Infiniti QX56 (Z62). Manual - part 669

EM-116

< UNIT DISASSEMBLY AND ASSEMBLY >

CYLINDER BLOCK

CONNECTING ROD SIDE CLEARANCE

• Measure the side clearance between connecting rod and crank-

shaft arm with a feeler gauge (A).

• If the measured value exceeds the limit, replace connecting rod,

and measure again. If it still exceeds the limit, replace crankshaft
also.

PISTON TO PISTON PIN OIL CLEARANCE

Piston Pin Hole Diameter

Measure the inner diameter of piston pin hole with an inside
micrometer (A).

Piston Pin Outer Diameter

Measure the outer diameter of piston pin with a micrometer (A).

Piston to Piston Pin Oil Clearance

(Piston to piston pin oil clearance) = (Piston pin hole diameter) – (Piston pin outer diameter)

• If the calculated value is out of the standard, replace piston and piston pin assembly.
• When replacing piston and piston pin assembly, refer to 

EM-125, "Description"

.

NOTE:
Piston is available together with piston pin as assembly.

PISTON RING SIDE CLEARANCE

Standard and limit

: Refer to 

EM-137, "Cylinder Block"

.

JPBIA2476ZZ

Standard

: Refer to 

EM-137, "Cylinder Block"

.

JPBIA0217ZZ

Standard

: Refer to 

EM-137, "Cylinder Block"

.

JPBIA0218ZZ

Standard

: Refer to 

EM-137, "Cylinder Block"

.

CYLINDER BLOCK

EM-117

< UNIT DISASSEMBLY AND ASSEMBLY >

C

D

E

F

G

H

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A

EM

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• Measure the side clearance of piston ring (1) and piston ring

groove with a feeler gauge (C).

• If the measured value exceeds the limit, replace piston ring, and

measure again. If it still exceeds the limit, replace piston also.

PISTON RING END GAP

• Check that the cylinder bore inner diameter is within the specifica-

tion.

• Lubricate with new engine oil to piston (1) and piston ring (2), and

then insert piston ring until middle of cylinder with piston, and mea-
sure the piston ring end gap with a feeler gauge (B).

• If the measured value exceeds the limit, replace piston ring, and

measure again. If it still exceeds the limit, re-bore cylinder and use
oversize piston and piston rings.

CONNECTING ROD BEND AND TORSION

• Check with a connecting rod aligner.

• If it exceeds the limit, replace connecting rod assembly.

CONNECTING ROD BIG END DIAMETER

A

:  OK

B

:  NG

Standard and limit

: Refer to 

EM-137, "Cylinder Block"

.

JPBIA2276ZZ

A

: Press-fit

Standard and limit

: Refer to 

EM-137, "Cylinder Block"

.

JPBIA2277ZZ

A

:  Bend

B

:  Torsion

C

: Feeler gauge

Bend limit 

: Refer to 

EM-137, 

"Cylinder Block"

.

Torsion limit

JPBIA0221ZZ

EM-118

< UNIT DISASSEMBLY AND ASSEMBLY >

CYLINDER BLOCK

• Install connecting rod bearing cap without installing connecting rod

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

EM-107, "Disassembly and Assembly"

 for the tightening

procedure.

• Measure the inner diameter of connecting rod big end with an

inside micrometer.

• If out of the standard, replace connecting rod assembly.

CONNECTING ROD BUSHING OIL CLEARANCE

Connecting Rod Bushing Inner Diameter

Measure the inner diameter of connecting rod bushing with an inside
micrometer (A).

Piston Pin Outer Diameter

Measure the outer diameter of piston pin with a micrometer (A).

Connecting Rod Bushing Oil Clearance

(Connecting rod bushing oil clearance) = (Connecting rod bushing inner diameter) – (Piston pin outer diame-
ter)

• If the calculated value exceeds the limit, replace connecting rod assembly and/or piston and piston pin

assembly.

• If replacing piston and piston pin assembly, refer to 

EM-125, "Description"

.

• If replacing connecting rod assembly, refer to 

EM-126, "Connecting Rod Bearing"

 to select the connecting

rod bearing.

CYLINDER BLOCK DISTORTION

• Using a scraper, remove gasket on the cylinder block surface, and also remove engine oil, scale, carbon, or

other contamination. 

CAUTION:

Be careful not to allow gasket flakes to enter engine oil or engine coolant passages.

1

: Connecting rod

Standard

: Refer to 

EM-137, "Cylinder Block"

.

JPBIA0222ZZ

Standard

: Refer to 

EM-137, "Cylinder Block"

.

JPBIA0223ZZ

Standard

: Refer to 

EM-137, "Cylinder Block"

.

JPBIA0218ZZ

Standard and limit

: Refer to 

EM-137, "Cylinder Block"

.

CYLINDER BLOCK

EM-119

< UNIT DISASSEMBLY AND ASSEMBLY >

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D

E

F

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• Measure the distortion on the cylinder block upper face at some

different points in six directions (C), (D), (E), (F), (G) and (H) with a
straightedge (A) and a feeler gauge (B).

• If it exceeds the limit, replace cylinder block.

MAIN BEARING HOUSING INNER DIAMETER

• Install main bearing cap (2) without installing main bearings, and

tighten main bearing cap bolts to the specified torque. Refer to 

EM-

107, "Disassembly and Assembly"

 for the tightening procedure.

• Measure the inner diameter of main bearing housing with a bore

gauge.

• If out of the standard, replace cylinder block (1) and main bearing

cap as assembly.
NOTE:
Cylinder block cannot be replaced as a single part, because it is
machined together with main bearing cap.

PISTON TO CYLINDER BORE CLEARANCE

Cylinder Bore inner Diameter 

• Using a bore gauge, measure cylinder bore for wear, out-of-round

and taper at six different points on each cylinder. [(A) and (B) direc-
tions at (C), (D) and (E)] is in longitudinal direction of engine.

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

hone or re-bore the inner wall. 

• Oversize piston is provided. When using oversize piston, re-bore cylinder so that the clearance of the piston-

to-cylinder bore satisfies the standard.

CAUTION:

When using oversize piston, use oversize pistons for all cylinders with oversize piston rings.

Piston Skirt Diameter

Limit

: Refer to 

EM-137, "Cylinder Block"

.

JPBIA0224ZZ

Standard

: Refer to 

EM-137, "Cylinder Block"

.

JPBIA0225ZZ

f

: 10 mm (0.39 in)

g

: 60 mm (2.36 in)

h

: 120 mm (4.72 in)

JPBIA2279ZZ

Wear limit:

Refer to 

EM-137, "Cylinder Block"

.

Out-of-round (Difference between “A” and “B”):

Taper limit (Difference between “C” and “E”):

Oversize (O/S)

: 0.2 mm (0.008 in)