2003 DODGE RAM overheating

þ Loss of engine power
þ Engine misfiring
þ Poor fuel economy
²Possible indications of the cylinder head gasket
leaking between a cylinder and an adjacent water
jacket are:
þ Engine overheating
þ Loss of coolant
þ Excessive steam (white smoke) emitting from
exhaust
þ Coolant foaming
CYLINDER-TO-CYLINDER LEAKAGE TEST
To determine if an engine cylinder head gasket is
leaking between adjacent cylinders, follow the proce-
dures in Cylinder Compression Pressure Test in this
section. An engine cylinder head gasket leaking
between adjacent cylinders will result in approxi-
mately a 50±70% reduction in compression pressure.
CYLINDER-TO-WATER JACKET LEAKAGE TEST
WARNING: USE EXTREME CAUTION WHEN THE
ENGINE IS OPERATING WITH COOLANT PRES-
SURE CAP REMOVED.
VISUAL TEST METHOD
With the engine cool, remove the coolant pressure
cap. Start the engine and allow it to warm up until
thermostat opens.
If a large combustion/compression pressure leak
exists, bubbles will be visible in the coolant.
COOLING SYSTEM TESTER METHOD
WARNING: WITH COOLING SYSTEM TESTER IN
PLACE, PRESSURE WILL BUILD UP FAST. EXCES-
SIVE PRESSURE BUILT UP, BY CONTINUOUS
ENGINE OPERATION, MUST BE RELEASED TO A
SAFE PRESSURE POINT. NEVER PERMIT PRES-
SURE TO EXCEED 138 kPa (20 psi).
Install Cooling System Tester 7700 or equivalent to
pressure cap neck. Start the engine and observe the
tester's pressure gauge. If gauge pulsates with every
power stroke of a cylinder a combustion pressure
leak is evident.
CHEMICAL TEST METHOD
Combustion leaks into the cooling system can also
be checked by using Bloc-Chek Kit C-3685-A or
equivalent. Perform test following the procedures
supplied with the tool kit.
REMOVAL
(1) Disconnect the battery negative cable.
(2) Drain cooling system.
(3) Remove the air cleaner resonator and duct
work.
(4) Remove the generator.
(5) Remove closed crankcase ventilation system.
(6) Disconnect the evaporation control system.
(7) Perform the Fuel System Pressure Release pro-
cedure (Refer to 14 - FUEL SYSTEM/FUEL DELIV-
ERY - STANDARD PROCEDURE). Disconnect the
fuel supply line (Refer to 14 - FUEL SYSTEM/FUEL
DELIVERY/QUICK CONNECT FITTING - STAN-
DARD PROCEDURE).
(8) Disconnect heater hoses.
(9) Remove cylinder head covers and gaskets.
(10) Remove intake manifold and throttle body as
an assembly.
(11) Remove rocker arm assemblies and push rods.
Identify to ensure installation in original locations.
(12) Remove the head bolts from each cylinder
head and remove cylinder heads. Discard the cylin-
der head gasket.
CLEANING
Clean all surfaces of cylinder block and cylinder
heads.
Clean cylinder block front and rear gasket surfaces
using a suitable solvent.
INSPECTION
(1) Inspect the cylinder head for out-of-flatness,
using a straightedge and a feeler gauge. If tolerances
exceed 0.0508 mm (0.002 in.) replace the cylinder
head.
(2) Inspect the valve seats for damage. Service the
valve seats as necessary.
(3) Inspect the valve guides for wear, cracks or
looseness. If either condition exist, replace the cylin-
der head.
(4) Inspect pushrods. Replace worn or bent push-
rods.
INSTALLATION
(1) Clean all surfaces of cylinder block and cylin-
der heads.
(2) Clean cylinder block front and rear gasket sur-
faces using a suitable solvent.
CAUTION: The head gaskets are not interchange-
able between left and right sides. They are marked
ªLº and ªRº to indicate left and right sides.
(3) Position new cylinder head gaskets onto the
cylinder block.
DRENGINE - 5.7L 9 - 195
CYLINDER HEAD (Continued)

CYLINDER HEAD
DESCRIPTION
DESCRIPTIONÐCYLINDER HEAD
The cast iron cylinder heads (Fig. 6) are mounted
to the cylinder block using ten bolts. The spark plugs
are located in the peak of the wedge between the
valves.
