Downloaded from www.Manualslib.com manuals search engine VALVE SPRING
DESCRIPTION
The valve springs are made from high strength
chrome silicon steel. The springs are common for
intake and exhaust applications. The valve spring
seat is integral with the valve stem seal, which is a
positive type seal to control lubrication.
HYDRAULIC LASH ADJUSTER
DESCRIPTION
Valve lash is controlled by hydraulic lash adjusters
that are stationary mounted in the cylinder heads.
The lash adjusters have a hole in the ball plunger
that feeds oil through the rocker arm squirt holes for
rocker arm roller and camshaft lobe lubrication.
TIMING DRIVE SYSTEM
DESCRIPTION
The timing drive system has been designed to pro-
vide quiet performance and reliability to support a
non-free wheelingengine. Specifically the intake
valves are non-free wheeling and can be easily dam-
aged with forceful engine rotation if camshaft-to-
crankshaft timing is incorrect. The timing drive
system consists of a primary chain and two second-
ary timing chain drives.
OPERATION
The primary timing chain is a single inverted tooth
type. The primary chain drives the large fifty tooth
idler sprocket directly from a 25 tooth crankshaft
sprocket. Primary chain motion is controlled by a
pivoting leaf spring tensioner arm and a fixed guide.
The arm and the guide both use nylon plastic wear
faces for low friction and long wear. The primary
chain receives oil splash lubrication from the second-
ary chain drive and oil pump leakage. The idler
sprocket assembly connects the primary and second-
ary chain drives. The idler sprocket assembly con-
sists of two integral thirty tooth sprockets and a fifty
tooth sprocket that is splined to the assembly. The
spline joint is a non ± serviceable press fit anti rattle
type. A spiral ring is installed on the outboard side of
the fifty tooth sprocket to prevent spline disengage-
ment. The idler sprocket assembly spins on a station-
ary idler shaft. The idler shaft is press-fit into the
cylinder block. A large washer on the idler shaft bolt
and the rear flange of the idler shaft are used to con-
trol sprocket thrust movement. Pressurized oil is
routed through the center of the idler shaft to pro-
vide lubrication for the two bushings used in the
idler sprocket assembly.There are two secondary drive chains, both are
inverted tooth type, one to drive the camshaft in each
SOHC cylinder head. There are no shaft speed
changes in the secondary chain drive system. Each
secondary chain drives a thirty tooth cam sprocket
directly from the thirty tooth sprocket on the idler
sprocket assembly. A fixed chain guide and a hydrau-
lic oil damped tensioner are used to maintain tension
in each secondary chain system. The hydraulic ten-
sioners for the secondary chain systems are fed pres-
surized oil from oil reservoir pockets in the block.
Each tensioner also has a mechanical ratchet system
that limits chain slack if the tensioner piston bleeds
down after engine shut down. The tensioner arms
and guides also utilize nylon wear faces for low fric-
tion and long wear. The secondary timing chains
receive lubrication from a small orifice in the ten-
sioners. This orifice is protected from clogging by a
fine mesh screen which is located on the back of the
hydraulic tensioners.
CAMSHAFT
DESCRIPTION
The camshafts consist of powdered metal steel
lobes which are sinter-bonded to a steel tube. A steel
post or nose piece is friction-welded to the steel cam-
shaft tube. Five bearing journals are machined into
the camshaft, four on the steel tube and one on the
steel nose piece. Camshaft end play is controlled by
two thrust walls that border the nose piece journal.
Engine oil enters the hollow camshafts at the third
journal and lubricates every intake lobe rocker
through a drilled passage in the intake lobe.
ROCKER ARM
DESCRIPTION
The rocker arms are steel stampings with an inte-
gral roller bearing. The rocker arms incorporate a 2.8
mm (0.11 inch) oil hole in the lash adjuster socket for
roller and camshaft lubrication.
CYLINDER HEAD COVER
DESCRIPTION
The cylinder head covers are made of die cast mag-
nesium, and are not interchangeable from side-to-
side. It is imperative that nothing rest on the
cylinder head covers. Prolonged contact with other
items may wear a hole in the cylinder head cover.
9 - 6 4.7L ENGINEDN
DESCRIPTION AND OPERATION (Continued)
Downloaded from www.Manualslib.com manuals search engine (6) Identify the fluid in the cylinders (i.e. coolant,
fuel, oil, etc.).
(7) Make sure all fluid has been removed from the
cylinders.
(8) Repair engine or components as necessary to
prevent this problem from occurring again.
(9) Squirt engine oil into the cylinders to lubricate
the walls. This will prevent damage on restart.
(10) Install new spark plugs.
(11) Drain engine oil. Remove and discard the oil
filter.
