(1) Perform the Fuel Pressure Release Procedure
(Refer to 14 - FUEL SYSTEM/FUEL DELIVERY -
STANDARD PROCEDURE).
(2) Disconnect the negative cable(s) from the bat-
tery.
(3) Inspect air cleaner, induction system, and
intake manifold to ensure system is dry and clear of
foreign material.
(4) Place a shop towel around the spark plugs to
catch any fluid that may possibly be under pressure
in the cylinder head. Remove the spark plugs.
(5) With all spark plugs removed, rotate the crank-
shaft using a breaker bar and socket.
(6) Identify the fluid in the cylinders (coolant, fuel,
oil, etc.).
(7) Be 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 a small amount of engine oil into the
cylinders to lubricate the walls. This will prevent
damage on restart.
(10) Install new spark plugs. Tighten the spark
plugs to 41 N´m (30 ft. lbs.) torque.
(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. (Refer to LUBRICATION &
MAINTENANCE - SPECIFICATIONS).
(15) Connect the negative cable(s) to the battery.
(16) Start the engine and check for any leaks.
REMOVAL
(1) Remove the battery.
(2) Drain cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(3) Discharge the air conditioning system, if
equipped (Refer to 24 - HEATING & AIR CONDI-
TIONING/PLUMBING - STANDARD PROCEDURE).
(4) Remove the upper crossmember.
(5) Remove the transmission oil cooler (Refer to 7 -
COOLING/TRANSMISSION/TRANS COOLER -
REMOVAL).
(6) Remove the serpentine belt (Refer to 7 - COOL-
ING/ACCESSORY DRIVE/DRIVE BELTS - REMOV-
AL).
(7) Remove the A/C compressor with the lines
attached (Refer to 24 - HEATING & AIR CONDI-
TIONING/PLUMBING/A/C COMPRESSOR -
REMOVAL). Set aside.
(8) If equipped, remove the condenser (Refer to 24
- HEATING & AIR CONDITIONING/PLUMBING/
A/C CONDENSER - REMOVAL).(9) Remove the washer fluid reservoir bottle (Refer
to 8 - ELECTRICAL/WIPERS/WASHERS -
REMOVAL AND INSTALLATION).
(10) Disconnect the top radiator hose.
(11) Remove the fan (Refer to 7 - COOLING/EN-
GINE/RADIATOR FAN - REMOVAL).
(12) Remove the fan shroud.
(13) Disconnect the lower radiator hose.
(14) Disconnect the transmission cooler lines.
(15) Remove radiator (Refer to 7 - COOLING/EN-
GINE/RADIATOR - REMOVAL).
(16) Remove the generator with the wire connec-
tions (Refer to 8 - ELECTRICAL/CHARGING/GEN-
ERATOR - REMOVAL).
(17) Remove the air cleaner.
(18) Disconnect the throttle linkage.
(19) Remove throttle body (Refer to 14 - FUEL
SYSTEM/FUEL INJECTION/THROTTLE BODY -
REMOVAL).
(20) Remove the upper intake manifold (Refer to 9
- ENGINE/MANIFOLDS/INTAKE MANIFOLD -
REMOVAL).
(21) Remove the coil assemblies with the ignition
cables.
(22) Disconnect the heater hoses.
(23) Disconnect the power steering hoses, if
equipped.
(24) Perform the Fuel System Pressure release
procedure (Refer to 14 - FUEL SYSTEM/FUEL
DELIVERY - STANDARD PROCEDURE). Disconnect
the fuel line (Refer to 14 - FUEL SYSTEM/FUEL
DELIVERY/QUICK CONNECT FITTING - STAN-
DARD PROCEDURE).
(25) On Manual Transmission vehicles, remove the
shift lever.
(26) Raise and support the vehicle on a hoist.
(27) Remove the drain plug and drain the engine
oil.
(28) Loosen front engine mount thru-bolt nuts.
(29) Remove the transmission cooler line brackets
from oil pan.
(30) Disconnect exhaust pipe at manifold.