DESCRIPTION - CYLINDER HEAD COVER
GASKET
The cylinder head cover gasket (Fig. 7) is a steel-
backed silicone gasket, designed for long life usage.
OPERATION
OPERATIONÐCYLINDER HEAD
The cylinder head closes the combustion chamber
allowing the pistons to compress the air fuel mixture
to the correct ratio for ignition. The valves located in
the cylinder head open and close to either allow clean
air into the combustion chamber or to allow the
exhaust gases out, depending on the stroke of the
engine.
OPERATION - CYLINDER HEAD COVER
GASKET
The steel-backed silicone gasket is designed to seal
the cylinder head cover for long periods of time
through extensive heat and cold, without failure. The
gasket is designed to be reusable.
DIAGNOSIS AND TESTINGÐCYLINDER HEAD
GASKET FAILURE
A cylinder head gasket leak can be located between
adjacent cylinders or between a cylinder and the
adjacent water jacket.
²Possible indications of the cylinder head gasket
leaking between adjacent cylinders are:
þ Loss of engine power
þ Engine misfiring
þ Poor fuel economy
²Possible indications of the cylinder head gasket
leaking between a cylinder and an adjacent water
jacket are:
þ Engine overheating
þ Loss of coolant
þ Excessive steam (white smoke) emitting from
exhaust
þ Coolant foaming
CYLINDER-TO-CYLINDER LEAKAGE TEST
To determine if an engine cylinder head gasket is
leaking between adjacent cylinders, follow the proce-
dures in Cylinder Compression Pressure Test in this
section. An engine cylinder head gasket leaking
between adjacent cylinders will result in approxi-
mately a 50±70% reduction in compression pressure.
CYLINDER-TO-WATER JACKET LEAKAGE TEST
WARNING: USE EXTREME CAUTION WHEN THE
ENGINE IS OPERATING WITH COOLANT PRES-
SURE CAP REMOVED.
VISUAL TEST METHOD
With the engine cool, remove the coolant pressure
cap. Start the engine and allow it to warm up until
thermostat opens.
Fig. 6 Cylinder Head AssemblyÐV-8 Gas Engines
1 - EXHAUST VALVE
2 - SPARK PLUGS
3 - EXHAUST VALVES
4 - SPARK PLUGS
5 - EXHAUST VALVE
6 - INTAKE VALVES
7 - INTAKE VALVES
Fig. 7 Cylinder Head Cover Gasket V-8 Gas Engines
1 - CYLINDER HEAD COVER GASKET
DRENGINE - 5.9L 9 - 243

²Possible indications of the cylinder head gasket
leaking between a cylinder and an adjacent water
jacket are:
þ Engine overheating
þ Loss of coolant
þ Excessive steam (white smoke) emitting from
exhaust
þ Coolant foaming
CYLINDER-TO-CYLINDER LEAKAGE TEST
To determine if an engine cylinder head gasket is
leaking between adjacent cylinders, follow the proce-
dures in Cylinder Compression Pressure Test in this
section. An engine cylinder head gasket leaking
between adjacent cylinders will result in approxi-
mately a 50±70% reduction in compression pressure.
CYLINDER-TO-WATER JACKET LEAKAGE TEST
WARNING: USE EXTREME CAUTION WHEN THE
ENGINE IS OPERATING WITH COOLANT PRES-
SURE CAP REMOVED.
VISUAL TEST METHOD
With the engine cool, remove the coolant pressure
cap. Start the engine and allow it to warm up until
thermostat opens.
If a large combustion/compression pressure leak
exists, bubbles will be visible in the coolant.COOLING SYSTEM TESTER METHOD
WARNING: WITH COOLING SYSTEM TESTER IN
PLACE, PRESSURE WILL BUILD UP FAST. EXCES-
SIVE PRESSURE BUILT UP, BY CONTINUOUS
ENGINE OPERATION, MUST BE RELEASED TO A
SAFE PRESSURE POINT. NEVER PERMIT PRES-
SURE TO EXCEED 138 kPa (20 psi).
Install Cooling System Tester 7700 or equivalent to
pressure cap neck. Start the engine and observe the
tester's pressure gauge. If gauge pulsates with every
power stroke of a cylinder a combustion pressure
leak is evident.
