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Nissan Pathfinder (2008 year). Manual - part 384

ENGINE UNIT

EM-235

< DISASSEMBLY AND ASSEMBLY >

[VK56DE]

• Install the main bearing caps with the main bearings removed, and

tighten the bolts to the specified torque. Refer to

EM-222, "Disas-

sembly and Assembly"

• Measure inside diameter of main bearing housing.

• If out of the standard, replace cylinder block and main bearing

caps as an assembly.
NOTE:
These components must be replaced as a single unit, because
they were processed together.

PISTON TO CYLINDER BORE CLEARANCE

Cylinder Bore Diameter

• Measure the cylinder bore for wear, out-of-round and taper at six

different points on each cylinder (

″

and

″

directions at

″

and

″

NOTE:
When determining cylinder bore grade, measure cylinder bore at
"B" position.

• If measured value exceeds the repair limit, or if there are scratches and/or seizure on the cylinder inner wall,

hone or bore the inner wall.

• An oversize piston is provided. When using an oversize piston, hone the cylinder so that the clearance

between the piston and cylinder satisfies the standard.

• If oversize piston is used, use it for all cylinders with oversize piston rings.

Piston Skirt Diameter

• Measure piston skirt diameter using suitable tool.

Standard

: 68.944 - 68.968 mm (2.7143 - 2.7153 in)

PBIC1643E

PBIC0123E

Standard diameter:

98.000 - 98.030 mm (3.8583 - 3.8594 in)

Wear limit:

0.20 mm (0.0079 in)

Out-of-round (Difference between

″

and

″

Limit: 0.015 mm (0.0006 in)

Taper limit (Difference between

″

and

″

Limit: 0.010 mm (0.0004 in)

Piston oversize Grade No. 0 (Service)

: 0.20 mm (0.0079 in)

PBIC0124E

Standard

: 97. 980 - 98. 010 mm (3.8575 - 3.8587 in)

PBIC0125E

EM-236

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ENGINE UNIT

• Measure point

″

Piston to Cylinder Bore Clearance

• Calculate by using diameter of the piston skirt and the cylinder bore diameter (direction X, position B).

(Clearance) = (Cylinder bore diameter) – (piston skirt diameter)

• If calculation exceeds the limit, replace piston/piston pin assembly.

Reboring Cylinder Bore

Cylinder bore size is determined by adding piston-to-bore clearance to piston diameter “A”.

Install main bearing caps, and tighten them to the specified torque. Otherwise, cylinder bores may be dis-
torted in final assembly.

Cut the cylinder bores.
NOTE:
• When any cylinder needs boring, all other cylinders must also be bored.
• Do not cut too much out of cylinder bore at one time. Cut only 0.05 mm (0.0020 in) or so in diameter at a

time.

Hone cylinders to obtain the specified piston-to-bore clearance.

Measure finished cylinder bore for out-of-round and taper.
NOTE:
Measurement should be done after cylinder bore cools down.

CRANKSHAFT MAIN JOURNAL DIAMETER

• Measure diameter of crankshaft journals.

• If measurement is out of standard, measure the main bearing oil clearance. Then use the undersize bearing.

Follow the "MAIN BEARING OIL CLEARANCE" procedure.

CRANKSHAFT PIN JOURNAL DIAMETER

Distance from the top

: 39 mm (1.54 in)

KBIA2545E

Standard

: 0.010 - 0.030 mm (0.0004 - 0.0012 in)

Limit

: 0.08 mm (0.0031 in)

Rebored size calculation: D = A +B - C

where,

D: Bored diameter

A: Piston diameter as measured

B: Piston - to - bore clearance (standard value)

C: Honing allowance 0.02 mm (0.0008 in)

Standard

: 63.940 - 63.964 mm (2.5173 - 2.5183 in)

ENGINE UNIT

EM-237

< DISASSEMBLY AND ASSEMBLY >

[VK56DE]

• Measure diameter of crankshaft pin using suitable tool.

• If measurement is out of standard, measure connecting rod bear-

ing oil clearance. Then use undersize bearing. Follow the " CON-
NECTING ROD BEARING OIL CLEARANCE" procedure.

OUT-OF-ROUND AND TAPER OF CRANKSHAFT

• Measure dimensions at four different points as shown on each

journal and pin.

• Out-of-roundness is indicated by the difference in dimension

between

″

and

″

and

″

• Taper is indicated by the difference in dimension between

″

and

″

and

″

• If measured value exceeds the standard, correct or replace crankshaft.
• If corrected, measure the bearing oil clearance of the corrected journal or pin. Then select the main bearing

or connecting rod bearing. Follow the "MAIN BEARING OIL CLEARANCE" or "CONNECTING ROD BEAR-
ING OIL CLEARANCE" procedures.

CRANKSHAFT RUNOUT

• Place a V-block on a precise flat table to support the journals on

both ends of the crankshaft.

• Measure at No. 3 journal using suitable tool.
• While rotating crankshaft, read the movement of the pointer.
• Half of the movement shows the runout.

• If measurement exceeds the limit, replace crankshaft.