(31) Disconnect the starter wires. Remove starter
motor (Refer to 8 - ELECTRICAL/STARTING/
STARTER MOTOR - REMOVAL).
(32) Remove transmission.
(33) Lower vehicle.
CAUTION: DO NOT lift the engine by the intake
manifold.
(34) Install an engine lifting fixture.
(35) Remove engine from vehicle and install
engine assembly on a repair stand.
BR/BEENGINE 8.0L 9 - 67
ENGINE 8.0L (Continued)
INSTALLATION
(1) Remove engine from the repair stand and posi-
tion in the engine compartment. Position the thru-
bolt into the support cushion brackets.
(2) Install an engine support fixture.
(3) Raise and support the vehicle on a hoist.
(4) Install Transmission.
(5) Install the starter and connect the starter
wires (Refer to 8 - ELECTRICAL/STARTING/
STARTER MOTOR - INSTALLATION).
(6) Install exhaust pipe to manifold.
(7) Install the transmission cooler line brackets
from oil pan.
(8) Tighten the Front mount thru-bolts and nuts to
102N´m (75 ft. lbs.).
(9) Install the drain plug and tighten to 34 N´m
(25 ft. lbs.) torque.
(10) Prime oil pump by squirting oil in the oil fil-
ter mounting hole and filling the J-trap of the front
timing cover. When oil is running out, install oil filter
that has been filled with oil.
(11) Lower the vehicle.
(12) Remove engine lifting fixture.
(13) On Manual Transmission vehicles, install the
shift lever.
(14) Connect the fuel lines (Refer to 14 - FUEL
SYSTEM/FUEL DELIVERY/QUICK CONNECT FIT-
TING - STANDARD PROCEDURE).
(15) Connect the heater hoses.
(16) Install the upper intake manifold (Refer to 9 -
ENGINE/MANIFOLDS/INTAKE MANIFOLD -
INSTALLATION).
(17) Install the coil assemblies with the ignition
cables.
(18) Using a new gasket, install throttle body
(Refer to 14 - FUEL SYSTEM/FUEL INJECTION/
THROTTLE BODY - INSTALLATION).
(19) Connect the throttle linkage.
(20) Install the air cleaner box.
(21) Install the generator and wire connections
(Refer to 8 - ELECTRICAL/CHARGING/GENERA-
TOR - INSTALLATION).
(22) Install the upper crossmember.
(23) Install radiator (Refer to 7 - COOLING/EN-
GINE/RADIATOR - INSTALLATION).
(24) Connect the lower radiator hose.
(25) Install the transmission oil cooler (Refer to 7 -
COOLING/TRANSMISSION/TRANS COOLER -
INSTALLATION).
(26) Connect the transmission cooler lines.
(27) Connect the power steering hoses, if equipped.
(28) Install the fan shroud.
(29) Install the fan (Refer to 7 - COOLING/EN-
GINE/RADIATOR FAN - INSTALLATION).
(30) Connect the top radiator hose.(31) Install the washer fluid reservoir bottle (Refer
to 8 - ELECTRICAL/WIPERS/WASHERS - INSTAL-
LATION).
(32) If equipped, install the condenser (Refer to 24
- HEATING & AIR CONDITIONING/PLUMBING/
A/C CONDENSER - INSTALLATION).
(33) Install the A/C compressor with the lines
attached (Refer to 24 - HEATING & AIR CONDI-
TIONING/PLUMBING/A/C COMPRESSOR -
INSTALLATION).
(34) Install the serpentine belt (Refer to 7 - COOL-
ING/ACCESSORY DRIVE/DRIVE BELTS - INSTAL-
LATION).
(35) Evacuate (Refer to 24 - HEATING & AIR
CONDITIONING/PLUMBING - STANDARD PRO-
CEDURE) and charge the air conditioning system, if
equipped (Refer to 24 - HEATING & AIR CONDI-
TIONING/PLUMBING - STANDARD PROCEDURE).
(36) Add coolant to the cooling system (Refer to 7 -
COOLING - STANDARD PROCEDURE).
(37) Install the battery.
(38) Warm engine and adjust as required.
(39) Road test vehicle.