(12) Install the drain plug. Tighten the plug to 34
N´m (25 ft. lbs.) torque.
(13) Install a new oil filter.
(14) Fill engine crankcase with the specified
amount and grade of oil.
(15) Connect the negative cable to the battery.
(16) Start the engine and check for any leaks.
VALVE SERVICE
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 and valve seats, it is
important that the correct size valve guide pilot be
used for reseating stones. A true and complete sur-
face 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 bottom 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 installed height after
refacing the valve and seat. The installed height for
both intake and exhaust valve springs must not
exceed 41.44 mm (1.6315 in.).
(5) The valve seat and valve face must maintain a
face angle of 44.5 ± 45 degrees angle.
ENGINE TIMINGÐVERIFICATION
CAUTION: The 4.7L is a non free-wheeling design
engine. Therefore, correct engine timing is critical.
NOTE: Components referred to as left hand or right
hand are as viewed from the drivers position inside
the vehicle.
NOTE: The blue link plates on the chains and the
dots on the camshaft drive sprockets may not line
up during the timing verification procedure. The
blue link plates are lined up with the sprocket dots
only when re-timing the complete timing drive.
Once the timing drive is rotated blue link-to-dot
alignment is no longer valid.
Engine base timing can be verified by the following
procedure:
(1) Remove the cylinder head covers. Refer to the
procedure in this section.
(2) Using a mirror, locate the TDC arrow on the
front cover (Fig. 11). Rotate the crankshaft until the
mark on the crankshaft damper is aligned with the
TDC arrow on the front cover. The engine is now at
TDC.
Fig. 10 Valve Assembly Configuration
1 ± VALVE LOCKS (3±BEAD)
2 ± RETAINER
3 ± VALVE STEM OIL SEAL
4 ± INTAKE VALVE
5 ± EXHAUST VALVE
6 ± VALVE SPRING
DN4.7L ENGINE 9 - 19
SERVICE PROCEDURES (Continued)
Downloaded from www.Manualslib.com manuals search engine (14) Install the crankshaft damper. Tighten
damper bolt 175 N´m (130 Ft. Lbs.).
(15) Install the power steering pump.
(16) Install the fan blade assembly and fan
shroud.
(17) Install the cylinder head cover.
(18) Install the intake manifold.
(19) Refill the cooling system
(20) Raise the vehicle.
(21) Install the exhaust pipe onto the left exhaust
manifold.
(22) Lower the vehicle.
(23) Connect the negative cable to the battery.
(24) Start the engine and check for leaks.
CYLINDER HEADÐRIGHT
REMOVAL
(1) Disconnect battery negitive cable.
(2) Raise the vehicle on a hoist.
(3) Disconnect the exhaust pipe at the right side
exhaust manifold.
(4) Drain the engine coolant. Refer to COOLING
SYSTEM.
(5) Lower the vehicle.
(6) Remove the intake manifold. Refer to proce-
dure in this section.
(7) Remove the cylinder head cover. Refer to proce-
dure in this section.
(8) Remove the fan shroud. Refer to COOLING
SYSTEM.
(9) Remove oil fill housing from cylinder head.
(10) Remove accessory drive belt. Refer to COOL-
ING SYSTEM.
(11) Rotate the crankshaft until the damper timing
mark is aligned with TDC indicator mark (Fig. 57).
(12) Verify the V8 mark on the camshaft sprocket
is at the 12 o'clock position (Fig. 59). Rotate the
crankshaft one turn if necessary.
(13) Remove the crankshaft damper. Refer to
Crankshaft Damper in this section.(14) Remove the timing chain cover. Refer to Tim-
ing Chain Cover in this section.
(15) Lock the secondary timing chains to the idler
sprocket using Special Tool 8515 (Fig. 58).
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 V8 mark on the camshaft drive gear
(Fig. 59).
(17) Remove the right side secondary chain ten-
sioner. Refer to Timing Chain and Sprockets in this
section.
(18) Remove the cylinder head access plug (Fig.
64).
(19) Remove the right side secondary chain guide.
Refer to Timing Chain and Sprockets in this section.
(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 cylinder head. Do not attempt to
remove the cylinder head without removing these
four bolts.
CAUTION: Do not hold or pry on the camshaft tar-
get wheel for any reason. A damaged target wheel
can result in a vehicle no start condition.
Fig. 63 Cylinder Head Tightening Sequence
Fig. 64 Cylinder Head Access Plugs
1 ± RIGHT CYLINDER HEAD ACCESS PLUG
2 ± LEFT CYLINDER HEAD ACCESS PLUG
9 - 44 4.7L ENGINEDN
REMOVAL AND INSTALLATION (Continued)
Downloaded from www.Manualslib.com manuals search engine INSTALLATION
(1) Lubricate camshaft journals with clean engine
oil.