CHEMICAL TEST METHOD
Combustion leaks into the cooling system can also
be checked by using Bloc-Chek Kit C-3685-A or
equivalent. Perform test following the procedures
supplied with the tool kit.
REMOVAL
(1) Disconnect the negative cable from the battery.
(2) Drain cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(3) Remove the heat shields (Fig. 7).
(4) Remove the intake manifold-to-generator
bracket support rod. Remove the generator (Refer to
8 - ELECTRICAL/CHARGING/GENERATOR -
REMOVAL).
(5) Remove closed crankcase ventilation system.
(6) Disconnect the evaporation control system.
(7) Remove the air cleaner.
(8) Perform the Fuel System Pressure release pro-
cedure (Refer to 14 - FUEL SYSTEM/FUEL DELIV-
ERY - STANDARD PROCEDURE). Disconnect the
Fig. 6 Cylinder Head Assembly
1 - SPARK PLUG
2 - INTAKE VALVES
3 - SPARK PLUG
4 - INTAKE VALVES
5 - SPARK PLUG
6 - SPARK PLUG
7 - INTAKE VALVE
8 - SPARK PLUG
9 - EXHAUST VALVE
10 - EXHAUST VALVES
11 - EXHAUST VALVES
Fig. 7 Spark Plug Wire Heat Shields (Left Side
Shown)
1 - EXHAUST MANIFOLD
2 - HEAT SHIELD
DRENGINE 8.0L 9 - 371
CYLINDER HEAD (Continued)

SPECIFICATIONS - TORQUE
DESCRIPTION N´m Ft. In.
Lbs. Lbs.
Adjusting StrapÐBolt 23 Ð 200
Air Heater Power SupplyÐ
Nuts14 Ð 124
Air Inlet HousingÐBolts 24 18 Ð
Cab Heater Supply/Return
LineÐNuts24 18 Ð
Exhaust ClampÐNuts 48 35 Ð
Exhaust Manifold to Cylinder
HeadÐBolts
(Diesel Engine) 43 32 Ð
Exhaust Manifold to Cylinder
HeadÐBolts
(5.9L) 31 23 Ð
Exhaust Manifold to Cylinder
HeadÐBolts
(8.0L) 22 Ð 195
Exhaust Pipe to ManifoldÐ
Bolts31 23 Ð
Generator MountingÐBolts 41 30 Ð
Charge Air Cooler
MountingÐBolts2Ð17
Charge Air Cooler DuctÐ
Nuts11 Ð 9 5
Heat ShieldÐNuts and Bolts 11 Ð 95
Turbocharger flange studs 24 18 Ð
Turbocharger MountingÐ
Nuts43 32 Ð
Turbocharger Oil Drain
TubeÐBolts24 18 Ð
Turbocharger Oil Supply
LineÐFitting24 18 Ð
Turbocharger V-Band
ClampÐNut9Ð75
Turbocharger Oil Supply
fitting (at Turbocharger)36 27 Ð
Turbocharger Oil Supply
fitting (at lube filter head)24 18 Ð
Turbocharger Drain Hose
Clamps8Ð71
SPECIAL TOOLS
CATALYTIC CONVERTER
DESCRIPTION - CATALYTIC CONVERTER
WARNING: THE NORMAL OPERATING TEMPERA-
TURE OF THE EXHAUST SYSTEM IS VERY HIGH.
THEREFORE, NEVER WORK AROUND OR ATTEMPT
TO SERVICE ANY PART OF THE EXHAUST SYSTEM
UNTIL IT IS COOLED. SPECIAL CARE SHOULD BE
TAKEN WHEN WORKING NEAR THE CATALYTIC
CONVERTER. THE TEMPERATURE OF THE CON-
VERTER RISES TO A HIGH LEVEL AFTER A SHORT
PERIOD OF ENGINE OPERATION TIME.
CAUTION: DO NOT remove spark plug wires from
plugs or by any other means short out cylinders.
Failure of the catalytic converter can occur due to a
temperature increase caused by unburned fuel
passing through the converter.