SPECIFICATIONS
8.OL ENGINE
DESCRIPTION SPECIFICATION
CAMSHAFT
Bearing Diameter
No. 1 53.16 ± 53.19 mm
(2.093 ± 2.094 in.)
No. 2 52.76 ± 52.78 mm
(2.077 ± 2.078 in.)
No. 3 52.35 ± 52.37 mm
No. 4 51.94 ± 51.97 mm
(2.045 ± 2.046 in.)
No. 5 51.54 ± 51.56 mm
(2.029 ± 2.030 in.)
No. 6 48.74 ± 48.77 mm
(1.919 ± 1.920 in.)
Bearing Journal Diameter
No. 1 53.11 ± 53.14 mm
(2.091 ± 2.092 in.)
No. 2 52.69 ± 52.72 mm
9 - 68 ENGINE 8.0LBR/BE
ENGINE 8.0L (Continued)
(2) Use extream care and clean all gasket resdue
from the retainer.
(3) Apply a small amount of MopartSilicone Rub-
ber Adhesive Sealant to the retainer gasket. Position
the gasket onto the retainer.
(4) Position Special Tool 6687 Seal Guide onto the
crankshaft.
(5) Position the retainer and seal over the guide
and onto the engine block.
(6) Install the retainer mounting bolts. Tighten the
bolts to 22 N´m (16 ft. lbs.).
(7) Install the oil pan (Refer to 9 - ENGINE/LU-
BRICATION/OIL PAN - INSTALLATION).
(8) Install the drive plate / flywheel.
(9) Install the transmission.
(10) Check and verify engine oil level.
(11) Start engine and check for leaks.
HYDRAULIC LIFTERS
DIAGNOSIS AND TESTINGÐHYDRAULIC
TAPPETS
Before disassembling any part of the engine to cor-
rect tappet noise, check the oil pressure. If vehicle
has no oil pressure gauge, install a reliable gauge at
the pressure sending-unit. The pressure should be
between 207-552 kPa (30-80 psi) at 3,000 RPM.
Check the oil level after the engine reaches normal
operating temperature. Allow 5 minutes to stabilize
oil level, check dipstick. The oil level in the pan
should never be above the FULL mark or below the
ADD OIL mark on dipstick. Either of these two con-
ditions could be responsible for noisy tappets.
OIL LEVEL
HIGH
If oil level is above the FULL mark, it is possible
for the connecting rods to dip into the oil. With the
engine running, this condition could create foam in
the oil pan. Foam in oil pan would be fed to the
hydraulic tappets by the oil pump causing them to
lose length and allow valves to seat noisily.
LOW
Low oil level may allow oil pump to take in air.
When air is fed to the tappets, they lose length,
which allows valves to seat noisily. Any leaks on
intake side of oil pump through which air can be
drawn will create the same tappet action. Check the
lubrication system from the intake strainer to the
pump cover, including the relief valve retainer cap.
When tappet noise is due to aeration, it may be
intermittent or constant, and usually more than one
tappet will be noisy. When oil level and leaks havebeen corrected, operate the engine at fast idle. Run
engine for a sufficient time to allow all of the air
inside the tappets to be bled out.
TAPPET NOISE DIAGNOSIS
(1) To determine source of tappet noise, operate
engine at idle with cylinder head covers removed.
(2) Feel each valve spring or rocker arm to detect
noisy tappet. The noisy tappet will cause the affected
spring and/or rocker arm to vibrate or feel rough in
operation.
NOTE: Worn valve guides or cocked springs are
sometimes mistaken for noisy tappets. If such is
the case, noise may be dampened by applying side
thrust on the valve spring. If noise is not apprecia-
bly reduced, it can be assumed the noise is in the
tappet. Inspect the rocker arm push rod sockets
and push rod ends for wear.
(3) Valve tappet noise ranges from light noise to a
heavy click. A light noise is usually caused by exces-
sive leak-down around the unit plunger, or by the
plunger partially sticking in the tappet body cylinder.
