Suzuki Grand Vitara JB627. Manual — part 97

1D-69 Engine Mechanical:

Main Bearings Inspection

S6JB0B1406046

Main Bearing General Information

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.

• 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.

1) Remove lower crankcase.
2) Clean bearings and main journals.
3) Place a piece of gauging plastic (1) to full width of

bearing (parallel to crankshaft) on journal, avoiding
oil hole.

4) Install lower crankcase to cylinder block without

applying sealant referring to “Main Bearings,
Crankshaft and Cylinder Block Removal and
Installation”.

5) 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.)

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Engine Mechanical: 1D-70

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.

1) 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

2) 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

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.)

1. Crankshaft

2. Crank web

4
5
6
7

1

2

I5GEB1141001-01

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.)

1. Crankshaft pulley side

4. No.2 bearing

2. Stamped alphabets

5. No.3 bearing

3. No.1 bearing

6. No.4 bearing

2

1

3

4

5

6

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1D-71 Engine Mechanical:

3) 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

4) 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)

5) 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.

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.)

1. Paint

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Stamped number on crank web

4

5

6

7

8

9

Stamped

alphabet on

lower crankcase

A

Upper: Black

Lower: Colorless

Colorless

Upper: Colorless

Lower: Yellow

Yellow

Upper: Yellow

Lower: Blue

Blue

B

Upper: Colorless

Lower: Yellow

Yellow

Upper: Yellow

Lower: Blue

Blue

Upper: Blue
Lower: Pink

Pink

C

Upper: Yellow

Lower: Blue

Blue

Upper: Blue
Lower: Pink

Pink

Upper: Pink

Lower: Brown

Upper: Pink

Lower: Brown

Engine Mechanical: 1D-72

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

• If necessary, regrind crankshaft journal and select

undersize bearing to use with it as follows.
a. Regrind journal to the following finished diameter.

Finished journal diameter
64.7380 – 64.7560 mm (2.54874 – 2.54944 in.)

b. 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.

c. 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)

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.)

1. Paint

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Measured journal diameter

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

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