Page 1625 of 2267
IInstall new oil seal in the direction shown.
3. Apply engine oil to new oil seal and install it using a suitable
tool.
REAR OIL SEAL
1. Remove transaxle. (Refer to MT or AT section.)
2. Remove flywheel or drive plate.
3. Remove rear oil seal.
IBe careful not to scratch rear oil seal retainer.
IInstall new oil seal in the direction shown.
4. Apply engine oil to new oil seal and install it using a suitable
tool.
SEM715A Engine
outside
Dust seal lip Engine
inside
Oil seal lip
SEM998C
SEM999C
SEM715A Engine
inside
Oil seal lipEngine
outside
Dust seal lip
SEM001D Suitable tool
OIL SEAL REPLACEMENTSR20DE
EM-85
Page 1626 of 2267

ComponentsNLEM0130
1. Oil filler cap
2. Rocker cover
3. Rocker arm guide
4. Rocker arm
5. Shim
6. Hydraulic lash adjuster
7. Chain tensioner8. Camshaft sprocket
9. Camshaft
10. Camshaft bracket
11. Water outlet
12. Cylinder head
13. Valve14. Valve spring seat
15. Valve spring
16. Valve spring retainer
17. Valve collet
18. Spark plug
19. Cylinder head bolt
NEM355 Intake side
Refer to ªInstallationº in
ªCYLINDER HEADº.
Washer
Refer to
ªInstallationº in
ªCYLINDER HEADº.
Exhaust side
Refer to ªInstallationº
in ªCYLINDER HEADº.
137 - 157 (14 - 16, 101 - 116) Gasket
O-ring
Gasket
Rocker cover
gasket
Valve oil seal
6.3 - 8.3
(0.64 - 0.85, 55.6 - 73.8)
.SEC. 111×130
6.3 - 8.3
(0.64 - 0.85, 55.6 - 73.8)
9.0 - 11.8
(0.92 - 1.2,
79.9 - 104.2)
Refer to LC section (ªWater
Outletº, ªENGINE COOLING
SYSTEMº).
Refer to ªInstallationº in ªCYLINDER HEADº.
N´m (kg-m, in-lb)
N´m (kg-m, ft-lb)
Apply Genuine RTV Silicone SEALANT Part No. 999
MP-A7007 or equivalent.
Lubricate with new engine oil.
CYLINDER HEADSR20DE
Components
EM-86
Page 1627 of 2267
RemovalNLEM01311. Release fuel pressure.
Refer to EC-SR-31, ªFuel Pressure Releaseº.
2. Remove engine under covers.
3. Remove front RH wheel and engine side cover.
4. Drain coolant by removing cylinder block drain plug and radia-
tor drain cock. Refer to MA-29, ªChanging Engine Coolantº.
5. Remove radiator.
6. Remove air duct to intake manifold.
7. Disconnect the following parts:
IVacuum hoses
IFuel hoses
IWires
IHarness
IConnectors
IFront exhaust tube
8. Remove all spark plugs.
9. Remove rocker cover bolts in numerical order.
10. Remove rocker cover.
11. Remove intake manifold supports.
12. Remove water pipe assembly.
SEM029G Engine
front
Loosen in numerical order.Rocker cover
SEM030G Intake manifold
supports
SEM065GIntake
manifold
CYLINDER HEADSR20DE
Removal
EM-87
Page 1628 of 2267
13. Set No. 1 piston at TDC of its compression stroke.
IRotate crankshaft until mating mark on camshaft sprocket
is set at position indicated in figure.
14. Remove chain tensioner.
15. Remove distributor.
Do not turn rotor with distributor removed.
16. Remove camshaft sprockets.
IFor retiming in cylinder head removal, apply paint mark to
timing chain matched with mating marks of camshaft
sprockets.
SEM983C
SEM031G Mating mark
Mating mark
RH camshaft sprocketLH camshaft sprocket
.SEM032G Chain
tensioner
SEM033G Rotor head position
(No. 1 cylinder at TDC)
SEM034G
CYLINDER HEADSR20DE
Removal (Cont'd)
EM-88
Page 1629 of 2267