The stainless steel catalytic converter body is
designed to last the life of the vehicle. Excessive heat
can result in bulging or other distortion, but exces-
sive heat will not be the fault of the converter. If
unburned fuel enters the converter, overheating may
occur. If a converter is heat-damaged, correct the
cause of the damage at the same time the converter
is replaced. Also, inspect all other components of the
exhaust system for heat damage.
Unleaded gasoline must be used to avoid con-
taminating the catalyst core.
50 State emission vehicles incorporate two mini
catalytic converters located after the exhaust mani-
folds and before the inline catalytic converter.
OPERATION
The catalytic converter captures and burns any
unburned fuel mixture exiting the combustion cham-
bers during the exhaust stroke of the engine. This
process aids in reducing emissions output.
TURBOCHARGER TESTER 9022
11 - 4 EXHAUST SYSTEMDR
EXHAUST SYSTEM (Continued)

REMOVAL
REMOVAL
WARNING: IF TORCHES ARE USED WHEN WORK-
ING ON THE EXHAUST SYSTEM, DO NOT ALLOW
THE FLAME NEAR THE FUEL LINES.
(1) Raise and support the vehicle.
(2) Saturate the bolts and nuts with heat valve
lubricant. Allow 5 minutes for penetration.
(3) Remove the bolts from the crossover pipe to the
catalytic converter connection.
(4) Disconnect oxygen sensor wiring.
(5) Loosen the nuts from the clamp that hold the
catalytic converter to the exhaust pipe flange connec-
tion.
NOTE: Do not remove nut from T-Bolt. Only remove
nut far enough, so that the T end can be removed
from the clamp.
(6) Remove the T bolt end of the fastener, from the
clamp.
(7) Spread the clamp, and remove the catalytic
converter from the vehicle.
(8) Discard the clamp.
NOTE: The catalytic converter to exhaust manifold
clamp is not reusable. Always use a new clamp
when reinstalling the catalytic converter.
REMOVAL
(1) Raise and support vehicle.
(2) Saturate the bolts and nuts with heat valve
lubricant. Allow 5 minutes for penetration.
(3) Remove clamps and nuts.
(4) Remove the catalytic converter.
INSPECTION
Look at the stainless steel body of the converter,
inspect for bulging or other distortion that could be a
result of overheating. If the converter has a heat
shield attached make sure it is not bent or loose.
If you suspect internal damage to the catalyst, tap-
ping the bottom of the catalyst with a rubber mallet
may indicate a damaged core.
INSTALLATION
INSTALLATION
NOTE: The catalytic converter to exhaust manifold
clamp is not reusable. Always use a new clamp
when reinstalling the catalytic converter.(1) Position the catalytic converter onto the
exhaust pipe flange connection. Tighten the nuts to
28 N´m (250 in. lbs.) torque.
(2) Install the muffler onto the catalytic converter
until the alignment tab is inserted into the align-
ment slot.
(3) Install the exhaust clamp at the muffler and
catalytic converter connection. Tighten the clamp
nuts to 47 N´m (35 ft. lbs.) torque.
(4) Connect oxygen sensor wiring.
(5) Lower the vehicle.
(6) Start the engine and inspect for exhaust leaks
and exhaust system contact with the body panels.
Adjust the alignment, if needed.
INSTALLATION
(1) Assemble converter and clamps loosely in
place.
(2) Install the exhaust pipe onto exhaust mani-
folds, tighten 31 N´m (23 ft. lbs.).
(3) Tighten all clamp nuts to 48 N´m (35 ft. lbs.)
torque.
(4) Lower the vehicle.
(5) Start the engine and inspect for exhaust leaks
and exhaust system contact with the body panels. A
minimum of 25.4 mm (1.0 in.) is required between
exhaust system components and body/frame parts.
Adjust the alignment, if needed.
EXHAUST PIPE
REMOVAL
REMOVAL Ð 5.9L
(1) Raise and support the vehicle.
(2) Saturate the bolts and nuts with heat valve
lubricant. Allow 5 minutes for penetration.
(3) Remove exhaust pipe to manifold bolts, retain-
ers and nuts.
(4) Remove the clamp nuts.
(5) Remove the exhaust pipe (Fig. 1).
REMOVAL
CAUTION: When servicing or replacing exhaust
system components, disconnect the oxygen sensor
connector(s). Allowing the exhaust to hang by the
oxygen sensor wires will damage the harness
and/or sensor.
