Nissan Frontier. Instruction — part 726
ENGINE UNIT
EM-93
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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
• Install connecting rod bearing cap without connecting rod bearing installed, and tightening connecting rod
bolts to the specified torque. Refer to
EM-81, "Disassembly and Assembly"
• 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.
Piston Pin Outer Diameter
Bend:
Limit: 0.15 mm (0.0059 in) per 100 mm (3.94 in) length
Torsion:
Limit: 0.30 mm (0.0118 in) per 100 mm (3.94 in) length
PBIC2077E
Standard: 48.000 - 48.013 mm (1.8898 - 1.8903 in)
PBIC1641E
Standard: 20.000 - 20.012 mm (0.7874 - 0.7879 in)
PBIC0120E
EM-94
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ENGINE UNIT
Measure the outer diameter of piston pin with a micrometer.
Connecting Rod Bushing Oil Clearance
(Connecting rod bushing oil clearance) = (Connecting rod bushing inner diameter) – (Piston pin outer diame-
ter)
• If the measured value is out of the standard, replace connecting rod assembly and/or piston and piston pin
assembly.
• If replacing piston and piston pin assembly. Refer to
.
• If replacing connecting rod assembly. Refer to
to select connecting rod bearing.
Factory installed parts grading:
• Service parts apply only to grade “0”.
Unit: mm (in)
*: After installing in connecting rod.
CYLINDER BLOCK DISTORTION
• Remove gasket on the cylinder block surface, and also remove engine oil, scale, carbon, or other contami-
nation; using suitable tool.
CAUTION:
Do not allow any debris to enter engine oil or engine coolant passages.
Standard: 19.989 - 20.001 mm (0.7870 - 0.7874 in)
PBIC0117E
Standard: 0.005 - 0.017 mm (0.0002 - 0.0007 in)
PBIC2196E
Grade
0
1
Connecting rod bushing
inner diameter
*
20.000 - 20.006
(0.7874 - 0.7876)
20.006 - 20.012
(0.7876 - 0.7879)
Piston pin hole diameter
19.993 - 19.999
(0.7871 - 0.7874)
19.999 - 20. 005
(0.7874 - 0.7876)
Piston pin outer diameter
19.989 - 19.995
(0.7870 - 0.7872)
19.995 - 20.001
(0.7872 - 0.7874)
PBIC3019E
ENGINE UNIT
EM-95
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• Measure the distortion on the cylinder block upper face at some
different points in six directions with straightedge and feeler gauge.
• If it exceeds the limit, replace cylinder block and lower cylinder
block assembly.
NOTE:
Cylinder block cannot be replaced as a single part, because it is
machined together with lower cylinder block.
MAIN BEARING HOUSING INNER DIAMETER
• Install lower cylinder block without main bearings installed, and
tighten lower cylinder block bolts to the specified torque. Refer to
EM-81, "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 and lower cylinder
block assembly.
NOTE:
Cylinder block cannot be replaced as a single part, because it is
machined together with lower cylinder block.
PISTON TO CYLINDER BORE CLEARANCE
Cylinder Bore Inner Diameter
• Using a bore gauge, measure the cylinder bore for wear, out-of-
round and taper at six different points on each cylinder. [(X) and (Y)
directions at (A), (B) and (C)] [(Y) is in longitudinal direction of the
engine].
NOTE:
When determining cylinder bore grade, measure cylinder bore at
(B) position.
• 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 cylinder inner wall.
Piston Skirt Diameter
Limit: 0.1 mm (0.004 in)
PBIC0121E
Standard: 58.944 - 58.968 mm (2.3206 - 2.3216 in)
PBIC2012E
Standard inner diameter:
89.010 - 89.030 mm (3.5043 - 3.5051 in)
Wear limit:
0.2 mm (0.008 in)
Out-of-round [Difference between (X) and (Y)]:
0.015 mm (0.0006 in)
Taper limit [Difference between (A) and (C)]:
0.01 mm (0.0004 in)
SBIA0284E
EM-96
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ENGINE UNIT
Measure the outer diameter of piston skirt with a micrometer.
Piston to Cylinder Bore Clearance
Calculate by piston skirt diameter and cylinder bore inner diameter [direction (X), position (B)].
(Clearance) = (Cylinder bore inner diameter) – (Piston skirt diameter)
• If it exceeds the limit, replace piston and piston pin assembly. Refer to
EM-101, "How to Select Piston and
Re-boring Cylinder Bore
1. Cylinder bore size is determined by adding piston to cylinder bore clearance to piston skirt diameter.
2. Install lower cylinder block, and tighten bolts to the specified torque. Otherwise, cylinder bores may be dis-
torted in final assembly. Refer to
EM-81, "Disassembly and Assembly"
for the tightening procedure.
3. Cut 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 a time. Cut only 0.05 mm (0.0020 in) or so in diameter at a
time.
4. Hone cylinders to obtain the specified piston to cylinder bore clearance.
5. Measure the finished cylinder bore for out-of-round and taper.
NOTE:
Measurement should be done after cylinder bore cools down.
CRANKSHAFT MAIN JOURNAL DIAMETER
• Measure the outer diameter of crankshaft main journals with a
micrometer.
• If out of the standard, measure the main bearing oil clearance.
Then use undersize bearing. Refer to
CRANKSHAFT PIN JOURNAL DIAMETER
Measure point
: Distance from the top 42.98 mm (1.692 in)
Standard
: 88.990 - 89.010 mm (3.5035 - 3.5043 in)
PBIC0125E
Standard
: 0.010 - 0.030 mm (0.0004 - 0.0012 in)
Limit
: 0.08 mm (0.0031 in)
Re-bored size calculation: D = A + B - C
where,
D: Bored diameter
A: Piston diameter as measured
B: Piston - to - cylinder bore clearance (standard value)
C: Honing allowance 0.02 mm (0.0008 in)
Standard: 54.955 - 54.979 mm (2.1636 - 2.1645 in) dia.
PBIC0270E
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