Main Bearing General Information

WARNING: This page is about a different car, the 2008 Suzuki Grand Vitara, 2007 Suzuki Grand Vitara, and 2006 Suzuki Grand Vitara. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Before inspecting main bearings, note the following points.

Service main bearings are available in standard size and 0.25 mm (0.0098 in.) undersize, and each of them has 5 kinds of bearings differing in tolerance.
Upper half of bearing (1) has oil groove (2) as shown in figure. Install this half with oil groove toward cylinder block.

Fig 1: Identifying Bearing & Oil Groove
Courtesy of SUZUKI OF AMERICA CORP.
Lower half of bearing does not have oil groove.

Visual Inspection

Check bearings for pitting, scratches, wear or damage.

If any malcondition is found, replace both upper and lower halves. Never replace either half without replacing the other half.

Main Bearing Clearance

NOTE: Do not rotate crankshaft while gauging plastic is installed.

Check clearance by using gauging plastic (1) according to the following procedure.

Remove lower crankcase.
Clean bearings and main journals.
Place a piece of gauging plastic (1) to full width of bearing (parallel to crankshaft) on journal, avoiding oil hole.

Fig 2: Identifying Plastic Gauging Piece
Courtesy of SUZUKI OF AMERICA CORP.
Install lower crankcase to cylinder block without applying sealant referring to MAIN BEARINGS, CRANKSHAFT AND CYLINDER BLOCK REMOVAL AND INSTALLATION .
Remove lower crankcase, and using scale (2) on gauging plastic (1) envelop, measure gauging plastic (1) width at its widest point. If clearance exceeds its limit, replace bearing. Always replace both upper and lower inserts as a unit.
A new standard bearing may produce proper clearance. If not, it will be necessary to regrind crankshaft journal for use of 0.25 mm undersize bearing.

After selecting new bearing, recheck clearance.

Main bearing clearance for standard size bearing

Standard: 0.0210-0.0390 mm (0.0009-0.0015 in.)

Limit: 0.0520 mm (0.0020 in.)

Main bearing clearance for undersize bearing

Standard: 0.0240-0.0420 mm (0.0010-0.0016 in.)

Limit: 0.0550 mm (0.0021 in.)

Fig 3: Removing Lower Crankcase & Using Scale
Courtesy of SUZUKI OF AMERICA CORP.

Selection of Main Bearings

Standard bearing

NOTE: The meaning of "Upper" and "Lower" described in this procedure are the following.

Upper: It is meaning of main bearing installed in cylinder block side journal.
Lower: It is meaning of main bearing installed in lower crankcase side journal.

If engine is under one of the following conditions, select a new standard bearing as follow, and install it.

Bearing is in malcondition.
Bearing clearance is out of specification.
Crankshaft or cylinder block is replaced.

First check journal diameter. As shown in figure, crank web has stamped numbers and alphabet at the center. Six kinds of numbers ("4" through "9") represent the following journal diameters.

Journal diameter

JOURNAL DIAMETER SPECIFICATION

Stamped numbers	Journal diameter
4	65.0030-65.0060 mm (2.55917-2.55928 in.)
5	65.0000-65.0029 mm (2.55905-2.55916 in.)
6	64.9970-64.9999 mm (2.55893-2.55904 in.)
7	64.9940-64.9969 mm (2.55882-2.55892 in.)
8	64.9910-64.9939 mm (2.55870-2.55881 in.)
9	64.9880-64.9909 mm (2.55858-2.55869 in.)

Fig 4: Identifying Crank Web

Courtesy of SUZUKI OF AMERICA CORP.

Next, check journal bore diameter.

On lower crankcase, 4 alphabets (1) are stamped as shown in figure.

Three kinds of alphabets (A, B and C) represent the following journal bore diameters.

Journal bore diameter

JOURNAL BORE DIAMETER SPECIFICATION

Stamped alphabet	Bearing cap bore diameter (without bearing)
A	70.0000-70.0060 mm (2.75590-2.75613 in.)
B	70.0061-70.0120 mm (2.75614-2.75637 in.)
C	70.0121-70.0180 mm (2.75638-2.75660 in.)

Fig 5: Identifying Stamped Alphabet On Lower Crankcase

Courtesy of SUZUKI OF AMERICA CORP.

There are 5 kinds of standard bearings differing in thickness. To distinguish them, they are painted in the following colors at the position as indicated in figure.

Each color indicates the following thickness at the center of bearing.