(1) Raise and support the vehicle.
(2) Saturate the bolts and nuts with MopartRust
Penetrant. Allow 5 minutes for penetration.
(3) Disconnect the oxygen sensor(s).
DREXHAUST SYSTEM 11 - 5
CATALYTIC CONVERTER (Continued)

OXYGEN SENSOR
DESCRIPTION
The Oxygen Sensors (O2S) are attached to, and
protrude into the vehicle exhaust system. Depending
on the engine or emission package, the vehicle may
use a total of either 2 or 4 sensors.
Federal Emission Packages :Two sensors are
used: upstream (referred to as 1/1) and downstream
(referred to as 1/2). With this emission package, the
upstream sensor (1/1) is located just before the main
catalytic convertor. The downstream sensor (1/2) is
located just after the main catalytic convertor.
California Emission Packages:On this emis-
sions package, 4 sensors are used: 2 upstream
(referred to as 1/1 and 2/1) and 2 downstream
(referred to as 1/2 and 2/2). With this emission pack-
age, the right upstream sensor (2/1) is located in the
right exhaust downpipe just before the mini-catalytic
convertor. The left upstream sensor (1/1) is located in
the left exhaust downpipe just before the mini-cata-
lytic convertor. The right downstream sensor (2/2) is
located in the right exhaust downpipe just after the
mini-catalytic convertor, and before the main cata-
lytic convertor. The left downstream sensor (1/2) is
located in the left exhaust downpipe just after the
mini-catalytic convertor, and before the main cata-
lytic convertor.
OPERATION
An O2 sensor is a galvanic battery that provides
the PCM with a voltage signal (0-1 volt) inversely
proportional to the amount of oxygen in the exhaust.
In other words, if the oxygen content is low, the volt-
age output is high; if the oxygen content is high the
output voltage is low. The PCM uses this information
to adjust injector pulse-width to achieve the
14.7±to±1 air/fuel ratio necessary for proper engine
operation and to control emissions.
The O2 sensor must have a source of oxygen from
outside of the exhaust stream for comparison. Cur-
rent O2 sensors receive their fresh oxygen (outside
air) supply through the O2 sensor case housing.
Four wires (circuits) are used on each O2 sensor: a
12±volt feed circuit for the sensor heating element; a
ground circuit for the heater element; a low-noise
sensor return circuit to the PCM, and an input cir-
cuit from the sensor back to the PCM to detect sen-
sor operation.
Oxygen Sensor Heater Relay - 5.9L/8.0L:If 4
oxygen sensors are used, a separate heater relay is
used to supply voltage to the sensors heating ele-
ments for only the 1/2 and 2/2 downstream sensors.
Voltage for the other 2 sensor heating elements is
supplied directly from the Powertrain Control Mod-ule (PCM) through a Pulse Width Module (PWM)
method.
Pulse Width Module (PWM) - 5.9L/8.0L:Voltage
to the O2 sensor heating elements is supplied
directly from the Powertrain Control Module (PCM)
through two separate Pulse Width Module (PWM)
low side drivers. PWM is used on both the upstream
and downstream O2 sensors if equipped with a Fed-
eral Emissions Package, and only on the 2 upstream
sensors (1/1 and 2/1) if equipped with a California
Emissions Package. The main objective for a PWM
driver is to avoid overheating of the O2 sensor heater
element. With exhaust temperatures increasing with
time and engine speed, it's not required to have a
full-voltage duty-cycle on the O2 heater elements.
To avoid the large simultaneous current surge
needed to operate all 4 sensors, power is delayed to
the 2 downstream heater elements by the PCM for
approximately 2 seconds.
Oxygen Sensor Heater Elements:
The O2 sensor uses a Positive Thermal Co-efficient
(PTC) heater element. As temperature increases,
resistance increases. At ambient temperatures
around 70ÉF, the resistance of the heating element is
approximately 13 ohms. As the sensor's temperature
increases, resistance in the heater element increases.
This allows the heater to maintain the optimum
operating temperature of approximately 930É-1100ÉF
(500É-600É C). Although the sensors operate the
same, there are physical differences, due to the envi-
ronment that they operate in, that keep them from
being interchangeable.
Maintaining correct sensor temperature at all
times allows the system to enter into closed loop
operation sooner. Also, it allows the system to remain
in closed loop operation during periods of extended
idle.
