NISSAN PICK-UP 1999 Repair Manual

b. Apply a continuous bead of liquid gasket to mating surface
of rear oil seal retainer.
lUse Genuine Liquid Gasket or equivalent.
lApply around inner side of bolt holes.
AEM404
OIL SEAL REPLACEMENTKA24DE
EM-2023

V1Oil filler cap
V2Rocker cover
V3Camshaft bracket
V4Intake camshaft
V5Exhaust camshaft
V6Shim
V7Valve lifter
V8Valve cotter
V9Spring retainer
V10Valve spring
V11Spring seat
V12Valve oil seal
V13Intake valve
V14Exhaust valve
V15Cylinder head
V16Cylinder head bolt
SEM996F
CYLINDER HEADKA24DE
EM-2024

CAUTION:
lWhen installing camshafts, chain tensioners, oil seals,
or other sliding parts, lubricate contacting surfaces with
new engine oil.
lApply new engine oil to threads and seat surfaces when
installing cylinder head, camshaft sprocket, crankshaft
pulley, and camshaft bracket.
lAttach tags to valve lifters so as not to mix them up.
lBefore removing camshaft and idler sprockets, apply
paint marks to them for retiming.
Removal
1. Drain coolant from radiator and cylinder block. Refer to MA
section (ªChanging Engine Coolantº, ªENGINE MAINTE-
NANCEº).
2. Remove upper timing chain and idler sprocket.
lRefer to ªUPPER TIMING CHAINº (EM-2015) and ªIDLER
SPROCKETº (EM-2016), ªRemovalº, ªTIMING CHAINº.
lFor retiming during cylinder head removal/installation,
apply paint marks to camshaft sprockets, upper timing
chain, lower timing chain and idler sprocket.
3. Remove camshaft brackets and camshafts.
lMark the original positions of these parts for reassem-
bly.
4. Remove cylinder head bolts in numerical order.
lRemoving bolts in incorrect order could result in a
warped or cracked cylinder head.
lLoosen cylinder head bolts in two or three steps.
5. Remove cylinder head and cylinder head gasket.
Installation
1. Tighten cylinder head bolts in numerical order using the fol-
lowing procedure:
a. Tighten all bolts to 29 Nzm (3.0 kg-m, 22 ft-lb).
b. Tighten all bolts to 79 Nzm (8.1 kg-m, 59 ft-lb).
SEM997F
SEM274D
SEM275D
CYLINDER HEADKA24DE
EM-2025

c. Loosen all bolts completely.
d. Tighten all bolts to 25 to 34 Nzm (2.5 to 3.5 kg-m, 18 to 25
ft-lb).
e. Turn all bolts 86 to 91É clockwise. If angle wrench is not
available, mark all cylinder head bolts on the side facing
engine front. Then, turn each cylinder head bolt 86 to 91É
clockwise.
2. Install camshafts and camshaft brackets in the order shown
using the following procedure:
a. Set camshafts and camshaft brackets.
b. Tighten all bolts to 2 Nzm (0.2 kg-m, 17 in-lb).
c. Tighten all bolts to 9.1 to 11.7 Nzm (0.92 to 1.2 kg-m, 80 to
104 in-lb).
lApply new engine oil to bolt threads and seat surfaces.
3. Install upper timing chain and idler sprocket.
lRefer to ªUPPER TIMING CHAINº (EM-2019) and ªIDLER
SPROCKETº (EM-2019), ªInstallationº, ªTIMING CHAINº.
4. Refill engine coolant. Refer to MA section (ªChanging Engine
Coolantº, ªENGINE MAINTENANCEº).
Disassembly
1. Remove intake manifold and exhaust manifold. Refer to
ªOUTER COMPONENT PARTSº (EM-2007).
2. Remove valve components.
3. Remove valve oil seal with a suitable tool.
Inspection
CYLINDER HEAD DISTORTION
Clean surface of cylinder head.
Use a reliable straightedge and feeler gauge to check the flat-
ness of cylinder head surface.
Check along six positions shown in the figure.
Head surface flatness:
Standard Less than 0.03 mm (0.0012 in)
Limit 0.1 mm (0.004 in)
If beyond the specified limit, replace it or resurface it.
Resurfacing limit:
SEM276D
SEM998F
SEM692D
SEM294D
CYLINDER HEADKA24DE
Installation (Cont'd)
EM-2026

