1998 DODGE RAM 1500 Tow capacity

INSTALLATION
(1) Clean the housing cavity with a flushing oil,
light engine oil or lint free cloth.
CAUTION: Do not use water, steam, kerosene or
gasoline for cleaning.
(2) Lubricate differential case bearing.
(3) Install differential case with bearings cups into
the housing.
NOTE: A light coat of grease on the cups will hold
them in place during installation.
(4) Install bearing caps and bolts (Fig. 36). Tighten
the bearing cap bolts finger-tight.
NOTE: Do not torque bearing cap and bolts at this
time.
(5) Slide differential case toward the pinion gear
until the gears make contact/zero backlash. If zero
backlash cannot be obtained, turn the pinion side
adjuster until zero backlash is obtained.
(6) Holding the differential case toward the pinion
gear, turn bearing adjusters with Spanner Wrench
8883 until they make contact with the differential
bearings/cups.
(7) Back off the ring gear side adjuster 4 holes, to
obtain initial ring gear backlash.
(8) Install ring gear side adjuster lock and bolt. Do
not tighten adjuster lock bolt at this time.(9) Tighten pinion gear side adjuster firmly
against the differential case bearing cup.
(10) Rotate the pinion several times to seat the dif-
ferential bearings.
(11) Loosen pinion gear side adjuster until it is no
longer in contact with the bearing cup.
(12) Tighten pinion gear side adjuster until it just
makes contact with the bearing cup.
(13) Tighten pinion gear side adjuster an addi-
tional:
²New Bearings6 Adjuster Holes
²Original Bearings4 Adjuster Holes
(14) Install pinion gear side adjuster lock and bolt.
Do not tighten adjuster lock bolt at this time.
(15) Tighten bearing cap bolts to 165 N´m (122 ft.
lbs.).
(16) Tighten adjuster lock bolts to 25 N´m (18 ft.
lbs.) (Fig. 37).
(17) Measure ring gear backlash and check gear
tooth contact pattern. Refer to Adjustments for pro-
cedure.
(18) Install axle shafts.
(19) Install differential housing gasket and cover.
Tighten cover bolts to 40 N´m (30 ft. lbs.).
(20) Fill axle with lubricant, refer to Lubrication &
Maintenance for capacity and lubricant type.
(21) Install fill plug and tighten to 32 N´m (24 ft.
lbs.).
Fig. 36 CASE BEARING CAP
1 - DIFFERENTIAL HOUSING
2 - BEARING CAP
3 - ADJUSTERFig. 37 ADJUSTER LOCK BOLT
1 - DIFFERENTIAL CASE
2 - ADJUSTER LOCK
3 - ADJUSTER LOCK BOLT
4 - BEARING CAP BOLT
3 - 130 REAR AXLE - 10 1/2 AADR
DIFFERENTIAL (Continued)

(5) Slide differential case toward the pinion gear
until the gears make contact/zero backlash. If zero
backlash cannot be obtained, turn the pinion side
adjuster until zero backlash is obtained.
(6) Holding the differential case toward the pinion
gear, turn bearing adjusters with Spanner Wrench
8883 until they make contact with the differential
bearings/cups.
(7) Back off the ring gear side adjuster 4 holes, to
obtain initial ring gear backlash.
(8) Install ring gear side adjuster lock and bolt. Do
not tighten adjuster lock bolt at this time.
(9) Tighten pinion gear side adjuster firmly
against the differential case bearing cup.
(10) Rotate the pinion several times to seat the dif-
ferential bearings.
(11) Loosen pinion gear side adjuster until it is no
longer in contact with the bearing cup.
(12) Tighten pinion gear side adjuster until it just
makes contact with the bearing cup.
(13) Tighten pinion gear side adjuster an addi-
tional:
²New Bearings6 Adjuster Holes
²Original Bearings4 Adjuster Holes
(14) Install pinion gear side adjuster lock and bolt.
Do not tighten adjuster lock bolt at this time.
