Nissan Frontier D22. Manual — part 683
CYLINDER HEAD
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VALVE SEATS
Check valve seats for pitting at contact surface. Resurface or
replace if excessively worn.
●
Before repairing the valve seats, check the valves and valve
guides for wear as shown. If they are worn, replace them. Then
resurface the valve seat as necessary.
●
Use both hands to resurface the valve seat uniformly using a
suitable tool, as shown.
REPLACING VALVE SEAT
1.
Bore out the old seat until it collapses. Boring should not con-
tinue beyond the bottom face of the seat recess in the cylinder
head. Set the machine depth stop to prevent damage.
2.
Ream the cylinder head valve seat recess.
CAUTION:
Use the valve guide center for a reference point for reaming so the valve and valve seat will have
the correct fit.
3.
Heat the cylinder head to 120
° - 140°C (248° - 284°F) in heated
oil.
SBIA0322E
SEM302D
SEM795A
Reaming bore for service valve seat
Oversize
: 0.5 mm (0.020 in)
Intake
: 38.000 - 38.016 mm (1.4961 - 1.4967 in)
Exhaust
: 32.700 - 32.716 mm (1.2874 - 1.2880 in)
SEM008A
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CYLINDER HEAD
4.
Press fit valve seat until it seats on the bottom of the recess.
5.
Cut or grind valve seat using suitable tool to the specified dimen-
sions.
6.
After cutting, lap valve seat with abrasive compound.
7.
Check the valve seat dimensions. Refer to
8.
Use a depth gauge to measure the distance between the mount-
ing surface of the cylinder head spring seat and the valve stem
end. If the distance is shorter than specified, repeat step 5
through 7 above, to adjust it. If it is longer, replace the valve seat
with a new one.
VALVE DIMENSIONS
Check dimensions of each valve. Refer to
. When
valve head has been worn down to less than the margin thickness
"T", replace the valve. Do not grind the valve stem more than the
grinding limit specification.
VALVE SPRING
Squareness
1.
Measure the spring out-of-square dimension “S” as shown.
2.
If the out-of-square measurement exceeds the limit, replace the
spring.
Seat face “
α” : 45° 15′ - 45° 45′ degrees
Contacting width “W”
Intake
: 1.48 - 1.63 mm (0.0583 - 0.0642 in)
Exhaust
: 1.8 - 2.0 mm (0.071 - 0.079 in)
SEM892B
Valve seat resurface limit - height “L”
Intake
: 42.02 - 42.52 mm (1.6543 - 1.6740 in)
Exhaust
: 42.03 - 42.53 mm (1.6547 - 1.6744 in)
SEM621F
Margin thickness "T"
: 0.5 mm (0.020 in)
Valve stem tip grinding limit
: 0.2 mm (0.008 in)
SEM188A
Out-of-square “S”
: less than 2.2 mm (0.087 in)
SEM288A
CYLINDER HEAD
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Pressure
1.
Check the valve spring pressure at the specified spring height.
2.
If not within specification, replace the spring.
VALVE LIFTER AND ADJUSTING SHIM
1.
Visually check the valve lifter and adjusting shim contact and
sliding surfaces for wear and scratches.
2.
Check the diameter of the valve lifter as shown.
3.
Check the diameter of the valve lifter guide bore as shown.
4.
If the measurements exceed the standard diameter or clearance, replace valve lifter or cylinder head as
necessary.
Pressure
: N (kg, lb) at height mm (in)
Standard
: 418.0 (42.6, 93.9) at 29.17 (1.1484)
Limit
: 393.0 (40.1, 88.4) at 29.17 (1.1484)
EM113
AEM499
AEM502
SEM303D
Valve lifter outer diameter
: 33.960 - 33.975 mm (1.3370 - 1.3376 in)
Lifter guide bore diameter
: 34.000 - 34.021 mm (1.3386 - 1.3394 in)
Valve lifter to valve lifter guide clearance
: 0.025 - 0.061 mm (0.0010 - 0.0024 in)
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CYLINDER HEAD
Assembly
EBS00GSK
1.
Install valve component parts.
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Always use new valve oil seal. Refer to
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Before installing valve oil seal, install valve spring seat.
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Install outer valve spring (uneven pitch type) with its narrow
pitch side toward cylinder head side.
2.
After installing the valve component parts, tap valve stem tip
with a plastic hammer to assure a proper fit.
Installation
EBS00GSL
1.
Tighten the cylinder head bolts in the numerical order as shown,
using the five step procedure:
NOTE:
If an angle wrench is not available, mark all of the cylinder head
bolts on the side facing engine front. Then turn each cylinder
head bolt to the specified angle.
2.
Set camshafts and camshaft brackets.
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Set the dowel pins of both the intake and exhaust camshafts at 12 o'clock position when installing the
camshafts.
3.
Tighten the camshaft bracket bolts in the order shown using two
steps:
●
Apply new engine oil to bolt threads and seat surfaces.
4.
Install upper timing chain and idler sprocket. Refer to
SEM638B
SEM275D
Cylinder head bolt tightening steps:
Step "a"
: 29 N·m (3.0 kg-m, 22 ft-lb)
Step "b"
: 79 N·m (8.1 kg-m, 59 ft-lb)
Step "c"
: Loosen all bolts completely.
Step "d"
: 25 - 34 N·m (2.5 - 3.5 kg-m, 18 - 25 ft-lb)
Step "e"
: 86
° - 91° degrees clockwise
SEM276D
Camshaft bracket bolt tightening steps
Step 1
: 2 N·m (0.2 kg-m, 17 in-lb)
Step 2
: 9 - 11.8 N·m (0.92 - 1.2 kg-m, 79.9 - 104.2 in-lb)
AEM352
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