NOTE: Position the right side camshaft so that the
camshaft sprocket dowel is near the 10 o'clock
position, This will place the camshaft at the neutral
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.
(4) Working in 1/2 turn increments, tighten the
bearing cap retaining bolts starting with the middle
cap working outward (Fig. 100).
(5) Torque the camshaft bearing cap retaining
bolts to 11 N´m (100 in. lbs.).
(6) Position the camshaft drive gear into the tim-
ing chain aligning the V8 mark between the two
marked chain links (Two links marked during
removal) (Fig. 101).
(7) Using the adjustable pliers, rotate the cam-
shaft until the camshaft sprocket dowel is aligned
with the slot in the camshaft sprocket. Install the
sprocket onto the camshaft (Fig. 102).
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 camshaft sprocket bolt,
then install the camshaft sprocket retaining bolt and
hand tighten.
(9) Remove timing chain wedge special tool 8350
(Fig. 97).
(10) Using Special Tool 6958 spanner wrench with
adapter pins 8346 (Fig. 103), torque the camshaft
sprocket retaining bolt to 122 N´m (90 ft. lbs.).
(11) Install the camshaft position sensor (Fig. 98).
(12) Install the cylinder head cover.
CRANKSHAFT MAIN BEARINGS
CRANKSHAFT MAIN BEARING SELECTION
The main bearings are ªselect fitº to achieve proper
oil clearances. For main bearing selection, the crank-
shaft position sensor target wheel has grade identifi-
cation marks stamped into it (Fig. 104). These marks
are read from left to right, corresponding with jour-
nal number 1, 2, 3, 4 and 5. The crankshaft position
sensor target wheel is mounted to the number 8
counter weight on the crankshaft.
NOTE: Service main bearings color coded. These
color codes identify what size (grade) the bearing
is.
CHECKING CRANKSHAFT END PLAY
(1) Mount a dial indicator to a stationary point at
front of engine. Locate the probe perpendicular
against nose of crankshaft (Fig. 105).
(2) Move the crankshaft all the way to the rear of
it's travel.
(3) Zero the dial indicator.
(4) Move the crankshaft all the way to the front of
it's travel and read the dial indicator. Refer to Crank-
shaft End Play Specification Chart.
OIL PAN 4X2 VEHICLE
REMOVAL
(1) Drain the cooling system. Refer to COOLING
SYSTEM.
(2) Remove the upper fan shroud. Refer to proce-
dure in this section.
(3) Remove the throttle body resonator and air
inlet hose.
(4) Remove the intake manifold. Refer to proce-
dure in this section.
(5) Raise vehicle on hoist.
(6) Disconnect exhaust pipe at exhaust manifolds.
Refer to EXHAUST SYSTEM.
(7) Remove the structural dust cover (Fig. 106).
Refer to procedure in this section.
(8) Drain engine oil and remove oil filter.
(9) Position suitable jack under engine.
Fig. 100 Camshaft Bearing Caps Tightening
Sequence
DN4.7L ENGINE 9 - 61
REMOVAL AND INSTALLATION (Continued)
Downloaded from www.Manualslib.com manuals search engine TORQUE SPECIFICATIONS
TORQUE CHART 5.2L ENGINE
DESCRIPTION N´m Ft. In.
Lbs. Lbs.
Camshaft SprocketÐBolt 68 50 Ð
Camshaft Thrust PlateÐBolts 24 Ð 210
Chain Case CoverÐBolts 41 30 Ð
Connecting Rod CapÐBolts 61 45 Ð
Main Bearing CapÐBolts 115 85 Ð
Crankshaft PulleyÐBolts 24 Ð 210
Cylinder HeadÐBolts
Step 1 68 50 Ð
Step 2 143 105 Ð
Cylinder Head CoverÐBolts 11 Ð 95
Engine Support Bracket to
BlockÐ41 30 Ð
Bolts (4WD)
Exhaust Manifold to Cylinder
HeadÐ34 25 Ð
Bolts/Nuts
FlywheelÐBolts 75 55 Ð
Front InsulatorÐThrough
bolt/nut95 70 Ð
Front Insulator to Support
BracketÐ
Stud Nut (4WD) 41 30 Ð
Through Bolt/Nut 102 75 Ð
Front Insulator to BlockÐ 95 70 Ð
Bolts (2WD)
GeneratorÐMounting Bolts 41 30 Ð
Intake ManifoldÐBolts Refer to Procedure
Oil PanÐBolts 24 Ð 215
Oil PanÐDrain Plug 34 25 Ð
Oil PumpÐMounting Bolts 41 30 Ð
Oil Pump CoverÐBolts 11 Ð 95
Rear Insulator to BracketÐ
Through68 50 Ð
Bolt (2WD)
Rear Insulator to
Crossmember41 30 Ð
Support BracketÐNut (2WD)
Rear Insulator to
CrossmemberÐ68 50 Ð
Nuts (4WD)
DESCRIPTION N´m Ft. In.