The limit of cylinder head resurfacing is determined by the
cylinder block resurfacing.
Amount of cylinder head resurfacing is ªAº.
Amount of cylinder block resurfacing is ªBº.
The maximum limit:
A+B=0.2mm(0.008 in)
After resurfacing cylinder head, check that camshaft rotates
freely by hand. If resistance is felt, cylinder head must be
replaced.
Nominal cylinder head height:
126.3 - 126.5 mm (4.972 - 4.980 in)
CAMSHAFT VISUAL CHECK
Check camshaft for scratches, seizure and wear.
CAMSHAFT RUNOUT
1. Measure camshaft runout at the center journal.
Runout (Total indicator reading):
Standard
Less than 0.02 mm (0.0008 in)
Limit
0.04 mm (0.0016 in)
2. If it exceeds the limit, replace camshaft.
CAMSHAFT CAM HEIGHT
1. Measure camshaft cam height.
Standard cam height:
Intake 42.505 - 42.695 mm (1.673 - 1.681 in)
Exhaust 40.905 - 41.095 mm (1.610 - 1.618 in)
Cam height wear limit:
Intake & Exhaust
0.2 mm (0.008 in)
2. If wear is beyond the limit, replace camshaft.
CAMSHAFT JOURNAL CLEARANCE
1. Install camshaft bracket and tighten bolts to the specified
torque.
2. Measure inner diameter of camshaft bearing.
Standard inner diameter:
#1 to #5 journals
28.000 - 28.025 mm (1.1024 - 1.1033 in)
SEM926C
SEM549A
SEM295D
CYLINDER HEADKA24DE
Inspection (Cont'd)
EM-2027

3. Measure outer diameter of camshaft journal.
Standard outer diameter:
#1 to #5 journals
27.935 - 27.955 mm (1.0998 - 1.1006 in)
4. If clearance exceeds the limit, replace camshaft and/or cyl-
inder head.
Camshaft journal clearance:
Standard 0.045 - 0.090 mm (0.0018 - 0.0035 in)
Limit 0.12 mm (0.0047 in)
CAMSHAFT END PLAY
1. Install camshaft in cylinder head.
2. Measure camshaft end play.
Camshaft end play:
Standard
0.070 - 0.148 mm (0.0028 - 0.0058 in)
Limit
0.2 mm (0.008 in)
3. If end play exceeds the limit, replace camshaft and remea-
sure camshaft end play.
4. If end play still exceeds the limit after replacing camshaft,
replace cylinder head.
CAMSHAFT SPROCKET RUNOUT
1. Install sprocket on camshaft.
2. Measure camshaft sprocket runout.
Runout (Total indicator reading):
Limit 0.15 mm (0.0059 in)
3. If it exceeds the limit, replace camshaft sprocket.
VALVE GUIDE CLEARANCE
1. Measure valve deflection as shown in figure. (Valve and
valve guide mostly wear in this direction.)
Valve deflection limit (Dial gauge reading):
Intake & Exhaust
0.2 mm (0.008 in)
SEM012A
SEM296D
AEM328
SEM297D
CYLINDER HEADKA24DE
Inspection (Cont'd)
EM-2028

2. If it exceeds the limit, check valve to valve guide clearance.
a. Measure valve stem diameter and valve guide inner diam-
eter.
b. Check that clearance is within specification.
Valve to valve guide clearance = Valve guide inner diameter
þ Valve stem diameter:
Unit: mm (in)
Standard Limit
Intake0.020 - 0.053
(0.0008 - 0.0021)0.08 (0.0031)
Exhaust0.040 - 0.073
(0.0016 - 0.0029)0.1 (0.004)
c. If it exceeds the limit, replace valve and remeasure clear-
ance.
lIf clearance still exceeds the limit after replacing valve,
replace the valve guide.
VALVE GUIDE REPLACEMENT
1. To remove valve guide, heat cylinder head to 120 to 140ÉC
(248 to 284ÉF) by soaking in heated oil.
2. Drive out valve guide with a press [under a 20 kN (2 ton, 2.2
US ton, 2.0 Imp ton) pressure] or hammer and suitable tool.
3. Ream cylinder head valve guide hole.
Valve guide hole diameter
(for service parts):
Intake & Exhaust
11.175 - 11.196 mm (0.4400 - 0.4408 in)
SEM298D
SEM008A
SEM299D
SEM300D
CYLINDER HEADKA24DE
Inspection (Cont'd)
EM-2029

