1998 DODGE RAM 1500 mileage

DESCRIPTION SPECIFICATION
REAR AXLE   .03 L (1 oz)
9 1/4 2.32 L (4.9 pts.)***
10 1/2 AA 2.25 L (4.75 pts.)
11 1/2 AA 3.62 L (7.65 pts)
*** With Trac-Lok add 118 ml (4 oz.) of Limited Slip
Additive.
** Includes 0.9L (1.0 qts.) for coolant reservoir.
*Nominal refill capacities are shown. A variation may
be observed from vehicle to vehicle due to
manufacturing tolerance and refill procedure.
MAINTENANCE SCHEDULES
DESCRIPTION
DESCRIPTION
Maintenance Schedule Information not included in
this section, is located in the appropriate Owner's
Manual.
There are two maintenance schedules that show
therequiredservice for your vehicle.
First is ScheduleªBº. It is for vehicles that are
operated under the conditions that are listed below
and at the beginning of the schedule.
²Day or night temperatures are below 0É C (32É
F).
²Stop and go driving.
²Extensive engine idling.
²Driving in dusty conditions.
²Short trips of less than 16 km (10 miles).
²More than 50% of your driving is at sustained
high speeds during hot weather, above 32É C (90É F).
²Trailer towing.
²Taxi, police, or delivery service (commercial ser-
vice).
²Off-road or desert operation.
²If equipped for and operating with E-85
(ethanol) fuel.
NOTE: If ANY of these apply to the vehicle then
change the engine oil every 3,000 miles (5 000 km)
or 3 months, whichever comes first and follow
schedule ªBº of the(Maintenance Schedules(sec-
tion of this manual.
NOTE: Most vehicles are operated under the condi-
tions listed for Schedule(B(.
Second is ScheduleªAº. It is for vehicles that are
not operated under any of the conditions listed under
Schedule9B9.Use the schedule that best describes the driving
conditions. Where time and mileage are listed, follow
the interval that occurs first.
CAUTION: Failure to perform the required mainte-
nance items may result in damage to the vehicle.
At Each Stop for Fuel
²Check the engine oil level about 5 minutes after
a fully warmed engine is shut off. Checking the oil
level while the vehicle is on level ground will
improve the accuracy of the oil level reading. Add oil
only when the level is at or below the ADD or MIN
mark.
²Check the windshield washer solvent and add if
required.
Once a Month
²Check tire pressure and look for unusual wear
or damage.
²Inspect the battery and clean and tighten the
terminals as required.
²Check the fluid levels of coolant reservoir, brake
master cylinder, power steering and transmission
and add as needed.
²Check all lights and all other electrical items for
correct operation.
At Each Oil Change
²Change the engine oil filter.
²Inspect the exhaust system.
²Inspect the brake hoses.
²Inspect the CV joints (if equipped) and front sus-
pension components.
²Check the automatic transmission fluid level.
²Check the manual transmission fluid level.
²Check the coolant level, hoses, and clamps.
²Rotate the tires at each oil change interval
shown on Schedule ªAº 10 000 km (6,000 miles) or
every other interval shown on Schedule ªBº 10 000
km (6,000 miles).
Tire Rotation
²Rotate the tires at 6,000 miles (10 000 km).
Schedule ªBº
Follow schedule ªBº if you usually operate your
vehicle under one or more of the following conditions.
²Day or night temperatures are below 0É C (32É
F).
²Stop and go driving.
²Extensive engine idling.
²Driving in dusty conditions.
²Short trips of less than 16 km (10 miles).
²More than 50% of your driving is at sustained
high speeds during hot weather, above 32É C (90É F).