CONNECTING ROD BEARING OIL CLEARANCE

Method of Measurement

• Install connecting rod bearings to the connecting rod and cap. Tighten connecting rod bolts to the specified

torque. Refer to

EM-222, "Disassembly and Assembly"

Measure inside diameter of connecting rod bearing.
(Oil clearance) = (Inside diameter of connecting rod bearing) –
(Crankshaft pin diameter)

• If clearance cannot be adjusted within the standard, grind crank-

shaft pin and use undersized bearing. Refer to

EM-241, "How to

Select Piston and Bearing"

Standard

: 53.956 - 53.974 mm (2.1243 - 2.1250 in)

PBIC0127E

Limit

Out-of-round (Difference between

″

and

″

)

: 0.002 mm (0.0001 in)

Taper (Difference between

″

and

″

)

: 0.002 mm (0.0001 in)

PBIC1685E

Limit

: Less than 0.05 mm (0.002 in)

PBIC0129E

Standard

: 0.020 - 0.039 mm (0.0008 - 0.0015 in)

Limit

: 0.055 mm (0.0022 in)

PBIC1642E

EM-238

< DISASSEMBLY AND ASSEMBLY >

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ENGINE UNIT

Method of Using Plastigage

• Remove oil and dust on the crankshaft pin and surfaces of each

bearing completely.

• Cut a plastigage slightly shorter than the bearing width, and place

it in the crankshaft axial direction, avoiding oil holes.

• Install the connecting rod bearings to the connecting rod and con-

necting rod bearing cap, and tighten the connecting rod bolts to the
specified torque.

CAUTION:

Do not rotate crankshaft with plastigage installed.

• Remove the connecting rod bearing cap and bearings. Measure

the plastigage width using the scale on the plastigage bag.
NOTE:
The procedure when the measured value exceeds the repair limit is the same as that described in “Method
of Measurement”.

MAIN BEARING OIL CLEARANCE

Method of Measurement

• Install the main bearings to the cylinder block and main bearing

cap. Measure the main bearing inside diameter with the bearing
cap bolts tightened to the specified torque. Refer to

EM-222, "Dis-

assembly and Assembly"

(Oil clearance) = (Inside diameter of main bearing) – (Crankshaft
journal diameter)

• If measured value exceeds the repair limit, select main bearings referring to the main bearing inside diame-

ter and crankshaft journal diameter, so that the oil clearance satisfies the standard. Refer to

EM-241, "How

to Select Piston and Bearing"

Method of Using Plastigage

• Remove oil and dust on the crankshaft journal and surfaces of

each bearing completely.

• Cut a plastigage slightly shorter than the bearing width, and place

it in crankshaft axial direction, avoiding oil holes.

• Install the main bearings to the cylinder block and main bearing

cap, and tighten the main bearing bolts to the specified torque.

CAUTION:

Do not rotate crankshaft with plastigage installed.

• Remove bearing cap and bearings. Measure plastigage width

using the scale on the plastigage bag.
NOTE:
The procedure when the measured value exceeds the repair limit
is the same as that described in “Method of Measurement”.

CRUSH HEIGHT OF MAIN BEARING

KBIA2550E

Standard:

No. 1 and 5 journals

: 0.001 - 0.011 mm (0.00004 - 0.0004 in)

No. 2, 3 and 4 journals

: 0.007 - 0.017 mm (0.0003 - 0.0007 in)

Limit:

No.1 and 5 journals

: 0.021 mm (0.0008 in)

No. 2, 3 and 4 journals

: 0.027 mm (0.0011 in)

PBIC1644E

KBIA2551E

ENGINE UNIT

EM-239

< DISASSEMBLY AND ASSEMBLY >

[VK56DE]

• When the bearing cap is removed after being tightened to the

specified torque with main bearings installed, the tip end of the
bearing must protrude. Refer to

EM-222, "Disassembly and

Assembly"

for the tightening procedure.

• If standard is not met, replace main bearings.

CRUSH HEIGHT OF CONNECTING ROD BEARING

• When connecting rod bearing cap is removed after being tightened

to the specified torque with the connecting rod bearings installed,
the tip end of the bearing must protrude. Refer to

EM-222, "Disas-

sembly and Assembly"

for tightening procedure.

• If standard is not met, replace connecting rod bearings.

MAIN BEARING CAP BOLT DIAMETER

• Check for bolts (M9 and M12) installed from lower side using the

following procedure.
NOTE:
• Side bolt (M10) is outside the target.
• Figure shows M12 bolt.

• Measure bolt diameter

″

from tip of the bolt to dimension "a".

• Measure bolt diameter

″

from the dimension between tip of the

bolt and dimension

″

as base station to dimension

″

NOTE:
If a narrower part in the threads is determined by visual check,
measure

″

at that point.

• Calculate the difference between

″

and

″

M9 bolt

M12 bolt

• Replace applicable bolts if outside the limit.

CONNECTING ROD BOLT DIAMETER

Standard

: There must be crush height

SEM502G

Standard

: There must be crush height.