4. Heat cylinder head to 120 to 140ÉC (248 to 284ÉF) and press
service valve guide onto cylinder head.
Projection ªLº:
13.3 - 13.9 mm (0.524 - 0.547 in)
5. Ream valve guide.
Finished size:
Intake & Exhaust
7.000 - 7.018 mm (0.2756 - 0.2763 in)
VALVE SEATS
Check valve seats for pitting at contact surface. Resurface or
replace if excessively worn.
lBefore repairing valve seats, check valve and valve
guide for wear. If they have worn, replace them. Then
correct valve seat.
lUse both hands to cut uniformly.
REPLACING VALVE SEAT FOR SERVICE PARTS
1. Bore out old seat until it collapses. Boring should not con-
tinue beyond the bottom face of the seat recess in cylinder
head. Set the machine depth stop to ensure this.
2. Ream cylinder head recess.
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)
Use the valve guide center for reaming to ensure valve seat
will have the correct fit.
3. Heat cylinder head to 120 to 140ÉC (248 to 284ÉF).
4. Press fit valve seat until it seats on the bottom.
SEM301D
SEM300D
SEM302D
SEM795A
SEM008A
CYLINDER HEADKA24DE
Inspection (Cont'd)
EM-2030

5. Cut or grind valve seat using suitable tool to the specified
dimensions as shown in SDS.
6. After cutting, lap valve seat with abrasive compound.
7. Check valve seating condition.
Seat face angle ªaº:
45É15¢- 45É45¢deg.
Contacting width ªWº:
Intake
1.48 - 1.63 mm (0.0583 - 0.0642 in)
Exhaust
1.8 - 2.0 mm (0.071 - 0.079 in)
8. Use a depth gauge to measure the distance between the
mounting surface of the cylinder head spring seat and the
valve stem end. If the distance is shorter than specified,
repeat step 5 above to adjust it. If it is longer, replace the
valve seat with a new one.
Valve seat resurface limit ªLº:
Intake 42.02 - 42.52 mm (1.6543 - 1.6740 in)
Exhaust 42.03 - 42.53 mm (1.6547 - 1.6744 in)
VALVE DIMENSIONS
Check dimensions of each valve. For dimensions, refer to SDS
(EM-2049).
When valve head has been worn down to 0.5 mm (0.020 in) in
margin thickness, replace valve.
Grinding allowance for valve stem tip is 0.2 mm (0.008 in) or
less.
VALVE SPRING
Squareness
1. Measure dimension ªSº.
Out-of-square ªSº:
Less than 2.2 mm (0.087 in)
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
418.0 (42.6, 93.9) at 29.17 (1.1484)
Limit
393.0 (40.1, 88.4) at 29.17 (1.1484)
If it exceeds the limit, replace spring.
SEM892B
SEM621F
SEM188A
SEM288A
EM113
CYLINDER HEADKA24DE
Inspection (Cont'd)
EM-2031

VALVE LIFTER AND VALVE SHIM
1. Visually check contact and sliding surfaces for wear and
scratches.
2. Check diameter of valve lifter and valve lifter guide bore.
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)
If it exceeds the standard diameter or clearance, replace
valve lifter or cylinder head.
Assembly
1. Install valve component parts.
lAlways use new valve oil seal. Refer to ªOIL SEAL
REPLACEMENTº (EM-2021).
lBefore installing valve oil seal, install valve spring seat.
lInstall outer valve spring (uneven pitch type) with its
narrow pitch side toward cylinder head side.
lAfter installing valve component parts, tap valve stem tip
with plastic hammer to assure a proper fit.
Valve Clearance
CHECKING
Check valve clearance while engine is warm but not run-
ning.
1. Remove rocker cover and all spark plugs.
2. Set No. 1 cylinder at TDC on its compression stroke.
lAlign pointer with TDC mark on crankshaft pulley.
lCheck that valve lifters on No. 1 cylinder are loose and valve
lifters on No. 4 are tight.
If not, turn crankshaft one revolution (360É) and align as
above.
AEM410
AEM411
SEM303D
SEM638B
AEM355
CYLINDER HEADKA24DE
Inspection (Cont'd)
EM-2032