1998 NISSAN PICK-UP Repair Manual

VALVE SPRING
Squareness
1. Measure dimension ``S''.
Out-of-square ``S'': mm (in)
Outer
Intake Less than 2.5 (0.098)
Exhaust Less than 2.3 (0.091)
Inner
Intake Less than 2.3 (0.091)
Exhaust Less than 2.1 (0.083)
2. If it exceeds the limit, replace spring.
Pressure
Check valve spring pressure at specified spring height.
Pressure: N (kg, lb) at height mm (in)
Standard
Outer
Intake 604.1 (61.6, 135.8) at 37.6 (1.480)
Exhaust 640.4 (65.3, 144.0) at 34.1 (1.343)
Inner
Intake 284.4 (29.0, 63.9) at 32.6 (1.283)
Exhaust 328.5 (33.5, 73.9) at 29.1 (1.146)
Limit
Outer
Intake 567.8 (57.9, 127.7) at 37.6 (1.480)
Exhaust 620.8 (63.3, 139.6) at 34.1 (1.343)
Inner
Intake 266.8 (27.2, 60.0) at 32.6 (1.283)
Exhaust 318.7 (32.5, 71.7) at 29.1 (1.146)
If it exceeds the limit, replace spring.
ROCKER SHAFT AND ROCKER ARM
1. Check rocker shafts for scratches, seizure and wear.
2. Check outer diameter of rocker shaft.
Diameter:
21.979 - 22.000 mm (0.8653 - 0.8661 in)
3. Check inner diameter of rocker arm.
Diameter:
22.012 - 22.029 mm (0.8666 - 0.8673 in)
Rocker arm to shaft clearance:
0.012 - 0.050 mm (0.0005 - 0.0020 in)
lKeep rocker arm with hydraulic valve lifter standing to
prevent air from entering hydraulic valve lifter when
checking.
SEM288A
EM113
SEM233C
SEM234C
CYLINDER HEADKA
Inspection (Cont'd)
EM-32

Assembly
1. Install valve component parts.
lAlways use new valve oil seal. Refer to OIL SEAL
REPLACEMENT.
lBefore installing valve oil seal, install inner valve spring
seat.
lInstall outer valve spring (uneven pitch type) with its
narrow pitch side toward cylinder head side.
lAfter installing valve component parts, use plastic ham-
mer to lightly tap valve stem tip to assure a proper fit.
2. Install camshaft, placing knock pin towards front of engine
and in the top position.
lApply engine oil to camshaft when mounting onto cylin-
der head.
3. Install camshaft brackets.
lFront mark is punched on the camshaft bracket.
Location (from front side)Identification
Mark Punched
No. 1 51 Ð
No. 2 52 2
No. 3 53 Ð
No. 4 52 4
No. 5 55 Ð
4. Install rocker shaft with rocker arms.
lInstall retainer with cutout facing direction shown in figure at
left.
SEM638B
SEM236C
SEM606F
SEM399E
SEM274C
CYLINDER HEADKA
EM-33

5. Tighten bolts as shown in figure at left.
Installation
1. Set No. 1 piston at TDC on its compression stroke as follows:
a. Align mark on crankshaft pulley with ``0É'' position and con-
firm that distributor rotor head is set as shown in figure.
b. Confirm that knock pin on camshaft is set at the top.
2. Install cylinder head with new gasket and tighten cylinder
head bolts in numerical order.
lDo not rotate crankshaft and camshaft separately, or
valves will hit piston heads.
lTightening procedure
a. Tighten all bolts to 29 N´m (3.0 kg-m, 22 ft-lb).
b. Tighten all bolts to 78 N´m (8.0 kg-m, 58 ft-lb).
c. Loosen all bolts completely.
d. Tighten all bolts to 25 to 34 N´m (2.5 to 3.5 kg-m, 18 to
25 ft-lb).
e. Turn all bolts 80
+5
þ0degrees clockwise with an angle
wrench. If an angle wrench is not available, tighten all
bolts to 74 to 83 N´m (7.5 to 8.5 kg-m, 54 to 61 ft-lb).
SEM599F
SEM216C
SEM572F
SEM442C
SEM594F
CYLINDER HEADKA
Assembly (Cont'd)
EM-34