Lbs. Lbs.
Rear Insulator to
TransmissionÐ68 50 Ð
Bolts (4WD)
Rear Insulator BracketÐBolts 68 50 Ð
(4WD Automatic)
Rear Support Plate to
Transfer Case41 30 Ð
ÐBolts
Rocker ArmÐBolts 28 21 Ð
Spark Plugs 41 30 Ð
Starter MotorÐMounting
Bolts68 50 Ð
Thermostat HousingÐBolts 25 Ð 225
Throttle BodyÐBolts 23 Ð 200
Torque Converter Drive
PlateÐBolts31 Ð 270
Transfer Case to Insulator
Mounting204 150 Ð
PlateÐNuts
Transmission Support
BracketÐ68 50 Ð
Bolts (2WD)
Vibration DamperÐBolt 183 135 Ð
Water Pump to Timing Chain
Case41 30 Ð
CoverÐBolts
SPECIAL TOOLS
5.2L ENGINE
Oil Pressure Gauge C-3292
9 - 132 5.2L ENGINEDN
SPECIFICATIONS (Continued)
Downloaded from www.Manualslib.com manuals search engine SPECIFICATIONS
TORQUE CHART 5.9L ENGINE
DESCRIPTION N´m Ft. In.
Lbs. Lbs.
Camshaft SprocketÐBolt 68 50 Ð
Camshaft Thrust PlateÐBolts 24 Ð 210
Timing Chain Case CoverÐ
Bolts41 30 Ð
Connecting Rod CapÐBolts 61 45 Ð
Main Bearing CapÐBolts 115 85 Ð
Crankshaft PulleyÐBolts 24 Ð 210
Cylinder HeadÐBolts
Step 1 68 50 Ð
Step 2 143 105 Ð
Cylinder Head CoverÐBolts 11 Ð 95
Engine Support Bracket to
BlockÐ41 30 Ð
Bolts (4WD)
Exhaust Manifold to Cylinder
HeadÐ34 25 Ð
Bolts/Nuts
FlywheelÐBolts 75 55 Ð
Front InsulatorÐThrough
bolt/nut95 70 Ð
Front Insulator to Support
Bracket
ÐStud Nut (4WD) 41 30 Ð
ÐThrough Bolt/Nut (4WD) 102 75 Ð
Front Insulator to BlockÐ
Bolts (2WD)95 70 Ð
GeneratorÐMounting Bolt 41 30 Ð
Intake ManifoldÐBolts Refer to Procedure
Oil PanÐBolts 24 Ð 215
Oil PanÐDrain Plug 34 25 Ð
Oil PumpÐAttaching Bolts 41 30 Ð
Oil Pump CoverÐBolts 11 Ð 95
Rear Insulator to BracketÐ 68 50 Ð
Through-Bolt (2WD)
Rear Insulator to
Crossmember41 30 Ð
Support BracketÐNut (2WD)
Rear Insulator to
CrossmemberÐ68 50 Ð
Nuts (4WD)
DESCRIPTION N´m Ft. In.
Lbs. Lbs.
Rear Insulator to
TransmissionÐ68 50 Ð
Bolts (4WD)
Rear Insulator BracketÐBolts 68 50 Ð
(4WD Automatic)
Rear Support Bracket to 41 30 Ð
Crossmember FlangeÐNuts
Rear Support Plate to
Transfer41 30 Ð
CaseÐBolts
Rocker ArmÐBolts 28 21 Ð
Spark Plugs 41 30 Ð
Starter MotorÐMounting Bolts 68 50 Ð
Thermostat HousingÐBolts 25 Ð 225
Throttle BodyÐBolts 23 Ð 200
Torque Converter Drive
PlateÐBolts31 Ð 270
Transfer Case to Insulator 204 105 Ð
Mounting PlateÐNuts
Transmission Support
BracketÐ68 50 Ð
Bolts (2WD)
Vibration DamperÐBolt 244 180 Ð
Water Pump to Timing Chain 41 30 Ð
Case CoverÐBolts
SPECIAL TOOLS
5.9L ENGINE
Oil Pressure Gauge C-3292
DN5.9L ENGINE 9 - 189
SPECIFICATIONS (Continued)