 (0.0985 - 0.0987)		Brown	Grade is different for upper and lower bearings.
01	LWR	2.500 - 2.503 (0.0984 - 0.0985)		Black
12	UPR	2.506 - 2.509 (0.0987 - 0.0988)		Green
12	LWR	2.503 - 2.506 (0.0985 - 0.0987)		Brown
23	UPR	2.509 - 2.512 (0.0988 - 0.0989)		Yellow
23	LWR	2.506 - 2.509 (0.0987 - 0.0988)		Green
34	UPR	2.512 - 2.515 (0.0989 - 0.0990)		Blue
34	LWR	2.509 - 2.512 (0.0988 - 0.0989)		Yellow
45	UPR	2.515 - 2.518 (0.0990 - 0.0991)		Pink
45	LWR	2.512 - 2.515 (0.0989 - 0.0990)		Blue
56	UPR	2.518 - 2.521 (0.0991 - 0.0993)		Purple
56	LWR	2.515 - 2.518 (0.0990 - 0.0991)		Pink
67	UPR	2.521 - 2.524 (0.0993 - 0.0994)		White
67	LWR	2.518 - 2.521 (0.0991 - 0.0993)		Purple

Undersize Bearing Usage Guide

When the specified main bearing oil clearance is not obtained with standard size main bearings, use underside (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 the fillet R [1.5 - 1.7 mm (0.059 - 0.067 in)].

Fig 4: Identifying Crankshaft Journals And Crankshaft Pins

Courtesy of NISSAN NORTH AMERICA, INC.

BEARING UNDERSIZE CHART

Unit: mm (in)
Size	Thickness
US 0.25 (0.0098)	2.633 - 2.641 (0.1037 - 0.1040)