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3. Starting with the center bolt, torque bolts (1) to 24
Nꞏm ( 18 ft. lbs. ).
4. Install breather tube (3) to cylinder head cover (2).
5. Install breather drain tube (4) to cylinder head
cover (2).
INSTALLATION - CYL HEAD COVER GASKET
1. Clean oil from cylinder head cover gasket
2. Inspect cylinder head cover gasket for cuts or damage. Replace if damaged.
3. Place cylinder head cover gasket on top of rocker housing (2).
4. Install injector solenoid nuts (1) at injectors. Torque to 1.25 Nꞏm ( 11 in. lbs. ).
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5. Connect injector harness connectors (3) at cylinder head cover gasket.
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VALVES & SEATS - INTAKE/EXHAUST
DESCRIPTION
The valves (1,2) are made of heat resistant steel, and
have chrome plated stems to prevent scuffing. The
intake and exhaust valves are both similar in head
diameter and overall length, but they have unique face
angles which makes them non-interchangeable. The
valves are distinguished by unique dimples on the
exhaust valve head (2).
The exhaust valve springs are made from high
strength, chrome silicon steel. The exhaust valve
springs are also exhaust brake compatible.
STANDARD PROCEDURE
STANDARD PROCEDURE - VALVES, GUIDES AND SPRINGS
REMOVAL
1. Remove cylinder head (Refer to 9 - ENGINE/CYL-
INDER HEAD - REMOVAL).
2. Support cylinder head on stands, or install head
bolts upside down (through combustion surface
side) to protect injector tips from damage from
work bench.
3. Install the valve spring compressor mounting base
(1) as shown.
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4. Install the compressor top plate, washer, and nut.
Using a suitable wrench, tighten the nut (clockwise)
to compress the valve springs and remove the
locks.
5. Rotate the compressor nut counter-clockwise to
relieve tension on the springs. Remove the spring
compressor (1).
6. Remove the retainers (5), springs (4), valve seals
(3) (if necessary), and valves (2). Arrange or num-
ber all components so they can be installed in their
original locations.
7. Repeat the procedure on all cylinders to be
serviced.
CLEANING
Clean the valve stems with crocus cloth or a Scotch-Brite™ pad. Remove carbonwithasoftwirebrush.Clean
valves, springs, retainers, and valve retaining locks in a suitable solvent. Rinse in hot water and blow dry with com-
pressed air.
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INSPECTION
Visually inspect the valves for abnormal wear on the
heads, stems, and tips. Replace any valve that is
worn out or bent.
Measure the valve stem diameter in three places as
shown.
VALVE GUIDE BORE SPECIFICATIONS
VALVE GUIDE BORE SPECIFICATIONS
Valve guide bore diameter
Min. 7.027 mm (0.2767 in.)
Max. 7.077 mm (0.2786 in.)
Installed valve guide depth
Intake
Min. 0.584 mm ( 0.023 in.)
Max. 1.092 mm ( 0.043 in.)
Exhaust
Min. 0.965 mm ( 0.028 in.)
Max. 1.473 mm (0.058 in.)
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Measure the cylinder head valve guide bore.
Measure valve margin (rim thickness).
Measure the valve spring free length and maximum
inclination.
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Test valve spring force with tool C-647 (1). Specifica-
tion 72.0 — 80.7 lbs. when compressed to 35.33 mm
(1.39 in.).
INSTALLATION
1. Install new valve seals. The yellow seals are for the
intake valves and the green seals are for the
exhaust valves.
2. Install the valves in their original postion. The
exhaust valves are identified by a dimple on the
valve head.
3. Install the valve (2), springs (4), and retainer (5).
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4. Install the valve spring compressor tool 8319–A
(1)as shown.
5. Compress the valve springs and install the valve
retaining locks.
6. Remove the compressor and repeat the procedure
on the remaining cylinders.
7. Install new o-ring and sealing washer on injector.
8. Lubricate o-ring and injector bore.
9. Verify sealing washer (shim) was removed with old
injector.
10. Install injector Refer to (Refer to 14 - FUEL SYS-
TEM/FUEL INJECTION/FUEL INJECTOR -
INSTALLATION).
11. Install the cylinder head (Refer to 9 - ENGINE/
CYLINDER HEAD - INSTALLATION).
STANDARD PROCEDURE - VALVE LASH ADJUSTMENT AND VERIFICATION
NOTE: To obtain accurate readings, valve lash
measurements AND adjustments should only be
performed when the engine coolant temperature is
less than 60° C (140° F).
The 24–valve overhead system is a “low-maintenance”
design. Routine adjustments are no longer necessary,
however, measurement should still take place when
troubleshooting performance problems, or upon com-
pletion of a repair that includes removal and installa-
tion of the valve train components or injectors.
1. Disconnect battery negative cables.
2. Remove cylinder head cover (Refer to 9 - ENGINE/
CYLINDER HEAD/CYLINDER HEAD COVER(S) -
REMOVAL).
3. Using the crankshaft barring tool #7471–B, rotate crankshaft to align damper TDC mark to 12:00 o’clock position.
a. If both number one cylinder rocker levers are loose, continue to next step.
b. If both number one cylinder rocker levers are not loose, rotate crankshaft 360 degrees.