In Closed Loop operation, the PCM monitors cer-
tain O2 sensor input(s) along with other inputs, and
adjusts the injector pulse width accordingly. During
Open Loop operation, the PCM ignores the O2 sensor
input. The PCM adjusts injector pulse width based
on preprogrammed (fixed) values and inputs from
other sensors.
Upstream Sensor - Federal Emissions Pack-
age :The upstream sensor (1/1) provides an input
voltage to the PCM. The input tells the PCM the oxy-
gen content of the exhaust gas. The PCM uses this
information to fine tune fuel delivery to maintain the
correct oxygen content at the downstream oxygen
sensor. The PCM will change the air/fuel ratio until
the upstream sensor inputs a voltage that the PCM
has determined will make the downstream sensor
output (oxygen content) correct.
The upstream oxygen sensor also provides an input
to determine catalytic convertor efficiency.
DRFUEL INJECTION - GAS 14 - 43

closed and fuel flow into the combustion chamber is
stopped. Exhaust gases are prevented from entering
the injector nozzle by the needle valve.
REMOVAL
CAUTION: Refer to Cleaning Fuel System Parts.
Six individual, solenoid actuated high-pressure fuel
injectors are used (Fig. 14). The injectors are verti-
cally mounted into a bored hole in the top of the cyl-
inder head. This bored hole is located between the
intake/exhaust valves. High-pressure connectors (Fig.
15), mounted into the side of the cylinder head, con-
nect each fuel injector to each high-pressure fuel line.
(1) Disconnect both negative battery cables from
both batteries. Cover and isolate ends of cables.
(2) Remove breather assembly.
(3) Remove valve cover. Refer to Engines for proce-
dures.
(4) Remove necessary high pressure fuel line con-
necting necessary fuel injector rail to high pressure
connector. Refer to Fuel Line Removal for procedures.
(5) A connector retainer (nut) (Fig. 15) is used on
each connector tube. Remove this nut(s) by unthread-
ing from cylinder head.
(6) Using special high-pressure connector removal
tool #9015 (Fig. 16), or (Fig. 17) remove necessary
high-pressure connector(s) from cylinder head. Tool
#9015 threads onto connector tube. Use tool to pry
connector tube(s) from cylinder head.
(7) Remove necessary exhaust rocker arm assem-
bly(s).
(8) Disconnect injector solenoid wire nuts at top of
injectors (Fig. 18).
(9) Remove 2 fuel injector hold-down clamp bolts
at each injector being removed.
(10)USING TOOL #9010:
(a) Special Tool #9010 (Fig. 19) is equipped with
2 clamshell clamps, a sliding retainer sleeve to
retain the clamshell clamps, a 2±piece mounting
stud, and a pivoting handle.Do not attempt to
remove the fuel injector with any other
device. Damage to injector will occur.
(b) The rocker housing (Fig. 18) is bolted to the
top of cylinder head. The mounting stud from tool
#9010 was meant to temporarily replace a rocker
housing mounting bolt. Remove the necessary
rocker housing mounting bolt. These mounting
bolts are located at the center of each of the 3
rocker housing support bridges.
(c) Install and tighten 2±piece mounting stud to
rocker housing. If removing the #6 fuel injector,
separate the 2±piece mounting stud. Install lower
half of mounting stud to center of rocker housing
bridge. Install upper half of mounting stud to lower
half.(d) Position tool handle to mounting stud and
install handle nut. Leave handle nut loose to allow
a pivoting action.
(e) Position lower part of clamshell halves to
sides of fuel injector (wider shoulder to bottom).
The upper part of clamshell halves should also be
positioned into machined shoulder on the handles
pivoting head.
(f) Slide the retainer sleeve over pivoting handle
head to lock clamshell halves together.
(g) Be sure handle pivot nut is loose.
(h) Depress handle downward to remove fuel
injector straight up from cylinder head bore.
(11) Remove and discard injector sealing washer.
This should be located on tip of injector (Fig. 20) or
(Fig. 21).
INSTALLATION
(1) Inspect fuel injector.
(a) Look for burrs on injector inlet.
(b) Check nozzle holes for hole erosion or plug-
ging.
(c) Inspect end of nozzle for burrs or rough
machine marks.