(15) Tighten bearing cap bolts to 281 N´m (207 ft.
lbs.).
(16) Tighten adjuster lock bolts to 25 N´m (18 ft.
lbs.) (Fig. 37).
(17) Measure ring gear backlash and check gear
tooth contact pattern. Refer to Adjustments for pro-
cedure.
(18) Install axle shaft gasket and install axle
shafts.
(19) Install differential housing gasket and cover.
Tighten cover bolts to 40 N´m (30 ft. lbs.).
(20) Fill axle with lubricant, refer to Lubrication &
Maintenance for capacity and lubricant type.
(21) Install fill plug and tighten to 32 N´m (24 ft.
lbs.).
DIFFERENTIAL TRAC-RITE
DESCRIPTION
The Trac-RiteŸ differential is a helical gear differ-
ential. The differential has two side gears, six pinion
gears and six pinion brake shoes.
NOTE: The differential is seviced as an assembly
only if damaged, but can be disassembled for
cleaning. The assembly should be cleaned every
time a bearing is changed due to damage.
OPERATION
When one wheel begins to spin the pinion gears on
that side are forced toward the pinion brake shoes.
The pinion brake shoes then cause frictional drag on
the opposite pinion gears and the side gear. These
friction forces transfer the power to the opposite
wheel. Once the frictional forces are overcome, differ-
entiation will occur. The torque will be continually
biased by the frictional forces to the high traction
wheel.
DISASSEMBLY
(1) Remove differential ring gear bolts.
(2) Remove differential case cover locating screws
(Fig. 38).
(3) Remove differential case cover.
(4) Remove side gear and thrust washer (Fig. 39).
NOTE: Mark all component locations.
Fig. 37 ADJUSTER LOCK BOLT
1 - DIFFERENTIAL CASE
2 - ADJUSTER LOCK
3 - ADJUSTER LOCK BOLT
4 - BEARING CAP BOLT
3 - 158 REAR AXLE - 11 1/2 AADR
DIFFERENTIAL (Continued)

COOLING
TABLE OF CONTENTS
page page
COOLING
DESCRIPTION
DESCRIPTION - COOLING SYSTEM FLOW
3.7L/4.7L/5.7L ENGINE..................1
DESCRIPTION - COOLING SYSTEM FLOW -
5.9L DIESEL..........................3
DESCRIPTION - HOSE CLAMPS...........3
OPERATION
OPERATION - COOLING SYSTEM.........5
OPERATION - HOSE CLAMPS............5
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTINGÐON-BOARD
DIAGNOSTICS (OBD)...................5
DIAGNOSIS AND TESTING - COOLING
SYSTEM - TESTING FOR LEAKS..........5
DIAGNOSIS AND TESTING - COOLING
SYSTEM DIESEL ENGINE................7
DIAGNOSIS AND TESTING - PRELIMINARY
CHECKS............................10
STANDARD PROCEDURE
STANDARD PROCEDURE - COOLANT
LEVEL CHECK........................17STANDARD PROCEDURE - COOLING
SYSTEM CLEANING/REVERSE FLUSHING . . 17
STANDARD PROCEDURE - DRAINING
COOLING SYSTEM - ALL GAS ENGINES . . . 17
STANDARD PROCEDURE - REFILLING
COOLING SYSTEM - ALL GAS ENGINES . . . 18
STANDARD PROCEDURE - DRAINING
COOLING SYSTEM 5.9L DIESEL ENGINE . . . 18
STANDARD PROCEDURE - REFILLING
COOLING SYSTEM 5.9L DIESEL ENGINE . . . 19
STANDARD PROCEDURE - ADDING
ADDITIONAL COOLANT.................19
SPECIFICATIONS
TORQUE............................19
SPECIFICATIONS -....................20
SPECIAL TOOLS
COOLING...........................20
ACCESSORY DRIVE......................21
ENGINE...............................30
TRANSMISSION.........................67
COOLING
DESCRIPTION
DESCRIPTION - COOLING SYSTEM FLOW
3.7L/4.7L/5.7L ENGINE
The cooling system regulates engine operating tem-
perature. It allows the engine to reach normal oper-
ating temperature as quickly as possible. It also
maintains normal operating temperature and pre-
vents overheating.The cooling system provides a means of heating
the passenger compartment and cooling the auto-
matic transmission fluid (if equipped). The cooling
system is pressurized and uses a centrifugal water
pump to circulate coolant through the system. The
coolant recovery/reserve system utilizes an ambient
overflow bottle (Fig. 2).
