6. Hold the camshaft with Special Tool 8428 Camshaft
Wrench , while removing the camshaft sprocket
bolt and sprocket.
7. Using Special Tool 8428 Camshaft Wrench, gently
allow the camshaft to rotate 5° clockwise until the
camshaft is in the neutral position (no valve load).
8. Starting at the outside working inward, loosen the
camshaft bearing cap retaining bolts 1/2 turn at a
time. Repeat until all load is off the bearing caps.
CAUTION: DO NOT STAMP OR STRIKE THE CAM-
SHAFT BEARING CAPS. SEVERE DAMAGE WILL
OCCUR TO THE BEARING CAPS.
NOTE: When the camshaft is removed the rocker
arms may slide downward, mark the rocker arms
before removing camshaft.
9. Remove the camshaft bearing caps and the
camshaft.
INSTALLATION
1. Lubricate camshaft journals with clean engine oil.
NOTE: Position the left side camshaft so that the
camshaft sprocket dowel is near the 1 o’clock
position, This will place the camshaft at the neu-
tral position easing the installation of the camshaft
bearing caps.
2. Position the camshaft into the cylinder head.
3. Install the camshaft bearing caps, hand tighten the
retaining bolts.
NOTE: Caps should be installed so that the
stamped numbers on the caps are in numerical
order, ( 1 thru 4 ) from the front to the rear of the
engine. All caps should be installed so that the
stamped arrows on the caps point toward the front
of the engine.
4. Working in 1/2 turn increments, tighten the bearing
cap retaining bolts starting with the middle cap
working outward.
5. Torque the camshaft bearing cap retaining bolts to
11 N ꞏm ( 1 0 0 i n . l b s . ) .
6. Position the camshaft drive gear into the timing chain aligning the V6 mark between the two marked chain links
(Two links marked during removal).
7. Using Special Tool 8428 Camshaft Wrench, rotate the camshaft until the camshaft sprocket dowel is aligned with
the slot in the camshaft sprocket. Install the sprocket onto the camshaft.
CAUTION: Remove excess oil from camshaft sprocket bolt. Failure to do so can cause bolt over-torque
resulting in bolt failure.
8. Remove excess oil from bolt, then install the camshaft sprocket retaining bolt and hand tighten.
9. Remove Special Tool 8379 timing chain wedge.
VALVES & SEATS - INTAKE/EXHAUST
DESCRIPTION
The valves are made of heat resistant steel and have chrome plated stems to prevent scuffing. Each valve is actu-
ated by a roller rocker arm which pivots on a stationary lash adjuster. All valves use three bead lock keepers to
retain the springs and promote valve rotation.
STANDARD PROCEDURE - REFACING
NOTE: Valve seats that are worn or burned can be
reworked, provided that correct angle and seat
width are maintained. Otherwise the cylinder head
must be replaced.
NOTE: When refacing valves (4) and valve seats, it
is important that the correct size valve guide pilot
be used for reseating stones. A true and complete
surface must be obtained.
1. Using a suitable dial indicator measure the center
of the valve seat. Total run out must not exceed
0.051 mm (0.002 in).
2. Apply a small amount of Prussian blue to the valve
seat, insert the valve into the cylinder head, while
applying light pressure on the valve rotate the
valve. Remove the valve and examine the valve
face. If the blue is transferred below the top edge
of the valve face, lower the valve seat using a 15
degree stone. If the blue is transferred to the bot-
tom edge of the valve face, raise the valve seat
using a 65 degree stone.
3. When the seat is properly positioned the width of the intake seat must be 1.75 - 2.36 mm (0.0689 - 0.0928 in.)
and the exhaust seat must be 1.71 - 2.32 mm (0.0673 - 0.0911 in.).
4. Check the valve spring (6) installed height after refacing the valve andseat. The installed height for both intake
and exhaust valve springs must not exceed 40.74 mm (1.6039 in.).
5. The valve seat and valve face must maintain a face angle of 44.5 - 45 ° angle.
REMOVAL
NOTE: The cylinder heads must be removed in
order to perform this procedure.
