Nissan Frontier. Manual — part 727
ENGINE UNIT
EM-97
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• Measure the outer diameter of crankshaft pin journal with a micrometer.
• If out of the standard, measure the connecting rod bearing oil clearance. Then use undersize bearing. Refer
OUT-OF-ROUND AND TAPER OF CRANKSHAFT
• Measure the dimensions at four different points as shown on each
main journal and pin journal with a micrometer.
• Out-of-round is indicated by the difference in dimensions between
(X) and (Y) at (A) and (B).
• Taper is indicated by the difference in dimension between (A) and
(B) at (X) and (Y).
• If the measured value exceeds the limit, correct or replace crankshaft.
• If corrected, measure the bearing oil clearance of the corrected main journal and/or pin journal. Then select
main bearing and/or connecting rod bearing. Refer to
.
CRANKSHAFT RUNOUT
• Place a V-block on a precise flat table to support the journals on
the both end of crankshaft.
• Place a dial indicator straight up on the No. 3 journal.
• While rotating crankshaft, read the movement of the pointer on the
dial indicator. (Total indicator reading)
• If it exceeds the limit, replace crankshaft.
CONNECTING ROD BEARING OIL CLEARANCE
Method by Calculation
• Install connecting rod bearings to connecting rod and cap, and tighten connecting rod bolts to the specified
EM-81, "Disassembly and Assembly"
for tightening procedure.
• Measure the inner diameter of connecting rod bearing with an
inside micrometer.
(Bearing oil clearance) = (Connecting rod bearing inner diameter)
– (Crankshaft pin journal diameter)
• If the clearance exceeds the limit, select proper connecting rod
bearing according to connecting rod big end diameter and crank-
shaft pin journal diameter to obtain the specified bearing oil clear-
ance. Refer to
EM-101, "How to Select Piston and Bearing"
Method of Using Plastigage
• Remove engine oil and dust on crankshaft pin and the 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 connecting rod bearings to connecting rod and cap, and tighten connecting rod bolts to the specified
EM-81, "Disassembly and Assembly"
for the tightening procedure.
Standard: 44.956 - 44.974 mm (1.7699-1.7706 in) dia.
Limit:
Out-of-round [Difference between (X) and (Y)]
: 0.0025 mm (0.0001 in)
Taper [Difference between (A) and (B)]
: 0.0025 mm (0.0001 in)
PBIC2203E
Limit
: 0.05 mm (0.0020 in)
PBIC2541E
Standard
: 0.035 - 0.045 mm (0.0014 - 0.0018 in)
PBIC1642E
EM-98
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ENGINE UNIT
CAUTION:
Do not rotate crankshaft.
• Remove connecting rod cap and bearing, and using the scale on
the plastigage bag, measure the plastigage width.
NOTE:
The procedure when the measured value exceeds the limit is
same as that described in the “Method by Calculation”.
MAIN BEARING OIL CLEARANCE
Method by Calculation
• Install main bearings to cylinder block and lower cylinder block, and tighten lower cylinder block bolts to the
specified torque. Refer to
EM-81, "Disassembly and Assembly"
• Measure the inner diameter of main bearing with a bore gauge.
(Bearing oil clearance) = (Main bearing inner diameter) – (Crank-
shaft main journal diameter)
• If the clearance exceeds the limit, select proper main bearing according to main bearing inner diameter and
crankshaft main journal diameter to obtain the specified bearing oil clearance. Refer to
.
Method of Using Plastigage
• Remove engine oil and dust on crankshaft main journal and the 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 main bearings to cylinder block and lower cylinder block, and tighten lower cylinder block bolts to the
specified torque. Refer to
EM-81, "Disassembly and Assembly"
CAUTION:
Do not rotate crankshaft.
• Remove lower cylinder block and bearings, and using the scale on
the plastigage bag, measure the plastigage width.
NOTE:
The procedure when the measured value exceeds the limit is
same as that described in the “Method by Calculation”.
MAIN BEARING CRUSH HEIGHT
PBIC1149E
Standard:
No. 1, 3 and 5 journals
: 0.028 - 0.042 mm (0.0011 - 0.0017 in)
No. 2 and 4 journals
: 0.041 - 0.056 mm (0.0016 - 0.0022 in)
Limit
: 0.1 mm (0.004 in)
PBIC2204E
PBIC1149E
ENGINE UNIT
EM-99
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• When lower cylinder block is removed after being tightened to the
specified torque with main bearings installed, the tip end of bearing
must protrude. Refer to
EM-81, "Disassembly and Assembly"
the tightening procedure.
• If the standard is not met, replace main bearings.
CONNECTING ROD BEARING CRUSH HEIGHT
• When connecting rod bearing cap is removed after being tightened
to the specified torque with connecting rod bearings installed, the
tip end of bearing must protrude. Refer to
for the tightening procedure.
• If the standard is not met, replace connecting rod bearings.
LOWER CYLINDER BLOCK BOLT OUTER DIAMETER
• Perform only with M10 bolts.
• Measure the outer diameters [(d
1)
, (d
2
)] at two positions as shown.
• If reduction appears in (A) range, regard it as (d
2)
.
• If it exceeds the limit (a large difference in dimensions), replace
lower cylinder block bolt with a new one.
CONNECTING ROD BOLT OUTER DIAMETER
• Measure the outer diameter (d) at position as shown.
• If reduction appears in a position other than (d), regard it as (d).
• When (d) falls below the limit (when it becomes thinner), replace
connecting rod bolt with a new one.
MOVEMENT AMOUNT OF FLYWHEEL (M/T MODELS)
CAUTION:
Do not disassemble double mass flywheel.
Movement Amount of Thrust (Fore-and-Aft) Direction
• Measure the movement amount of thrust (fore-and-aft) direction when 100 N (10.2 kg, 22 lb) force is added
at the portion of 125 mm (4.92 in) radius from the center of flywheel.
Standard: There must be crush height.
SEM502G
Standard: There must be crush height.
PBIC1646E
Limit [(d
1)
– (d
2
)]: 0.13 mm (0.0051 in)
PBIC0911E
Limit: 7.75 mm (0.3051 in)
PBIC0912E
Standard
: 1.3 mm (0.051 in) or less
EM-100
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ENGINE UNIT
• If measured value is out of the standard, replace flywheel.
Movement Amount in Radial (Rotation) Direction
Check the movement amount of radial (rotation) direction with the following procedure:
1. Install a bolt to clutch cover mounting hole, and place a torque wrench on the extended line of the flywheel
center line.
• Tighten bolt at a force of 9.8 N·m (1.0 kg-m, 87 in-lb) to keep it from loosening.
2. Put a mating mark on circumferences of the two flywheel
masses without applying any load (Measurement standard
points).
3. Apply a force of 9.8 N·m (1.0 kg-m, 87 in-lb) in each direction,
and mark the movement amount on the mass on the transmis-
sion side.
4. Measure the dimensions of movement amounts (A) and (B) on
circumference of flywheel on the transmission side.
• If measured value is out of the standard, replace flywheel.
DRIVE PLATE (A/T MODELS)
• 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.
Standard: 44.3 mm (1.744 in) or less.
PBIC1263E
PBIC2938E
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