PBIC1646E

KBIA2497E

Dimension “a”

: 9 mm (0.35 in)

Dimension “b”

: 15 mm (0.59 in)

Dimension “c”

: 20 mm (0.79 in)

Limit

: 0.10 mm (0.0039 in)

Dimension “a”

: 12 mm (0.47 in)

Dimension “b”

: 55 mm (2.17 in)

Dimension “c”

: 20 mm (0.79 in)

Limit

: 0.15 mm (0.0059 in)

EM-240

< DISASSEMBLY AND ASSEMBLY >

[VK56DE]

ENGINE UNIT

• Measure diameter

″

at position shown.

• When “d” is out of specifications (when it becomes thinner),

replace bolt with a new one.

DRIVE PLATE

• Check drive plate and signal plate for deformation or cracks.

CAUTION:

• Do not disassemble drive plate.
• Do not place drive plate with signal plate facing down.
• When handling signal plate, take care not to damage or

scratch it.

• Handle signal plate in a manner that prevents it from becom-

ing magnetized.

• If anything is found, replace drive plate.

Limit

: 7.75 mm (0.3051 in) or less.

SBIA0286E

PBIC2938E

HOW TO SELECT PISTON AND BEARING

EM-241

< DISASSEMBLY AND ASSEMBLY >

[VK56DE]

HOW TO SELECT PISTON AND BEARING

How to Select Piston and Bearing

INFOID:0000000001282039

DESCRIPTION

*For the service parts, the grade for fitting cannot be selected between a piston pin and a connecting rod.
(Only 0 grade is available.) The information at the shipment from the plant is described as a reference.
• The identification grade stamped on each part is the grade for the dimension measured in new condition.

This grade cannot apply to reused parts.

• For reused or repaired parts, measure the dimension accurately. Determine the grade by comparing the

measurement with the values of each selection table.

• For details of the measurement method of each part, the reuse standards, and the selection method of the

selective fitting parts, follow the applicable procedures.

HOW TO SELECT PISTON

Piston Selective Fitting When New Cylinder Block is Used:

• Check the cylinder bore grade on the bottom face of the cylinder

block, and select the piston of the same grade.

Connecting points

Connecting parts

Selection items

Selection methods

Between cylinder block to
crankshaft

Main bearing

Main bearing grade (bearing
thickness)

Determined by match of cylin-
der block bearing housing
grade (Housing inside diame-
ter) and crankshaft journal
grade (journal outside diameter)

Between crankshaft to connect-
ing rod

Connecting rod bearing

Connecting rod bearing grade
(bearing thickness)

Connecting rod bearing grade =
crankshaft pin grade (pin diam-
eter). No grade exists for inside
diameter of connecting rod
large end.

Between cylinder block to pis-
ton

Piston and piston pin assembly.
The piston is available together
with piston pin as an assembly.

Piston grade (piston diameter)

Piston grade = cylinder bore
grade (diameter of bore)

*Between piston to connecting
rod

—

KBIA2495E

KBIA2496E

EM-242

< DISASSEMBLY AND ASSEMBLY >

[VK56DE]

HOW TO SELECT PISTON AND BEARING

When Cylinder Block is Reused

Measure cylinder block bore diameter.

Determine the bore grade by comparing the measurement with the values under the “Cylinder bore diam-
eter” of the piston selection table. Use oversized piston if the clearance of standard grade piston is outside
the specified value.

Piston Selection Table

Unit: mm (in)

CAUTION:

Oversize must be used in all cylinders when using oversized parts.

NOTE:
• The piston is available together with piston pin as an assembly.
• The piston pin (piston pin bore) grade is provided only for the parts installed at the plant. For service parts,

no grades can be selected (only 0 grade is available).

• Hone the cylinder to obtain specified clearance between the piston and cylinder bore when using an over-

sized piston. Be sure to use the same oversized piston rings.

HOW TO SELECT CONNECTING ROD BEARING

When New Connecting Rod and Crankshaft are Used

Apply the big end inside diameter grade stamped on the con-
necting rod side face to the row in the “Connecting Rod Bearing
Selection Table”.

Apply the pin diameter grade stamped on the crankshaft front
side to the column in the “Connecting Rod Bearing Selection
Table”.

Read the symbol at the cross point of the selected row and col-
umn in the “Connecting Rod Bearing Selection Table”.

Apply the symbol obtained to the "Connecting Rod Bearing
Grade Table" to select.

When Crankshaft and Connecting Rod are Reused

Measure dimensions of the big end inside diameter of the connecting rod and diameter of the crankshaft
pin individually.

Apply the measured dimension to the “Connecting Rod Bearing Selection Table”.

The following steps are the same as in “When New Connecting Rod and Crankshaft are Used”. Follow the
"HOW TO SELECT CONNECTING ROD BEARING" procedure.

Grade number (Mark)

Cylinder bore diameter

98.000-98.010 (3.8583-3.8587)

98.010-98.020 (3.8587-3.8590)

93.020-98.030 (3.8590-3.8594)

Piston diameter

97.980-97.990 (3.8575-3.8579)

97.990-98.000 (3.8579-3.8583)

98.000-98.010 (3.8583-3.8587)

Piston oversize (Service)

: 0.20 mm (0.0079 in)

KBIA2536E

PBIC0110E

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