Mitsubishi Montero (2004+). Manual — part 121

PISTON AND CONNECTING ROD

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ENGINE OVERHAUL

11B-43

CAUTION

Apply ample coat of engine oil to the periphery of the pis-
ton pin and the hole of the connecting rod small end. The
clearance between the piston and the piston pin is a tight
fit at room temperature. Therefore, be sure to heat the pis-
ton before inserting the piston pin. Use care sine the pis-
ton is hot after heating.
3. Heat the piston to approximately 70

°C (158°F).

4. With the front mark of the connecting rod and that of the

piston located on the same side, insert the piston pin.

5. Set the snap ring into the other side of the piston pin hole.

6. Check that the piston moves smoothly.

.

>>B<<OIL RING INSTALLATION
1. Fit the oil ring spacer into the piston ring groove.

NOTE: The side rails and spacer may be installed in either
direction.

AKX01398

70˚C

(158˚F)

AB

AK201080

FRONT MARK 74

AB

FRONT MARK

AKX00716

AK000196AB

SIDE RAIL

SIDE RAIL

SPACER

PISTON AND CONNECTING ROD

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ENGINE OVERHAUL

11B-44

CAUTION

Do not use any piston ring expander when installing the
side rail. If will break the side rail.
2. Install the upper side rail.

To install the side rail, first fit one end of the rail into the
piston groove, then press the remaining portion into the
position by finger. See illustration.

3. Install the lower side rail in the same procedure as described

in step 2.

4. Make sure that the side rails move smoothly in both

directions.

.

>>C<< PISTON RING NO.2/PISTON RING NO.1
INSTALLATION
1. To prevent wrong installation, check the identification mark

of each piston ring. The identification mark is stamped near
the ring gap:

Identification mark

Number 1 ring: 1T
Number 2 ring: 2T

NOTE: Size marks on piston rings are as follows.

2. Using a piston ring expander, fit the number 2 piston ring

into the number 2 groove of piston.
NOTE: Install the piston rings with their identification mark
facing up, to the piston crown side.

3. Install the number 1 piston ring in the same manner as step

2.

.

>>D<< CONNECTING ROD BEARING INSTALLATION
1. Measure the crankshaft pin diameter and confirm its

classification from the following table. In the case of a
crankshaft supplied as a service part, identification
colors/marks of its pins are painted/stamped at the positions
shown in the illustration.

AKX00608

SIDE RAIL END

AB

SIZE

SIZE MARK

Standard

None

0.25 mm (0.010 in) oversize
diameter

25

0.50 mm (0.020 in) oversize
diameter

50

AKX00689

NO.1

NO.2

IDENTIFICATION
MARK

SIZE MARK

IDENTIFICATION MARK

AB

AKX00633

AKX00634

NO.5

LOCATION OF IDENTIFICATION COLOR

NO.2

NO.4

NO.1

NO.3

NO.6

AB

PISTON AND CONNECTING ROD

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ENGINE OVERHAUL

11B-45

2. From the following table, select a bearing whose size is

appropriate for the crankshaft pin outside the diameter.
For example the crankshaft pin outside diameter
identification color is "yellow" and the connecting rod
identification mark is "2," for select a bearing whose
identification color is "green".
If there is no Identification color paint on the crankshaft,
measure the pin outside diameter and select bearing
appropriate for the measured value.

3. Install the selected bearing in the big end and in the cap of

the connecting rod.

.

>>E<< PISTON AND CONNECTING ROD INSTALLATION
1. Liberally coat the circumference of the piston, piston ring,

and oil ring with engine oil.

2. Arrange the piston ring and oil ring gaps (side rail and

spacer) as shown in the illustration.

3. Rotate the crankshaft so that the crank pin is on the center

of the cylinder bore.

CRANKSHAFT PIN OUTSIDE DIAMETER

CONNECTING ROD

BEARING

IDENTIFICATION COLOR SIZE mm (in)

IDENTIFICATION MARK IDENTIFICATION

COLOR

Yellow

54.994

− 55.000

(2.1651

− 2.1654)

0

Pink

1

Red

2

Green

None

54.988

− 54.994

(2.1649

− 2.1651)

0

Red

1

Green

2

Black

White

54.982

− 54.988

(2.1646

− 2.1649)

0

Green

1

Black

2

Brown

AK000449

IDENTIFICATION MARK

AB

AKX00635

IDENTIFICATION
COLOR

AB

AKX00620

UPPER
SIDE RAIL

NO.1

PISTON PIN

TIMING
BELT SIDE

LOWER
SIDE RAIL

NO.2 RING GAP
AND SPACER GAP

AB

PISTON AND CONNECTING ROD

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ENGINE OVERHAUL

11B-46

4. Insert the piston and connecting rod assembly into the

cylinder with the front mark on the piston crown pointing to
the timing belt side.

5. Using a suitable piston ring compressor tool, install the

piston and connecting rod assembly into the cylinder block.

.

>>F<< CONNECTING ROD CAP INSTALLATION
1. Verifying the mark made during disassembly, install the

bearing cap to the connecting rod. If the connecting rod is
new with no index mark, make sure that the bearing locking
notches are on the same side as shown.

2. Make sure that the connecting rod big end side clearance

meets the specification.

Standard value: 0.10

− 0.25 mm (0.004 − 0.009 inch)

Limit: 0.4 mm (0.02 inch)

.

>>G<< CONNECTING ROD CAP NUT INSTALLATION
1. The connecting rod bolts should be examined before reuse.

If the bolt threads are damaged, the bolt should be replaced.
Hand-thread the nut to the full length of the bolt threads. If
the nut does not run down smoothly, the bolt should be
replaced.

AK201081AB

FRONT MARK

AKX00721

AKX00735

CYLINDER NO.

NOTCHES

AB

AK201530