17. Remove camshaft brackets and camshafts.
IMark these parts' original positions for reassembly.
18. Remove starter motor.
19. Remove the following water hoses:
IWater hose for cylinder block.
IWater hoses for heater.
20. Remove cylinder head outside bolts.
21. Remove cylinder head bolts in numerical order.
IRemoving bolts in incorrect order could result in a warped
or cracked cylinder head.
ILoosen cylinder head bolts in two or three steps.
22. Remove cylinder head completely with intake and exhaust
manifolds.
Disassembly
CAUTION:
IWhen installing camshafts, chain tensioners, oil seals or
other sliding parts, lubricate contacting surfaces with new
engine oil.
IWhen tightening cylinder head bolts, camshaft sprocket
bolts, cramshaft pulley bolt and seat surfaces, lubricate
with new engine oil.
IIf a hydraulic lash adjuster is kept on its side, there is a
risk of air entering it. After removal, always set hydraulic
SEM035G Engine
frontRH camshaft
Camshaft bracket
LH camshaft
Loosen in numerical order.
SEM036G
SEM037G Water outletWater inlet
SEM978C
SEM878CA OK
NG
CYLINDER HEADSR20DE
Removal (Cont'd)
EM-89
Page 1630 of 2267
lash adjuster straight up, or keep it soaked in new engine
oil.
IDo not disassemble hydraulic lash adjusters.
IAttach tags to lash adjusters so as not to mix them up.
1. Remove rocker arms, shims, rocker arm guides and hydraulic
lash adjusters from cylinder head.
CAUTION:
Keep parts in order so that they can be installed in their origi-
nal positions during assembly.
2. Remove exhaust manifold cover.
3. Remove exhaust manifold.
4. Remove water outlet.
5. Remove intake manifold.
6. Remove thermostat housing with water pipe.
SEM202D Rocker arm guide
Rocker arm
Shim
Hydraulic
lash adjuster
SEM059G Loosen in numerical order.
.SEM082D Water
outlet
SEM061G Loosen in numerical order.
NEM215 Water pipe Thermostat
housing
CYLINDER HEADSR20DE
Disassembly (Cont'd)
EM-90
Page 1631 of 2267
7. Remove valve components with Tool.
8. Remove valve oil seal with a suitable tool.
Inspection
CYLINDER HEAD DISTORTION
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 or resurface.
Resurfacing limit:
The limit of cylinder head is determined by the cylinder block
resurfacing in an engine.
Amount of cylinder head resurfacing is ªAº.
Amount of cylinder block resurfacing is ªBº.
The maximum limit is as follows:
A + B = 0.2 mm (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:
136.9 - 137.1 mm (5.390 - 5.398 in)
CAMSHAFT VISUAL CHECK
Check camshaft for scratches, seizure and wear.
SEM604E Compressor assemblyAttachment
SEM994C
SEM925C
CYLINDER HEADSR20DE
Inspection
EM-91
Page 1632 of 2267

CAMSHAFT RUNOUT
1. Measure camshaft runout at the center journal.
Runout (Total indicator reading):
Standard
Less than 0.02 mm (0.0008 in)
Limit
0.1 mm (0.004 in)
2. If it exceeds the limit, replace camshaft.
CAMSHAFT CAM HEIGHT
1. Measure camshaft cam height.
Standard cam height:
Intake
37.775 mm (1.4872 in)
Exhaust
37.404 mm (1.4726 in)
Cam 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:
28.000 - 28.021 mm (1.1024 - 1.1032 in)
3. Measure outer diameter of camshaft journal.
Standard outer diameter:
27.950 - 27.970 mm (1.1004 - 1.1012 in)
4. If clearance exceeds the limit, replace camshaft and/or cylin-
der head.
Camshaft journal clearance:
Standard
0.030 - 0.071 mm (0.0012 - 0.0028 in)
Limit
0.15 mm (0.0059 in)
SEM926C
SEM549A
SEM927C
.SEM012A
CYLINDER HEADSR20DE
Inspection (Cont'd)
EM-92