0 - 6 LUBRICATION & MAINTENANCEDR
FLUID CAPACITIES (Continued)

Miles 36,000 42,000 48,000 54,000 60,000 66,000
(Kilometers) (58 000) (67 000) (77 000) (84 000) (96 000) (106 000)
[Months] [36] [42] [48] [54] [60] [66]
Change engine oil and engine
oil filter.XXXXX
X
Check transfer case fluid level
(4X4).X
Lubricate outer tie rod ends
2500/3500 (4X4) models only.XXXXX X
Flush and replace engine
coolant at 60 months,
regardless of mileage.X
Inspect brake linings. X X
Replace engine air cleaner
filter.X
Replace spark plugs.X
Inspect PCV valve, replace
as necessary.X*
Replace ignition cables.X
Miles 72,000 78,000 84,000 90,000 96,000 100,000
(Kilometers) (115000) (125 000) (134 000) (144 000) (154 000) 160 000
[Months] [72] [78] [84] [90] [96]
Change engine oil and engine
oil filter.XXXXX
Lubricate outer tie rod ends
2500/3500 (4X4) models only.XXXXX
Check transfer case fluid level
(4X4).X
Flush and replace Power
Steering Fluid.X
Inspect brake linings. X X
Replace engine air cleaner
filter.X
Replace spark plugs.X
Inspect PCV valve, replace
as necessary.X*
Inspect auto tension drive belt
and replace if required
(3.7L/4.7L/5.7L).X
Drain and refill automatic
tranmission fluid and change
main sump filter and spin-on
cooler return filter (if
equipped) [45RFE/545RFE
only].X
DRLUBRICATION & MAINTENANCE 0 - 11
MAINTENANCE SCHEDULES (Continued)

Miles 102,000 108,000 114,000 120,000
(Kilometers) (163 000) (173 000) (182 000) (192 000)
[Months] [102] [108] [114] [120]
Change engine oil and engine oil filter. X X X X
Drain and refill transfer case fluid (4X4). X
Flush and replace engine coolant, if not done at 60 mos. X
Lubricate outer tie rod ends 2500/3500 (4X4) models
only.XXX X
Inspect brake linings. X
Inspect auto tension drive belt and replace if required
(3.7L/4.7L/5.7L).X³X³
Replace ignition cables.X
Replace engine air cleaner filter.X
Replace spark plugs.X
Inspect PCV Valve, replace as necessary X*
* This maintenance is recommended by the manu-
facture to the owner but is not required to maintain
the emissions warranty.
³ This maintenance is not required if previously
replaced.
Inspection and service should also be performed
anytime a malfunction is observed or suspected.
WARNING: You can be badly injured working on or
around a motor vehicle. Do only that service work
for which you have the knowledge and the right
equipment. If you have any doubt about your ability
to perform a service job, take your vehicle to a
competent mechanic.
MAINTENANCE SCHEDULES Ð 24±VALVE
CUMMINS TURBO DIESEL
There are two maintenance schedules that show
therequiredservice for your vehicle.
First is ScheduleªBº. It is for vehicles that are
operated under the conditions that are listed below
and at the beginning of the schedule.
²Day or night temperatures are below 0É C (32É
F).
²Stop and go driving.
²Extensive engine idling.
²Driving in dusty conditions.
²Short trips of less than 16 km (10 miles).
²More than 50% of your driving is at sustained
high speeds during hot weather, above 32É C (90É F).²Trailer towing.
²Taxi, police, or delivery service (commercial ser-
vice).
²Off-road or desert operation.
NOTE: Most vehicles are operated under the condi-
tions listed for Schedule(B(.
Second is ScheduleªAº. It is for vehicles that are
not operated under any of the conditions listed under
Schedule9B9.
Use the schedule that best describes your driving
conditions. Where time and mileage are listed, follow
the interval that occurs first.
CAUTION: Failure to perform the required mainte-
nance items may result in damage to the vehicle.At Each Stop for Fuel
²Check the engine oil level about 15 minutes
after a fully warmed engine is shut off. Checking the
oil level while the vehicle is on level ground will
improve the accuracy of the oil level reading. Add oil
only when the level is at or below the ADD or MIN
mark.
²Check the windshield washer solvent and add if
required.
²Drain water from the fuel filter.