An optional factory installed maximum duty cool-
ing package is available on most models. This pack-
age will provide additional cooling capacity for
vehicles used under extreme conditions such as
trailer towing in high ambient temperatures (Fig. 1).
DRCOOLING 7 - 1

OPERATION
OPERATION - COOLING SYSTEM
The cooling system regulates engine operating tem-
perature. It allows the engine to reach normal oper-
ating temperature as quickly as possible. It also
maintains normal operating temperature and pre-
vents overheating.
The cooling system also provides a means of heat-
ing the passenger compartment and cooling the auto-
matic transmission fluid (if equipped). The cooling
system is pressurized and uses a centrifugal water
pump to circulate coolant throughout the system.
All engines utilize an ambient overflow bottle for
coolant recovery/reserve.
An optional factory installed maximum duty cool-
ing package is available on most models. This pack-
age will provide additional cooling capacity for
vehicles used under extreme conditions such as
trailer towing in high ambient temperatures.
OPERATION - HOSE CLAMPS
The spring type hose clamp applies constant ten-
sion on a hose connection. To remove a spring type
hose clamp, only use constant tension clamp pliers
designed to compress the hose clamp.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTINGÐON-BOARD
DIAGNOSTICS (OBD)
COOLING SYSTEM RELATED DIAGNOSTICS
The Engine Control Module (ECM) has been pro-
grammed to monitor certain cooling system compo-
nents:
²If the engine has remained cool for too long a
period, such as with a stuck open thermostat, a Diag-
nostic Trouble Code (DTC) can be set.
²If an open or shorted condition has developed in
the electronically controlled viscous fan clutch circuit,
a Diagnostic Trouble Code (DTC) can be set.
²If fan speed is not detected a DTC will be set.
²Coolant temperature sensor circuit problems can
set a DTC.
If the problem is sensed in a monitored circuit
often enough to indicated an actual problem, a DTC
is stored. The DTC will be stored in the ECM mem-
ory for eventual display to the service technician.
(Refer to 25 - EMISSIONS CONTROL - DESCRIP-
TION).
ACCESSING DIAGNOSTIC TROUBLE CODES
To read DTC's and to obtain cooling system data,
(Refer to 25 - EMISSIONS CONTROL - DESCRIP-
TION).
ERASING TROUBLE CODES
After the problem has been repaired, use the
DRBIIItscan tool to erase a DTC. Refer to the
appropriate Powertrain Diagnostic Procedures ser-
vice information for operation of the DRBIIItscan
tool.
DIAGNOSIS AND TESTING - COOLING SYSTEM
- TESTING FOR LEAKS
ULTRAVIOLET LIGHT METHOD
A leak detection additive is available through the
parts department that can be added to cooling sys-
tem. The additive is highly visible under ultraviolet
light (black light). Pour one ounce of additive into
cooling system. Place heater control unit in HEAT
position. Start and operate the engine until the radi-
ator upper hose is warm to the touch. Aim the com-
mercially available black light tool at the components
to be checked. If leaks are present, the black light
will cause the additive to glow a bright green color.
The black light can be used in conjunction with a
pressure tester to determine if any external leaks
exist (Fig. 5).
Fig. 4 Spring Clamp Size Location
1 - SPRING CLAMP SIZE LOCATION
DRCOOLING 7 - 5
COOLING (Continued)