1. Remove rocker arms and lash adjusters (Refer to 9
- ENGINE/CYLINDER HEAD/ROCKER ARM /
ADJUSTER ASSY - REMOVAL).
2. Remove the camshaft bearing caps and the cam-
shaft.
NOTE: All valve springs and valves are removed in
the same manner; this procedure only covers one
valve and valve spring.
3. Using Special Tool C-3422–B or C-3422–C Valve
Spring Compressor and Special tool 8519 Adapter,
compress the valve spring.
NOTE: It may be necessary to tap the top of the
valve spring to loosen the spring retainers locks
enough to be removed.
4. Remove the two spring retainer lock halves.
NOTE: the valve spring is under tension use care when releasing the valve spring compressor.
5. Remove the valve spring compressor.
6. Remove the spring retainer, and the spring.
NOTE: Check for sharp edges on the keeper grooves. Remove any burrs from thevalvestembeforeremov-
ing the valve from the cylinder head.
7. Remove the valve from the cylinder head.
NOTE: The valve stem seals are common between intake and exhaust.
8. Remove the valve stem seal. Mark the valve for proper installation.
TESTING VALVE SPRINGS
NOTE: Whenever the valves are removed from the
cylinder head it is recommended that the valve
springs be inspected and tested for reuse.
Inspect the valve springs for physical signs of wear or
damage. Turn table of tool C-647 (1) until surface is in
line with the 40.12 mm (1.579 in.) mark on the
threaded stud and the zero mark on the front. Place
spring over the stud on the table and lift compressing
lever to set tone device. Pull on torque wrench until a
Ping is heard. Take reading on torque wrench at this
instant. Multiply this reading by two. This will give the
spring load at test length. Fractional measurements
are indicated on the table for finer adjustments. Refer
to Specifications Section to obtain specified height and
allowable tensions. Replace any springs that do not
meet specifications.
INSTALLATION
1. coat the valve stem with clean engine oil and insert
it into the cylinder head.
2. Install the valve stem seal. make sure the seal is
fully seated and that the garter spring at the top of
the seal is intact.
3. Install the spring and the spring retainer.
4. Using the valve spring compressor, compress the
spring and install the two valve spring retainer
halves.
5. Release the valve spring compressor and make
sure the two spring retainer halves and the spring
retainer are fully seated.
6. lubricate the camshaft journal with clean engine oil
then Position the camshaft (with the sprocket dowel
on the left camshaft at 11 o’clock and the right
camshaft at 12 o’clock), then position the camshaft
bearing caps.
7. Install the camshaft bearing cap retaining bolts.
Tighten the bolts 9-13 Nꞏm (100 in. lbs.) in 1/2 turn
increments in the sequence shown .
8. Position the hydraulic lash adjusters and rocker
arms (Refer to 9 - ENGINE/CYLINDER HEAD/
ROCKER ARM / ADJUSTER ASSY -
INSTALLATION).
SPRINGS-VALVE
DESCRIPTION
The valve springs are made from high strength chrome silicon steel. The springs are NOT common for intake and
exhaust applications. The exhaust spring has an external damper. The valve spring seat is integral with the valve
stem seal, which is a positive type seal to control lubrication.
REMOVAL
1. Remove the cylinder head cover (Refer to 9 - ENGINE/CYLINDER HEAD/CYLINDER HEAD COVER(S) -
REMOVAL).
2. Using Special Tool 8516 Valve Spring Compressor, remove the rocker armsand the hydraulic lash adjusters.
3. Remove the spark plug for the cylinder the valve spring and seal are to be removed from.
4. Apply shop air to the cylinder to hold the valves in place when the spring is removed.
NOTE: All six valve springs and seals are removed in the same manner; this procedure only covers one
valve seal and valve spring.
5. Using Special Tool 8387 Valve Spring Compressor, compress the valve spring.
NOTE: It may be necessary to tap the top of the valve spring to loosen the spring retainers locks enough to
be removed.