0 - 12 LUBRICATION & MAINTENANCEDR
MAINTENANCE SCHEDULES (Continued)

²LTier 1 EPA (250 hp or 305 hp) Engines Only
(see engine data label for your engine type)
²² California LEV (235 hp) Engines Only (see
engine data label for your engine type)Inspection and service should also be performed
anytime a malfunction is observed or suspected.
Schedule ªAº
Miles 7,500 15,000 22,500 30,000 37,500
(Kilometers) (12 000) (24 000) (36 000) (48 000) (60 000)
[Months] [6] [12] [18] [24] [30]
Change engine oil and engine oil filter. X² XL²X²XL²X²
Lubricate outer tie rod ends 2500/3500
(4X4) models only.XXXX X
Check transfer case fluid level (4X4). X
Inspect water pump weep hole for blockage X X
Replace fuel filter element. Clean the water
in fuel sensor.XX
Inspect drive belts, replace as necessary. X
Inspect brake linings. X
Inspect and adjust parking brake if
necessary.X
Inspect fan hub.X
Inspect damper.X
Inspect front wheel bearings. X
Miles 45,000 52,500 60,000 67,500 75,000
(Kilometers) (72 000) (84 000) (96 000) (108 000) (120 000)
[Months] [36] [42] [48] [54] [60]
Change engine oil and engine oil filter. XL²X²XL²X² XL²
Lubricate outer tie rod ends 2500/3500
(4X4) models only.XXXX X
Check transfer case fluid level. X
Flush and replace engine coolant at 60
months, regardless of mileage.X
Inspect drive belts, replace as necessary. X X
Inspect water pump weep hole for blockage X X X
Replace fuel filter element. Clean the water
in fuel sensor.XX
Inspect brake linings. X X
Inspect and adjust parking brake if
necessary.XX
Inspect fan hub. X
Inspect damper. X
Inspect front wheel bearings. X
Replace fuel filter element. Clean the water
in fuel sensorX
DRLUBRICATION & MAINTENANCE 0 - 17
MAINTENANCE SCHEDULES (Continued)

REMOVAL
USE THE DRB SCAN TOOL TO REPROGRAM
THE NEW POWERTRAIN CONTROL MODULE
(PCM) WITH THE VEHICLES ORIGINAL IDEN-
TIFICATION NUMBER (VIN) AND THE VEHI-
CLES ORIGINAL MILEAGE. IF THIS STEP IS
NOT DONE, A DIAGNOSTIC TROUBLE CODE
(DTC) MAY BE SET.
The PCM is located in the engine compartment
attached to the dash panel (Fig. 5).
To avoid possible voltage spike damage to the
PCM, ignition key must be off, and negative battery
cable must be disconnected before unplugging PCM
connectors.
(1) Disconnect negative battery cable at battery.
(2) Remove cover over electrical connectors. Cover
snaps onto PCM.
(3) Carefully unplug the three 32±way connectors
(four 38±way connectors if equipped with NGC) from
PCM (Fig. 6).
(4) Remove three PCM mounting bolts (Fig. 6) and
remove PCM from vehicle.
INSTALLATION
USE THE DRB SCAN TOOL TO REPROGRAM
THE NEW POWERTRAIN CONTROL MODULE
(PCM) WITH THE VEHICLES ORIGINAL IDEN-
TIFICATION NUMBER (VIN) AND THE VEHI-
CLES ORIGINAL MILEAGE. IF THIS STEP ISNOT DONE, A DIAGNOSTIC TROUBLE CODE
(DTC) MAY BE SET.
(1) Install PCM and 3 mounting bolts to vehicle.
(2) Tighten bolts. Refer to torque specifications.
(3) Check pin connectors in the PCM and the three
32±way connectors (four 38±way connectors if
equipped with NGC) for corrosion or damage. Also,
the pin heights in connectors should all be same.
Repair as necessary before installing connectors.
(4) Install three 32±way connectors (four 38±way
connectors if equipped with NGC).
(5) Install cover over electrical connectors. Cover
snaps onto PCM.
(6) Install negative battery cable.