NOTE: The following bearing are not supplied because they are unnecessary in this selection procedure.

Upper main bearing: Brown
Lower main bearing: Black

Standard size main bearing thickness

MAIN BEARING THICKNESS SPECIFICATION

Color painted	Bearing thickness
Black	2.4970-2.5000 mm (0.09831-0.09842 in.)
Colorless (no paint)	2.5000-2.5030 mm (0.09843-0.09854 in.)
Yellow	2.5030-2.5060 mm (0.09855-0.09866 in.)
Blue	2.5060-2.5090 mm (0.09867-0.09877 in.)
Pink	2.5090-2.5120 mm (0.09878-0.09889 in.)
Brown	2.5120-2.5150 mm (0.09890-0.09901 in.)

Fig 6: Identifying Paint Mark For Bearing Size Identification

Courtesy of SUZUKI OF AMERICA CORP.

From number stamped on crank webs at its center and alphabets stamped on cylinder block lower side, determine new standard bearing to be installed to journal referring to cross-reference table below.

For example, if number stamped on crank web is "4" and alphabet stamped on cylinder block is "A", install new standard bearing painted in "Black" to cylinder block side journal and "Colorless" to lower crankcase side journal.

Main bearing cross-reference table (standard bearing)

MAIN BEARING CROSS-REFERENCE CHART

Application		Stamped number on crank web
Application		4	5	6	7	8	9
Stamped alphabet on lower crankcase	A	Upper: Black	Colorless	Upper: Colorless	Yellow	Upper: Yellow	Blue
	A	Lower: Colorless	Colorless	Lower: Yellow	Yellow	Lower: Blue	Blue
	B	Upper: Colorless	Yellow	Upper: Yellow	Blue	Upper: Blue	Pink
	B	Lower: Yellow	Yellow	Lower: Blue	Blue	Lower: Pink	Pink
	C	Upper: Yellow	Blue	Upper: Blue	Pink	Upper: Pink	Upper: Pink
	C	Lower: Blue	Blue	Lower: Pink	Pink	Lower: Brown	Lower: Brown

Using gauging plastic, check bearing clearance with newly selected standard bearing referring to MAIN BEARING CLEARANCE .
If clearance still exceeds its limit, use next thicker bearing and recheck clearance.

Undersize bearing (0.25 mm)

0.25 mm (0.0098 in.) undersize bearing is available, in five kinds varying in thickness.

To distinguish them, each bearing is painted in the following colors at such position as indicated in figure.

Each color represents the following thickness at the center of bearing.

Undersize main bearing thickness

UNDERSIZE MAIN BEARING THICKNESS SPECIFICATION

Color painted	Bearing thickness
Black & Red	2.6220-2.6250 mm (0.10322-0.10334 in.)
Red only	2.6250-2.6280 mm (0.10335-0.10346 in.)
Yellow & Red	2.6280-2.6310 mm (0.10347-0.10358 in.)
Blue & Red	2.6310-2.6340 mm (0.10359-0.10370 in.)
Pink & Red	2.6340-2.6370 mm (0.10371-0.10382 in.)

Fig 7: Identifying Paint Mark For Bearing Size Identification

Courtesy of SUZUKI OF AMERICA CORP.

If necessary, regrind crankshaft journal and select undersize bearing to use with it as follows.

Regrind journal to the following finished diameter.
Finished journal diameter

64.7380-64.7560 mm (2.54874-2.54944 in.)
Using micrometer, measure reground journal diameter.
Measurement should be taken in two directions perpendicular to each other in order to check for out-of-round.

Fig 8: Measuring Reground Journal Diameter
Courtesy of SUZUKI OF AMERICA CORP.

Using journal diameter measured and alphabets stamped on cylinder block, select undersize bearing referring to cross-reference table below.

Check bearing clearance with newly selected undersize bearing referring to MAIN BEARING CLEARANCE .

Main bearing cross-reference table (undersize bearing)

MAIN BEARING CROSS-REFERENCE CHART

Application		Measured journal diameter
Application		64.7500-64.7560 mm (2.54921-2.54944 in.)	64.7440-64.7499 mm (2.54897-2.54920 in.)	64.7380-64.7439 mm (2.54873-2.54896 in.)
Alphabets stamped on lower crankcase	A	Black & Red	Red only	Yellow & Red
	B	Red only	Yellow & Red	Blue & Red
	C	Yellow & Red	Blue & Red	Pink & Red