The tappet should be replaced. A heavy click is
caused by a tappet check valve not seating, or by for-
eign particles wedged between the plunger and the
tappet body. This will cause the plunger to stick in
the down position. This heavy click will be accompa-
nied by excessive clearance between the valve stem
and rocker arm as valve closes. In either case, tappet
assembly should be removed for inspection and clean-
ing.
(4) The valve train generates a noise very much
like a light tappet noise during normal operation.
Care must be taken to ensure that tappets are mak-
ing the noise. If more than one tappet seems to be
noisy, it's probably not the tappets.
LEAK-DOWN TEST
After cleaning and inspection, test each tappet for
specified leak-down rate tolerance to ensure zero-lash
operation (Fig. 36).
Swing the weighted arm of the hydraulic valve tap-
pet tester away from the ram of the Universal Leak-
Down Tester.
(1) Place a 7.925-7.950 mm (0.312-0.313 inch)
diameter ball bearing on the plunger cap of the tap-
pet.
(2) Lift the ram and position the tappet (with the
ball bearing) inside the tester cup.
(3) Lower the ram, then adjust the nose of the ram
until it contacts the ball bearing. DO NOT tighten
the hex nut on the ram.
(4) Fill the tester cup with hydraulic valve tappet
test oil until the tappet is completely submerged.
BR/BEENGINE 8.0L 9 - 91
CRANKSHAFT REAR OIL SEAL RETAINER (Continued)
37). Install the yoke retaining spider bolts and
tighten to 22 N´m (16 ft. lbs.) torque.
(4) Install the push rods in their original location.
(5) Install the rocker arms (Refer to 9 - ENGINE/
CYLINDER HEAD/ROCKER ARM / ADJUSTER
ASSY - INSTALLATION).
(6) Install lower and upper intake manifold (Refer
to 9 - ENGINE/MANIFOLDS/INTAKE MANIFOLD -
INSTALLATION).
(7) The cylinder head cover gasket can be used
again. Install the gasket onto the head rail.For the
left side the number tab is at the front of
engine with the number up. For the right side
the number tab is at the rear of engine with the
number up.
(8) Install cylinder head cover (Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - INSTALLATION).
(9) Install the air cleaner.
CAUTION: To prevent damage to valve mechanism,
engine must not be run above fast idle until all
hydraulic tappets have filled with oil and have
become quiet.
(10) Connect the negative cable to the battery.
(11) Road test vehicle and check for leaks.
PISTON & CONNECTING ROD
DESCRIPTION
The pistons (Fig. 38) are elliptically turned so that
the diameter at the pin boss is less than its diameter
across the thrust face. This allows for expansion
under normal operating conditions. Under operating
temperatures, expansion forces the pin bosses away
from each other, causing the piston to assume a more
nearly round shape.
All pistons are machined to the same weight,
regardless of size, to maintain piston balance.
The piston pin rotates in the piston only and is
retained by the press interference fit of the piston
pin in the connecting rod.
The pistons have a unique dry-film lubricant coat-
ing baked onto the skirts to reduce friction. The
lubricant is particularly effective during engine
break-in, but with time, the material becomes embed-
ded into cylinder bore walls and continues to reduce
friction.
The pistons are LH and RH bank specific.
STANDARD PROCEDUREÐPISTON FITTING
Piston and cylinder wall must be clean and dry.
Specified clearance between the piston and the cylin-
der wall is 0.013-0.038 mm (0.0005-0.0015 inch). The
max. allowable clearance is 0.0762 mm (0.003 in.).Piston diameter should be measured at the top of
skirt, 90É to piston pin axis. Cylinder bores should be
measured halfway down the cylinder bore and trans-
verse to the engine crankshaft center line.
Pistons and cylinder bores should be measured at
normal room temperature, 21ÉC (70ÉF).