(7)The 5.7L V-8 engine is equipped with a
fully electronic accelerator pedal position sen-
sor. If equipped with a 5.7L, also perform the
following 3 steps:
(a) Connect negative battery cable to battery.
(b) Turn ignition switch ON, but do not crank
engine.
(c) Leave ignition switch ON for a minimum of
10 seconds. This will allow PCM to learn electrical
parameters.
(d) The DRB IIItScan Tool may also be used to
learn electrical parameters. Go to the Miscella-
neous menu, and then select ETC Learn.
Fig. 5 PCM LOCATION
1 - COWL GRILL
2 - PCM
3 - COWL (RIGHT-REAR)
Fig. 6 PCM REMOVAL / INSTALLATION
1 - THREE 32-WAY CONNECTORS WITH JTEC (FOUR 38-WAY
CONNECTORS WITH NGC)
2 - PCM MOUNTING BRACKET
3 - PCM
4 - PCM MOUNTING SCREWS (3)
8E - 12 ELECTRONIC CONTROL MODULESDR
POWERTRAIN CONTROL MODULE (Continued)

(8) If the previous step is not performed, a Diag-
nostic Trouble Code (DTC) will be set.
(9) If necessary, use DRB IIItScan Tool to erase
any Diagnostic Trouble Codes (DTC's) from PCM.
Also use the DRB scan tool to reprogram new PCM
with vehicles original Vehicle Identification Number
(VIN) and original vehicle mileage.
SENTRY KEY IMMOBILIZER
MODULE
DESCRIPTION
The Sentry Key Immobilizer Module (SKIM) con-
tains a Radio Frequency (RF) transceiver and a cen-
tral processing unit, which includes the Sentry Key
Immobilizer System (SKIS) program logic. The SKIS
programming enables the SKIM to program and
retain in memory the codes of at least two, but no
more than eight electronically coded Sentry Key
transponders. The SKIS programming also enables
the SKIM to communicate over the Programmable
Communication Interface (PCI) bus network with the
Powertrain Control Module (PCM) or Electronic Con-
trol Module (ECM), depending on engine application,
and/or the DRBIIItscan tool.
OPERATION
The SKIM transmits and receives RF signals
through a tuned antenna enclosed within a molded
plastic ring that is integral to the SKIM housing.
When the SKIM is properly installed on the steering
column, the antenna ring is oriented around the igni-
tion lock cylinder housing. This antenna ring must be
located within eight millimeters (0.31 inches) of the
Sentry Key in order to ensure proper RF communica-
tion between the SKIM and the Sentry Key tran-
sponder.
For added system security, each SKIM is pro-
grammed with a unique ªSecret Keyº code and a
security code. The SKIM keeps the ªSecret Keyº code
in memory. The SKIM also sends the ªSecret Keyº
code to each of the programmed Sentry Key tran-
sponders. The security code is used by the assembly
plant to access the SKIS for initialization, or by the
dealer technician to access the system for service.
The SKIM also stores in its memory the Vehicle
Identification Number (VIN), which it learns through
a PCI bus message from the PCM (NGC) or ECM
(Cummins) during initialization.The SKIM and the PCM/ECM both use software
that includes a rolling code algorithm strategy, which
helps to reduce the possibility of unauthorized SKIS
disarming. The rolling code algorithm ensures secu-
rity by preventing an override of the SKIS through
the unauthorized substitution of the SKIM or the
PCM/ECM. However, the use of this strategy also
means that replacement of either the SKIM or the
PCM/ECM units will require a system initialization
procedure to restore system operation.
When the ignition switch is turned to the ON or
START positions, the SKIM transmits an RF signal
to excite the Sentry Key transponder. The SKIM then
listens for a return RF signal from the transponder
of the Sentry Key that is inserted in the ignition lock
cylinder. If the SKIM receives an RF signal with
valid ªSecret Keyº and transponder identification
codes, the SKIM sends a ªvalid keyº message to the
PCM/ECM over the PCI bus. If the SKIM receives an
invalid RF signal or no response, it sends ªinvalid
keyº messages to the PCM/ECM. The PCM/ECM will
enable or disable engine operation based upon the
status of the SKIM messages.