3. Set chain on camshaft sprocket by aligning each mating
mark. Then install camshaft sprocket to camshaft.
4. Tighten camshaft sprocket bolt.
5. Install rubber plugs. Refer to TIMING CHAIN, EM-21.
6. Check hydraulic valve lifter.
a. Push hydraulic valve lifter forcefully with your finger.
lBe sure to check it with rocker arm in its free position.
b. If valve lifter moves more than 1 mm (0.04 in), air may be
inside of it.
c. Bleed air off by running engine at 1,000 rpm under no-load
for about 20 minutes.
d. If hydraulic valve lifters are still noisy, replace them and bleed
air off again in the same manner as in step c.
7. Install rocker cover. Refer to TIMING CHAIN, EM-21.
lBe sure to avoid interference between rocker cover and
rocker arm.
8. Install intake and exhaust manifolds. Refer to ``OUTER COM-
PONENT PARTS'', EM-9.
SEM612F
SEM592F
SEM275C
CYLINDER HEADKA
Installation (Cont'd)
EM-35

WARNING:
lPosition vehicle on a flat and solid surface.
lPlace chocks at front and back of rear wheels.
lDo not remove engine until exhaust system has com-
pletely cooled off.
Otherwise, you may burn yourself and/or fire may break
out in fuel line.
lBefore disconnecting fuel hose, release fuel pressure.
Refer to EC section (``Fuel Pressure Release'').
lBe sure to hoist engine and transmission in a safe man-
ner.
lFor engines not equipped with engine slingers, attach
proper slingers and bolts described in PARTS CATA-
LOG.
CAUTION:
lWhen lifting engine, be sure to clear surrounding parts.
Take special care near accelerator wire casing, brake
lines and brake master cylinder.
lIn lifting the engine, always use engine slingers in a safe
manner.
lFor 4WD models, apply sealant between engine and
transmission. Refer to MT section (``Removal and Instal-
lation'').
SEM601FA
ENGINE REMOVALKA
EM-36

Removal
1. Drain coolant from engine block and radiator. Refer to MA
section (``Changing Engine Coolant'', ``ENGINE MAINTE-
NANCE'').
2. Release fuel pressure. Refer to EC section (``Fuel Pressure
Release'').
3. Remove negative battery cable.
4. Remove hood. Refer to BT section.
5. Remove power steering drive belt, alternator drive belt and
A/C compressor drive belt.
6. Remove radiator. Refer to LC section (``Radiator'', ``ENGINE
COOLING SYSTEM'').
7. Remove exhaust manifold heat shield.
8. Disconnect exhaust system from exhaust manifold.
9. Discharge refrigerant. Refer to HA section (``R-134a Service
Procedure'', ``SERVICE PROCEDURES'').
10. Disconnect refrigerant lines. Refer to HA section (``Refriger-
ant Lines'', ``SERVICE PROCEDURES'').
11. Disconnect accelerator wire, vacuum hoses, electrical
connectors, heater hoses and vacuum booster hose.
12. Remove four power steering pump bolts.
13. Remove transmission. Refer to MT section (``Removal'',
``REMOVAL AND INSTALLATION'').
14. Remove LH and RH engine mounts.
15. Remove engine.
Installation
lInstall in reverse order of removal.
SEM602F
SEM603F
SEM604F
ENGINE REMOVALKA
EM-37

SEM812F
CYLINDER BLOCKKA
EM-38

CAUTION:
lWhen installing sliding parts (bearings, pistons, etc.),
lubricate contacting surfaces with new engine oil.
lPlace removed parts such as bearings and bearing caps
in their proper order and direction.
lWhen installing connecting rod nuts and main bearing
cap bolts, apply new engine oil to threads and seating
surfaces.
lDo not allow any magnetic materials to contact the ring
gear teeth of flywheel or drive plate.
Disassembly
PISTON AND CRANKSHAFT
1. Remove intake manifold.
2. Place engine on a work stand.
3. Drain coolant and oil.
4. Remove oil pan.
5. Remove water pump.
6. Remove timing chain.
7. Remove cylinder head.
8. Remove pistons with connecting rod.
9. Remove bearing caps and crankshaft.
lBefore removing bearing caps, measure crankshaft end
play. Refer to EM-47.
lBolts should be loosened in two or three steps.
Inspection
PISTON AND PISTON PIN CLEARANCE
1. Measure inner diameter of piston pin hole ``dp''.
Standard diameter ``dp'':
21.002 - 21.008 mm (0.8268 - 0.8271 in)
2. Measure outer diameter of piston pin ``Dp''.
Standard diameter ``Dp'':
20.993 - 20.998 mm (0.8265 - 0.8267 in)
3. Calculate piston pin clearance.
dp þ Dp = 0.008 - 0.012 mm (0.0003 - 0.0005 in)
If it exceeds the above value, replace piston assembly with
pin.
SEM744-A
EEM118
AEM023
AEM024
CYLINDER BLOCKKA
EM-39