INFINITI QX56 2008 Factory Service Manual

EM-98
< DISASSEMBLY AND ASSEMBLY >
ENGINE UNIT
Method of Using Plastigage
• Remove oil and dust on the crankshaft pin and surfaces of eachbearing 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 beari ngs 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 bear ing 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-82, "
Disas-
sembly 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-101, "
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 descri bed 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
Revision: March 2010 2008 QX56

ENGINE UNITEM-99
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• 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-82, "
Disassembly and Assem-
bly" 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-82, "
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 ″ d1″ from tip of the bolt to dimension "a".
• Measure bolt diameter ″d2″ from the dimension between tip of the
bolt and dimension ″b ″ as base station to dimension ″c″ .
NOTE:
If a narrower part in the threads is determined by visual check,
measure ″d2″ at that point.
• Calculate the difference between ″d1″ and ″d2″ .
M9 bolt
M12 bolt
• Replace applicable bolts if outside the limit.
CONNECTING ROD BOLT DIAMETER
• Measure diameter ″d ″ at position shown.
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)
Revision: March 2010
2008 QX56

EM-100
< DISASSEMBLY AND ASSEMBLY >
ENGINE UNIT
• When “d” is out of specifications (when it becomes thinner),
replace bolt with a new one.
Limit : 7.75 mm (0.3051 in) or less.
SBIA0286E
Revision: March 2010 2008 QX56

HOW TO SELECT PISTON AND BEARINGEM-101
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HOW TO SELECT PISTON AND BEARING
How to Select Piston and BearingINFOID:0000000001538834
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 sh
ipment 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 dimens ion 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 itemsSelection 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
Revision: March 2010
2008 QX56

EM-102
< DISASSEMBLY AND ASSEMBLY >
HOW TO SELECT PISTON AND BEARING
When Cylinder Block is Reused
1. Measure cylinder block bore diameter.
2. Determine the bore grade by comparing the measurement with the values under the “Cylinder bore diam-
eter” of the piston selection table.
Piston Selection Table
Unit: mm (in)
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.
HOW TO SELECT CONNECTING ROD BEARING
When New Connecting Rod and Crankshaft are Used
1. 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”.
2. Apply the pin diameter grade stamped on the crankshaft front side to the column in the “Connecting Rod Bearing Selection
Table”.
3. Read the symbol at the cross point of the selected row and col-
umn in the “Connecting Rod Bearing Selection Table".
4. Apply the symbol obtained to the "Connecting Rod Bearing Grade Table" to select.
When Crankshaft and Connecting Rod are Reused
1. Measure dimensions of the big end inside diameter of the connecting rod and diameter of the crankshaftpin individually.
2. Apply the measured dimension to the “Connecting Rod Bearing Selection Table”.
3. 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) 12 3
Cylinder bore diameter 98.000-98.010 (3.8583-3.8587) 98.010-98.020 (3.8587-3.8590) 98.020-98.030 (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)
KBIA2536E
PBIC0110E
Revision: March 2010 2008 QX56

HOW TO SELECT PISTON AND BEARINGEM-103
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Connecting Rod Bearing Selection Table
Connecting Rod Bearing Grade Table.
Undersize Bearings Usage Guide
• When the specified oil clearance is not obtained with standard size connecting rod bearings, use undersize
(US) bearings.
• When using undersize bearing, measure the bearing inside diameter with the bearing installed, and grind the
crankshaft pin so that the oil clearance satisfies the standard.
Bearing undersize table
Unit: mm (in)
CAUTION:
In grinding the crankshaft pin to use undersize bearings, keep
the fillet R (All crankshaft pins).
HOW TO SELECT MAIN BEARING
When New Cylinder Block and Crankshaft are Used
1. Apply the main bearing housing grade on the bottom face of the cylinder block to the row in "Main Bearings Selection Table".
KBIA2538E
Grade number Thickness “T” mm (in) Identification color (mark)
0 1.500 - 1.503 (0.0591 - 0.0592) Black
1 1.503 - 1.506 (0.0592 - 0.0593) Brown
2 1.506 - 1.509 (0.0593 - 0.0594) Green
3 1.509 - 1.512 (0.0594 - 0.0595) Yellow
UndersizeThickness
0.25 (0.0098) 1.627 - 1.635 (0.0641 - 0.0644)
Fillet R : 1.5 - 1.7 mm (0.059 - 0.067 in)
PBIC0111E
KBIA2495E
Revision: March 2010 2008 QX56