The SKIM also sends messages to the Instrument
Cluster which controls the VTSS indicator LED. The
SKIM sends messages to the Instrument Cluster to
turn the LED on for about three seconds when the
ignition switch is turned to the ON position as a bulb
test. After completion of the bulb test, the SKIM
sends bus messages to keep the LED off for a dura-
tion of about one second. Then the SKIM sends mes-
sages to turn the LED on or off based upon the
results of the SKIS self-tests. If the VTSS indicator
LED comes on and stays on after the bulb test, it
indicates that the SKIM has detected a system mal-
function and/or that the SKIS has become inopera-
tive.
If the SKIM detects an invalid key when the igni-
tion switch is turned to the ON position, it sends
messages to flash the VTSS indicator LED. The
SKIM can also send messages to flash the LED as an
indication to the customer that the SKIS has been
placed in it's ªCustomer Learnº programming mode.
See Sentry Key Immobilizer System Transponder
Programming in this section for more information on
the ªCustomer Learnº programming mode.
For diagnosis or initialization of the SKIM and the
PCM/ECM, a DRBIIItscan tool and the proper Pow-
ertrain Diagnostic Procedures manual are required.
The SKIM cannot be repaired and, if faulty or dam-
aged, the unit must be replaced.
DRELECTRONIC CONTROL MODULES 8E - 13
POWERTRAIN CONTROL MODULE (Continued)

SPARK PLUG
DESCRIPTION
Resistor type spark plugs are used on all engines.
Sixteen spark plugs (2 per cylinder) are used with
5.7L V-8 engines.
DIAGNOSIS AND TESTING - SPARK PLUG
CONDITIONS
To prevent possible pre-ignition and/or mechanical
engine damage, the correct type/heat range/number
spark plug must be used.
Always use the recommended torque when tighten-
ing spark plugs. Incorrect torque can distort the
spark plug and change plug gap. It can also pull the
plug threads and do possible damage to both the
spark plug and the cylinder head.
Remove the spark plugs and examine them for
burned electrodes and fouled, cracked or broken por-
celain insulators. Keep plugs arranged in the order
in which they were removed from the engine. A sin-
gle plug displaying an abnormal condition indicates
that a problem exists in the corresponding cylinder.
Replace spark plugs at the intervals recommended in
the Lubrication and Maintenance section.
Spark plugs that have low mileage may be cleaned
and reused if not otherwise defective, carbon or oil
fouled.
CAUTION: Never use a motorized wire wheel brush
to clean the spark plugs. Metallic deposits will
remain on the spark plug insulator and will cause
plug misfire.
Spark plug resistance values range from 6,000 to
20,000 ohms (when checked with at least a 1000 volt
spark plug tester).Do not use an ohmmeter to
check the resistance values of the spark plugs.
Inaccurate readings will result.
NORMAL OPERATING
The few deposits present on the spark plug will
probably be light tan or slightly gray in color. This is
evident with most grades of commercial gasoline
(Fig. 23). There will not be evidence of electrode
burning. Gap growth will not average more than
approximately 0.025 mm (.001 in) per 3200 km (2000
miles) of operation. Spark plugs that have normal
wear can usually be cleaned, have the electrodes
filed, have the gap set and then be installed.Some fuel refiners in several areas of the United
States have introduced a manganese additive (MMT)
for unleaded fuel. During combustion, fuel with MMT
causes the entire tip of the spark plug to be coated
with a rust colored deposit. This rust color can be
misdiagnosed as being caused by coolant in the com-
bustion chamber. Spark plug performance may be
affected by MMT deposits.
COLD FOULING/CARBON FOULING
Cold fouling is sometimes referred to as carbon
fouling. The deposits that cause cold fouling are basi-
cally carbon (Fig. 23). A dry, black deposit on one or
two plugs in a set may be caused by sticking valves
or defective spark plug cables. Cold (carbon) fouling
of the entire set of spark plugs may be caused by a
clogged air cleaner element or repeated short operat-
ing times (short trips).