(1) To correctly select the proper size piston, a cyl-
inder bore gauge, capable of reading in .00019
INCREMENTS is required (Fig. 39). If a bore gauge
is not available, do not use an inside micrometer.The
coating material is applied to the piston after the
final piston machining process. Measuring the out-
side diameter of a coated piston will not provide
accurate results. Therefore measuring the inside
diameter of the cylinder bore with a dial Bore Gauge
isMANDATORY.. To correctly select the proper size
piston, a cylinder bore gauge capable of reading in
.00019increments is required.Piston installation into
the cylinder bore require slightly more pressure than
that required for non-coated pistons. The bonded
Fig. 38 Piston and Connecting RodÐ8.0L Engine
1 - FRONT I.D. TOWARDS THIS SIDE
2 - ORIENTATION BUTTON TOWARDS REAR
(R.H. ONLY)
2, 4, 6, 8, 10
3 - ORIENTATION BUTTON TOWARDS FRONT
(L.H. ONLY)
1, 3, 5, 7, 9
BR/BEENGINE 8.0L 9 - 93
HYDRAULIC LIFTERS (Continued)
(3) Drain engine oil.
(4) Remove left engine to transmission strut.
(5) Remove oil pan mounting bolts, pan and one-
piece gasket. The engine may have to be raised
slightly on 2WD vehicles.
(6) Remove the oil pick-up tube assembly (Fig. 56)
. Discard the gasket.
CLEANING
Clean the block and pan gasket surfaces.
If present, trim excess sealant from inside the
engine.
Clean oil pan in solvent and wipe dry with a clean
cloth.
Clean oil screen and pipe thoroughly in clean sol-
vent. Inspect condition of screen.
INSPECTION
Inspect oil drain plug and plug hole for stripped or
damaged threads. Repair as necessary.
Inspect oil pan mounting flange for bends or distor-
tion. Straighten flange, if necessary.
INSTALLATION
(1) Fabricate 4 alignment dowels from 5/16x11/2
inch bolts. Cut the head off the bolts and cut a slot
into the top of the dowel. This will allow easier
installation and removal with a screwdriver (Fig. 57)
.
(2) Install the dowels in the cylinder block at the
four corners.
(3) Apply small amount of MopartSilicone Rubber
Adhesive Sealant, or equivalent at the split lines.
The split lines are between the cylinder block, the
timing chain cover and the rear crankshaft seal
assembly (Fig. 56) .After the sealant is appliedyou have 3 minutes to install the gasket and oil
pan.
(4) Slide the one-piece gasket over the dowels and
onto the block.
(5) Position the oil pan over the dowels and onto
the gasket. The engine may have to be slightly raised
on 2WD vehicles.
(6) Install the oil pan bolts (Fig. 58) . Tighten the
bolts to as shown in Oil Pan Bolts Torque Chart.
(7) Remove the dowels. Install the remaining 5/16
inch oil pan bolts. Torque these bolts as shown in Oil
Pan Bolts Torque Chart.
(8) Install the drain plug. Tighten drain plug to 34
N´m (25 ft. lbs.) torque.
(9) Install the engine to transmission strut.
(10) Lower vehicle.
(11) Connect the negative cable to the battery.
(12) Fill crankcase with oil to proper level.
(13) Start engine and check for leaks.
Fig. 56 Oil Pick-Up Tube
1 - PICKÐUP TUBE
2 - SEALANT AT SPLIT-LINES
3 - SEALANT AT SPLIT-LINE
Fig. 57 Fabrication of Alignment Dowels
1 - 5/16º X 1óº BOLT
2 - DOWEL
3 - SLOT
Fig. 58 Oil Pan Bolt Location
1 - OIL PAN
2 - OIL FILTER
3 - STUD BOLTS
4 - DRAIN PLUG
BR/BEENGINE 8.0L 9 - 103
OIL PAN (Continued)
(15) Install the fuel lines (Refer to 14 - FUEL SYS-
TEM/FUEL DELIVERY/QUICK CONNECT FIT-
TING - STANDARD PROCEDURE).
(16) Using a new gasket, install the air cleaner
housing. Tighten the nuts to 11 N´m (96 in. lbs.)
torque. Install the air cleaner filter and cover.
(17) Install the A/C compressor (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING/A/C
COMPRESSOR - INSTALLATION). Position the com-
pressor brace and install the bolts. Tighten the brace
bolts to 41 N´m (30 ft. lbs.) torque.