6. Remove the two spring retainer lock halves.
NOTE: the valve spring is under tension use care when releasing the valve spring compressor.
7. Remove the valve spring compressor.
NOTE: The valve springs are NOT common between intake and exhaust.
8. Remove the spring retainer, and the spring.
9. Remove the valve stem seal.
NOTE: The valve stem seals are common between intake and exhaust.
INSTALLATION
NOTE: All six valve springs and seals are removed in the same manner; this procedure only covers one
valve seal and valve spring.
1. Apply shop air to the cylinder to holdthevalvesinplacewhilethespringis installed.
NOTE: The valve stem seals are common between intake and exhaust.
2. Install the valve stem seal.
NOTE: The valve springs are NOT common between intake and exhaust.
3. Install the spring retainer, and the spring.
4. Using Special Tool 8387 Valve Spring Compressor, compress the valve spring.
5. Install the two spring retainer lock halves.
NOTE: the valve spring is under tension use care when releasing the valve spring compressor.
6. Remove the valve spring compressor.
7. Disconnect the shop air to the cylinder.
8. Install the spark plug for the cylinder the valve spring and seal was installed on.
12. Verify the V6 mark on the camshaft sprocket is at the 12 o’clock position. Rotate the crankshaft one turn if
necessary.
13. Remove the crankshaft damper (Refer to 9 - ENGINE/ENGINE BLOCK/VIBRATION DAMPER - REMOVAL).
14. Remove the timing chain cover (Refer to 9 - ENGINE/VALVE TIMING/TIMINGBELT / CHAIN COVER(S) -
REMOVAL).
15. Lock the secondary timing chains to the idler
sprocket using Special Tool 8429 Timing Chain
Holding Fixture (1).
NOTE: Mark the secondary timing chain prior to
removal to aid in installation.
16. Mark the secondary timing chain, one link on
each side of the V6 mark on the camshaft drive
gear.
17. Remove the right side secondary chain tensioner
(Refer to 9 - ENGINE/VALVE TIMING/TIMING
BELT/CHAIN AND SPROCKETS - REMOVAL).
18. Remove the cylinder head access plug (1,2).
19. Remove the right side secondary chain guide
(Refer to 9 - ENGINE/VALVE TIMING/TIMING
BELT/CHAIN AND SPROCKETS - REMOVAL).
CAUTION: The nut on the right side camshaft
sprocket should not be removed for any reason,
as the sprocket and camshaft sensor target wheel
is serviced as an assembly. If the nut was
removed, torque nut to 5 Nꞏm (44 in. lbs.).
20. Remove the retaining bolt and the camshaft drive
gear.
CAUTION: Do not allow the engine to rotate.
severe damage to the valve train can occur.
CAUTION: Do not overlook the four smaller bolts at the front of the cylinderhead.Donotattempttoremove
the cylinder head without removing these four bolts.
CAUTION: Do not hold or pry on the camshaft target wheel for any reason. A damaged target wheel can
result in a vehicle no start condition.
NOTE: The cylinder head is attached to the cylin-
der block with twelve bolts.
21. Remove the cylinder head retaining bolts.
22. Remove the cylinder head and gasket. Discard
the gasket.
CAUTION: Do not lay the cylinder head on its gas-
ket sealing surface, do to the design of the cylin-
der head gasket any distortion to the cylinder
head sealing surface may prevent the gasket from
properly sealing resulting in leaks.
INSTALLATION
INSTALLATION RIGHT CYLINDER HEAD
NOTE: The cylinder head bolts are tightened using
a torque plus angle procedure. The bolts must be
examined BEFORE reuse. If the threads are
necked down (2) the bolts should be replaced.
Necking can be checked by holding a straight edge
against the threads. If all the threads do not contact
the scale, the bolt should be replaced.
CAUTION: When cleaning cylinder head and cylin-
der block surfaces, DO NOT use a metal scraper
because the surfaces could be cut or ground. Use
only a wooden or plastic scraper (1).
1. Clean the cylinder head and cylinder block mating
surfaces.