WET FOULING OR GAS FOULING
A spark plug coated with excessive wet fuel or oil
is wet fouled. In older engines, worn piston rings,
leaking valve guide seals or excessive cylinder wear
can cause wet fouling. In new or recently overhauled
engines, wet fouling may occur before break-in (nor-
mal oil control) is achieved. This condition can usu-
ally be resolved by cleaning and reinstalling the
fouled plugs.
OIL OR ASH ENCRUSTED
If one or more spark plugs are oil or oil ash
encrusted (Fig. 24), evaluate engine condition for the
cause of oil entry into that particular combustion
chamber.
Fig. 23 NORMAL OPERATION AND COLD (CARBON)
FOULING
1 - NORMAL
2 - DRY BLACK DEPOSITS
3 - COLD (CARBON) FOULING
DRIGNITION CONTROL 8I - 17

CRANKCASE OIL LEVEL INSPECTION
CAUTION: Do not overfill crankcase with engine oil,
pressure loss or oil foaming can result.
Inspect engine oil level approximately every 800
kilometers (500 miles). Unless the engine has exhib-
ited loss of oil pressure, run the engine for about five
minutes before checking oil level. Checking engine oil
level on a cold engine is not accurate.
To ensure proper lubrication of an engine, the
engine oil must be maintained at an acceptable level.
The acceptable levels are indicated between the ADD
and SAFE marks on the engine oil dipstick.
(1) Position vehicle on level surface.
(2) With engine OFF, allow approximately ten min-
utes for oil to settle to bottom of crankcase, remove
engine oil dipstick.
(3) Wipe dipstick clean.
(4) Install dipstick and verify it is seated in the
tube.
(5) Remove dipstick, with handle held above the
tip, take oil level reading.
(6) Add oil only if level is below the ADD mark on
dipstick.
ENGINE OIL CHANGE
Change engine oil at mileage and time intervals
described in Maintenance Schedules.
Run engine until achieving normal operating tem-
perature.
(1) Position the vehicle on a level surface and turn
engine off.
(2) Hoist and support vehicle on safety stands.
(3) Remove oil fill cap.
(4) Place a suitable drain pan under crankcase
drain.
(5) Remove drain plug from crankcase and allow
oil to drain into pan. Inspect drain plug threads for
stretching or other damage. Replace drain plug if
damaged.
(6) Install drain plug in crankcase.
(7) Lower vehicle and fill crankcase with specified
type and amount of engine oil described in this sec-
tion.
(8) Install oil fill cap.
(9) Start engine and inspect for leaks.
(10) Stop engine and inspect oil level.
USED ENGINE OIL DISPOSAL
Care should be exercised when disposing used
engine oil after it has been drained from a vehicle
engine. Refer to the WARNING at beginning of this
section.
INTAKE MANIFOLD
DESCRIPTION
The intake manifold (Fig. 88) is made of a compos-
ite material and features 300 mm (11.811 in.) long
runners which maximizes low end torque. The intake
manifold uses single plane sealing which consist of
six individual press in place port gaskets to prevent
leaks. The throttle body attaches directly to the
intake manifold. Eight studs and two bolts are used
to fasten the intake to the head.
DIAGNOSIS AND TESTING - INTAKE
MANIFOLD LEAKS
An intake manifold air leak is characterized by
lower than normal manifold vacuum. Also, one or
more cylinders may not be functioning.
WARNING: USE EXTREME CAUTION WHEN THE
ENGINE IS OPERATING. DO NOT STAND IN A
DIRECT LINE WITH THE FAN. DO NOT PUT YOUR
HANDS NEAR THE PULLEYS, BELTS OR THE FAN.
DO NOT WEAR LOOSE CLOTHING.
Fig. 88 Intake Manifold
1 - THROTTLE BODY
2 - INTAKE MANIFOLD
3 - INTAKE PORT GASKETS
9 - 72 ENGINE - 3.7LDR
OIL (Continued)