(18) Install the generator (Refer to 8 - ELECTRI-
CAL/CHARGING/GENERATOR - INSTALLATION).
Position the generator brace and install the bolts.
Tighten the brace bolts to 41 N´m (30 ft. lbs.) torque.
(19) Install the accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
INSTALLATION).
(20) Fill cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(21) Connect the negative cable to the battery.
(22) Start engine check for leaks.
EXHAUST MANIFOLD
DESCRIPTION
Engine exhaust manifolds (Fig. 75) are made of
high molybdenum ductile cast iron. A special ribbed
design helps control permanent dimensional changes
during heat cycles.
OPERATION
The exhaust manifolds collect the engine exhaust
exiting the combustion chambers, then channels the
exhaust gases to the exhaust pipes attached to the
manifolds.
REMOVAL
(1) Disconnect the negative cable from the battery.
(2) Raise and support the vehicle.
(3) Remove the bolts and nuts attaching the
exhaust pipe to the engine exhaust manifold..
(4) Lower the vehicle.
(5) Remove the exhaust heat shields (Fig. 76).
(6) Remove the dipstick bracket from the exhaust
manifold (right side only).
(7) Remove bolts attaching manifold to cylinder
head.
(8) Remove manifold from the cylinder head. Dis-
card the gasket.
CLEANING
Clean mating surfaces on cylinder head and mani-
fold. Wash with solvent and blow dry with com-
pressed air.
INSPECTION
Inspect manifold for cracks.
Inspect mating surfaces of manifold for flatness
with a straight edge. Gasket surfaces must be flat
within 0.2 mm per 300 mm (0.008 inch per foot).
INSTALLATION
(1) Using a new gasket position the engine
exhaust manifold onto the cylinder head. Install bolts
and stud bolts in the proper position (Fig. 76).
Tighten the bolts to 22 N´m (16 ft. lbs.) torque.
Fig. 75 Exhaust ManifoldÐ8.0L Engine
1 - EXHAUST MANIFOLD
Fig. 76 8.0L Engine Exhaust ManifoldÐTypical
1 - EXHAUST MANIFOLD
2 - HEAT SHIELD
BR/BEENGINE 8.0L 9 - 109
INTAKE MANIFOLD (Continued)
(6) Prime oil pump by squirting oil in the oil filter
mounting hole and filling the J-trap of the front tim-
ing cover. When oil is running out, install oil filter
that has been filled with oil.
(7) Install water pump and housing assembly
using new o-ring (Refer to 7 - COOLING/ENGINE/
WATER PUMP - INSTALLATION).
(8) Install generator, air pump, and bracket assem-
bly.
(9) Install A/C compressor (Refer to 24 - HEATING
& AIR CONDITIONING/PLUMBING/A/C COM-
PRESSOR - INSTALLATION).
(10) (10) Install the radiator fan (Refer to 7 -
COOLING/ENGINE/RADIATOR FAN - INSTALLA-
TION).
(11) Position the fan shroud and install the bolts.
Tighten the bolts to 11 N´m (95 in. lbs.) torque.
(12) Install the serpentine belt (Refer to 7 - COOL-
ING/ACCESSORY DRIVE/DRIVE BELTS - INSTAL-
LATION).
(13) Fill cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(14) Connect the negative cable to the battery.
(15) Road test vehicle and check for leaks.
TIMING BELT/CHAIN AND
SPROCKETS
REMOVAL
(1) Remove timing chain cover and gasket using
extreme caution to avoid damaging oil pan gasket
(Refer to 9 - ENGINE/VALVE TIMING/TIMING
BELT / CHAIN COVER(S) - REMOVAL).
(2) Aline camshaft and crankshaft centerline.
Remove camshaft sprocket attaching bolt and remove
timing chain and camshaft sprockets.
(3) Use puller 6444 and jaws 6820 to remove
crankshaft sprocket (Fig. 79).
INSPECTIONÐMEASURING TIMING CHAIN
STRETCH
(1) Place a scale next to the timing chain so that
any movement of the chain may be measured.