(d) Look for cracks at nozzle end.
(e)
Check nozzle color for signs of overheating.
Overheating will cause nozzle to turn a dark yellow/
tan or blue (depending on overheating temperature).
(f)If any of these conditions occur, replace injector.
(2)Thoroughly clean fuel injector cylinder head
bore with special Cummins wire brush tool or equiva-
lent (Fig. 22). Blow out bore hole with compressed air.
Fig. 16 CONNECTOR TUBE REMOVAL
1 - CONNECTOR TUBE
2 - TOOL #9015
3 - CYLINDER HEAD (LEFT SIDE)
DRFUEL INJECTION - DIESEL 14 - 87
FUEL INJECTOR (Continued)

DIAGNOSIS AND TESTING
LOW LUBRICANT LEVEL
A low transmission lubricant level is generally the
result of a leak, inadequate lubricant fill or an incor-
rect lubricant level check. Leaks can occur at the
mating surfaces of the gear case, adaptor or exten-
sion housing, or from the front/rear seals. A sus-
pected leak could also be the result of an overfill
condition.
Leaks at the rear of the extension or adapter hous-
ing will be from the housing oil seals. Leaks at com-
ponent mating surfaces will probably be the result of
inadequate sealer, gaps in the sealer, incorrect bolt
tightening or use of a non-recommended sealer.
A leak at the front of the transmission will be from
either the front bearing retainer or retainer seal.
Lubricant may be seen dripping from the clutch
housing after extended operation. If the leak is
severe, it may also contaminate the clutch disc caus-
ing the disc to slip, grab and or chatter.
A correct lubricant level check can only be made
when the vehicle is level. Also allow the lubricant to
settle for a minute or so before checking. These rec-
ommendations will ensure an accurate check and
avoid an underfill or overfill condition. Always check
the lubricant level after any addition of fluid to avoid
an incorrect lubricant level condition.
HARD SHIFTING
Hard shifting is usually caused by a low lubricant
level, improper or contaminated lubricants. The con-
sequence of using non-recommended lubricants is
noise, excessive wear, internal bind and hard shift-
ing. Substantial lubricant leaks can result in gear,
shift rail, synchro, and bearing damage. If a leak
goes undetected for an extended period, the first indi-
cations of component damage are usually hard shift-
ing and noise.
Shift component damage or damaged clutch pres-
sure plate or disc are additional probable causes of
increased shift effort. Worn/damaged pressure plate
or disc can cause incorrect release. If clutch problem
is advanced, gear clash during shifts can result.
Worn or damaged synchro rings can cause gear clash
when shifting into any forward gear. In some new or
rebuilt transmissions, new synchro rings may tend to
stick slightly causing hard or noisy shifts. In most
cases this condition will decline as the rings wear-in.
TRANSMISSION NOISE
Most manual transmissions make some noise dur-
ing normal operation. Rotating gears generate a mild
whine that is audible, but generally only at extreme
speeds.Severe highly audible transmission noise is gener-
ally the initial indicator of a lubricant problem.
Insufficient, improper or contaminated lubricant will
promote rapid wear of gears, synchros, shift rails,
forks and bearings. The overheating caused by a
lubricant problem, can also lead to gear and bearing
damage.
REMOVAL
(1) Disconnect battery negative cable.
(2) Shift transmission into Neutral.
(3) Remove shift boot bezel screws and slide boot
upward on shift lever extension.
(4) Remove shift lever extension from the shift
tower and lever assembly.
(5) Raise vehicle on hoist.
(6) Remove skid plate, if equipped.
(7) Drain lubricant if transmission will be disas-
sembled for service.
(8) Mark propeller shaft/shafts and companion
flange yoke/yokes for installation reference and
remove propeller shaft/shafts.
(9) Disconnect harness from clips on transmission
housing.
(10) Remove transfer case linkage if equipped.
(11) Remove transfer case mounting nuts and
remove transfer case if equipped.
(12) Remove slave cylinder mounting nut and
remove cylinder (Fig. 2).
Fig. 2 SLAVE CYLINDER
1 - MOUNTING NUTS
2 - SLAVE CYLINDER
DRMANUAL TRANSMISSION - NV3500 21 - 3
MANUAL TRANSMISSION - NV3500 (Continued)