EM-104
< DISASSEMBLY AND ASSEMBLY >
HOW TO SELECT PISTON AND BEARING
2. Apply the journal diameter grade on the crankshaft front to thecolumn in "Main Bearings Selection Table".
3. Read the symbol at the cross point of the selected row and column in the "Main Bearings Selection Table".
CAUTION:
• Initial clearance for No. 1, 5 journal and No. 2, 3, 4 journal is different. Use two different selection
lists for each part.
• No. 1, 5 journal and No. 2, 3, 4 journal have the same signs but different measures. Do not con-
fuse them.
4. Apply the symbol to the "Main Bearings Grade Table" to select. NOTE:
• Grade list applies to all journals.
• Service parts are available as a set of both upper and lower.
When Cylinder Block and Crankshaft are Reused
1. Measure the inside diameter of the cylinder block main bearings housing and the outside diameter of the
crankshaft journal.
2. Apply measurement in above step 1 to "Main Bearings Selection Table".
3. The following steps are same as in “When New Cylinder Block and Crankshaft are Used”. Follow the "HOW TO SELECT MAIN BEARING" procedure.
PBIC0110E
Revision: March 2010 2008 QX56

HOW TO SELECT PISTON AND BEARINGEM-105
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Main Bearings Selection Table (No. 1 and No. 5 journal)
WBIA0608E
Revision: March 2010
2008 QX56

EM-106
< DISASSEMBLY AND ASSEMBLY >
HOW TO SELECT PISTON AND BEARING
Main Bearings Selection Table (No. 2, 3 and 4 journal)
Main Bearings Grade Table (All Journals)
Unit: mm (in)
WBIA0609E
Grade number* UPR/LWRThickness Identification color Remarks
0 —2.483 - 2.486 (0.0978 - 0.0979) Black
Grade is the same for upper
and lower bearings.
1
—2.486 - 2.489 (0.0979 - 0.0980) Brown
2 —2.489 - 2.492 (0.0980 - 0.0981) Green
3 —2.492 - 2.495 (0.0981 - 0.0982) Yellow
4 —2.495 - 2.498 (0.0982 - 0.0983) Blue
5 —2.498 - 2.501 (0.0983 - 0.0985) Pink
6 —2.501 - 2.504 (0.0985 - 0.0986) Purple
7 —2.504 - 2.507 (0.0986 - 0.0987) White
8 —2.507 - 2.510 (0.0987 - 0.0988) Red
Revision: March 2010 2008 QX56

HOW TO SELECT PISTON AND BEARINGEM-107
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*: Always check with the Parts Department for the latest parts information.
Use Undersize Bearing Usage Guide
• Use undersize (US) bearing when the oil clearance with
standard size main bearing is not within specifica-
tion.
• When using undersize (US) bearing, measure the inside di ameter of the bearing installed and grind the jour-
nal until the oil clearance falls within specification.
Bearing undersize table
Unit: mm (in)
CAUTION:
Do not damage fillet R when grinding crankshaft journal in
order to use undersized bearing (All journals).
01 UPR
2.483 - 2.486 (0.0978 - 0.0979) Black
Grade and color are different
for upper and lower bearings.
LWR
2.486 - 2.489 (0.0979 - 0.0980) Brown
12 UPR
2.486 - 2.489 (0.0979 - 0.0980) Brown
LWR 2.489 - 2.492 (0.0980 - 0.0981) Green
23 UPR
2.489 - 2.492 (0.0980 - 0.0981) Green
LWR 2.492 - 2.495 (0.0981 - 0.0982) Yellow
34 UPR
2.492 - 2.495 (0.0981 - 0.0982) Yellow
LWR 2.495 - 2.498 (0.0982 - 0.0983) Blue
45 UPR
2.495 - 2.498 (0.0982 - 0.0983) Blue
LWR 2.498 - 2.501 (0.0983 - 0.0985) Pink
56 UPR
2.498 - 2.501 (0.0983 - 0.0985) Pink
LWR 2.501 - 2.504 (0.0985 - 0.0986) Purple
67 UPR
2.501 - 2.504 (0.0985 - 0.0986) Purple
LWR 2.504 - 2.507 (0.0986 - 0.0987) White
78 UPR
2.504 - 2.507 (0.0986 - 0.0987) White
LWR 2.507 - 2.510 (0.0987 - 0.0988) Red
UndersizeThickness
0.25 (0.0098) 2.618 - 2.626 (0.1031 - 0.1034)
Fillet R : 1.5 - 1.7 mm (0.059 - 0.067 in)
PBIC0111E
Revision: March 2010 2008 QX56