(2) Place a torque wrench and socket over cam-
shaft sprocket attaching bolt. Apply torque in the
direction of crankshaft rotation to take up slack; 41
N´m (30 ft. lbs.) torque with cylinder head installed
or 20 N´m (15 ft. lbs.) torque with cylinder head
removed. With a torque applied to the camshaft
sprocket bolt, crankshaft should not be permitted to
move. It may be necessary to block the crankshaft to
prevent rotation.
(3) Hold a scale with dimensional reading even
with the edge of a chain link. With cylinder heads
installed, apply 14 N´m (30 ft. lbs.) torque in thereverse direction. With the cylinder heads removed,
apply 20 N´m (15 ft. lbs.) torque in the reverse direc-
tion. Note the amount of chain movement (Fig. 80).
(4) Install a new timing chain, if its movement
exceeds 3.175 mm (1/8 inch).
INSTALLATION
(1) Line up key in crankshaft with keyway in
sprocket, press on crankshaft timing sprocket, use
tools C-3688, C-3718 and MB-990799, seat sprocket
against crankshaft shoulder (Fig. 81).
Fig. 79 Crankshaft Sprocket Removal.
1 - SPECIAL TOOL 6444
2 - SPECIAL TOOL 6820
Fig. 80 Measuring Timing Chain Stretch
1 - TORQUE WRENCH
2 - 3.175 MM
(0.125 IN.)
BR/BEENGINE 8.0L 9 - 111
TIMING BELT / CHAIN COVER(S) (Continued)
CONDITION POSSIBLE CAUSES CORRECTION
LUBRICATING OIL
PRESSURE TOO HIGH1. Pressure switch/gauge not
operating properly.1. Verify pressure switch is functioning
correctly. If not, replace switch/gauge.
2. Engine running to cold. 2. Refer to Coolant Temperature Below
Normal (Refer to 7 - COOLING -
DIAGNOSIS AND TESTING).
3. Oil viscosity too thick. 3. Make sure the correct oil is being used.
(Refer to LUBRICATION &
MAINTENANCE/FLUID TYPES -
DESCRIPTION).
4. Oil pressure relief valve stuck
closed or binding4. Check and replace valve.
LUBRICATING OIL LOSS 1. External leaks. 1. Visually inspect for oil leaks. Repair as
required.
2. Crankcase being overfilled. 2. Verify that the correct dipstick is being
used.
3. Incorrect oil specification or
viscosity.3. (a) Make sure the correct oil is being
used (Refer to LUBRICATION &
MAINTENANCE/FLUID TYPES -
DESCRIPTION).
(b) Look for reduced viscosity from dilution
with fuel.
(c) Review/reduce oil change intervals.
4. Oil cooler leak 4. Check and replace the oil cooler.
5. High blow-by forcing oil out the
breather.5. Check the breather tube area for signs of
oil loss. Perform the required repairs.
6. Turbocharger leaking oil to the air
intake.6. Inspect the air ducts for evidence of oil
transfer. Repair as required.
7. Piston rings not sealing (oil being
consumed by the engine).7. Perform blow-by check. Repair as
required.
COMPRESSION KNOCKS 1. Air in the fuel system. 1. Bleed the fuel system (Refer to 14 -
FUEL SYSTEM/FUEL DELIVERY -
STANDARD PROCEDURE).
2. Poor quality fuel or water/gasoline
contaminated fuel.2. Verify by operating from a temporary
tank with good fuel. Clean and flush the
fuel tank. Replace fuel/water separator filter.
3. Engine overloaded. 3. Verify the engine load rating is not being
exceeded.
4. Incorrect injection pump timing. 4. Check injection pump for proper
installation.
5. Improperly operating injectors. 5. Check and replace inoperative injectors.
EXCESSIVE VIBRATION 1. Loose or broken engine mounts. 1. Replace engine mounts.
2. Damaged fan or improperly
operating accessories.2. Check and replace the vibrating
components.
3. Improperly operating vibration
damper3. Inspect/replace vibration damper.
BR/BEENGINE 5.9L DIESEL 9 - 117
ENGINE 5.9L DIESEL (Continued)