
(3) Insert oil pickup tube in oil pump and position
pump in rear case (Fig. 86).(4) Apply bead of MopartGasket Maker, or equiv-
alent, to mating surface of front case. Keep sealer
bead width to maximum of 3/16 inch. Do not use
excessive amount of sealer as excess will be displaced
into case interior.
(5) Align oil pump with mainshaft and align shift
rail with bore in rear case. Then install rear case and
oil pump assembly (Fig. 87). Be sure oil pump and
pickup tube remain in position during case installa-
tion.
(6) Install 4-5 rear case-to front case bolts to hold
rear case in position. Tighten bolts snug but not to
specified torque at this time.
CAUTION: Verify that shift rail (Fig. 88), and case
alignment dowels are seated before installing any
bolts. Case could be cracked if shaft rail or dowels
are misaligned.
(7) Verify that oil pump is aligned and seated on
rear case. Reposition pump if necessary.
(8) Check stud at end of case halves (Fig. 89). If
stud was loosened or came out during disassembly,
apply LoctiteŸ 242 to stud threads and reseat stud
in case.
(9) Apply LoctiteŸ 242 to remainder of rear case-
to-front case bolt threads and install bolts. Be sure
lock washers are used on studs/bolts at case ends.
Tighten bolts, or stud nuts as follows:
Fig. 83 Case Magnet Installation
1 - MAGNET
2 - CASE POCKET
Fig. 84 Pickup Tube O-Ring Installation
1 - O-RING (PUMP PICKUP)
2 - PICKUP TUBE
Fig. 85 Oil Pickup Tube And Filter Position In Rear
Case
1 - FILTER
2 - TUBE AND HOSE
3 - TUBE IN NOTCH
Fig. 86 Positioning Oil Pump In Rear Case
1 - OIL PUMP
2 - REAR CASE
3 - FILTER
4 - PICKUP TUBE
BR/BETRANSFER CASE - NV241LD 21 - 455
TRANSFER CASE - NV241LD (Continued)

REAR RETAINER AND EXTENSION
(1) Clean mating surfaces of transfer case housing
and the rear retainer of any original gasket material.
(2) Install new rear retainer gasket onto the trans-
fer case housing or rear retainer.
(3) Align and install rear retainer on rear case
(Fig. 92).
(4) Apply MopartSilicone Sealer to threads of rear
retainer bolts. Then install retainer bolts finger tight.
(5) Install output bearing on mainshaft and seat it
in rear retainer with suitable size pipe tool (Fig. 93).(6) Install output bearing retaining ring (Fig. 94).
(7) Tighten rear retainer bolts to 27-34 N´m (20-25
ft. lbs.) torque.
(8) Install new seal in rear extension housing seal
with suitable size installer tool.
(9) Apply bead of MopartGasket Maker, or equiv-
alent, to mating surface of rear extension housing.
Keep sealer bead width to maximum of 3/16 inch. Do
not use excessive amount of sealer as excess could be
displaced into output bearing.
(10) Align and install rear extension on retainer
(Fig. 95).
Fig. 92 Rear Retainer Installation
1 - REAR RETAINER
2 - SHIFT RAIL
Fig. 93 Output Bearing Installation
1 - OUTPUT BEARING
2 - PIPE TOOL
Fig. 94 Output Bearing Retaining Ring Installation
1 - OUTPUT BEARING
2 - RETAINING RING
Fig. 95 Rear Extension Installation
1 - REAR EXTENSION
2 - RETAINER
3 - EXTENSION SEAL
BR/BETRANSFER CASE - NV241LD 21 - 457
TRANSFER CASE - NV241LD (Continued)

(4) Install retaining ring on input gear (Fig. 61).
(5) Apply bead of MopartGasket Maker, or equiv-
alent, to mating surface of input retainer. Keep
sealer bead width to maximum of 3/16 inch. Do not
use excessive amount of sealer as excess could be dis-
placed into oil channel and feed hole in case.
(6) Align oil channel in retainer with oil feed hole
in front case (Fig. 62).
(7) Install retainer on input gear shaft and front
case (Fig. 63).(8) Apply MopartSilicone Sealer to threads of
input retainer bolts. Then install and tighten bolts to
27-34 N´m (20-25 ft. lbs.) torque.
MAINSHAFT
(1) Install drive sprocket on mainshaft (Fig. 64).
Fig. 61 Installing Input Gear Retaining Ring
1 - INPUT BEARING RETAINING RING
2 - SNAP-RING PLIERS
3 - INPUT GEAR
Fig. 62 Aligning Retainer Oil Channel and Case
Feed Holes
1 - FEED HOLE
2 - FRONT CASE
3 - FEED CHANNEL
4 - BEARING RETAINER
Fig. 63 Input Bearing Retainer Installation
1 - FRONT CASE
2 - INPUT BEARING RETAINER
Fig. 64 Drive Sprocket Installation
1 - MAINSHAFT
2 - DRIVE SPROCKET
BR/BETRANSFER CASE - NV241HD 21 - 485
TRANSFER CASE - NV241HD (Continued)

(7) Realign sliding clutch on synchronizer hub if
necessary. Press synchronizer struts inward to ease
realignment. Be sure mainshaft is fully seated before
proceeding.
(8) Install spring and cup on shift rail (Fig. 87).
(9) Insert magnet in front case pocket (Fig. 88).
OIL PUMP AND REAR CASE
Lubricate the oil pump components before installa-
tion. Prime the oil pickup tube by pouring a little oil
into the tube before installation.
(1) Install new o-ring in pickup tube inlet of oil
pump (Fig. 89).
(2) Position oil pickup tube and filter in rear case.
Be sure pickup filter is seated in case pocket and
that pickup tube is aligned in case notches (Fig. 90).
Be sure hose that connects tube to filter is securely
positioned.
(3) Insert oil pickup tube in oil pump and position
pump in rear case (Fig. 91).(4) Apply bead of MopartGasket Maker, or equiv-
alent, to mating surface of front case. Keep sealer
bead width to maximum of 3/16 inch. Do not use
excessive amount of sealer as excess will be displaced
into case interior.
(5) Align oil pump with mainshaft and align shift
rail with bore in rear case. Then install rear case and
oil pump assembly (Fig. 92). Be sure oil pump and
pickup tube remain in position during case installa-
tion.
(6) Install 4-5 rear case-to front case bolts to hold
rear case in position. Tighten bolts snug but not to
specified torque at this time.
CAUTION: Verify that shift rail (Fig. 93), and case
alignment dowels are seated before installing any
bolts. Case could be cracked if shaft rail or dowels
are misaligned.
Fig. 87 Shift Rail Spring And Cup Installation
1 - CUP
2 - SPRING
Fig. 88 Case Magnet Installation
1 - MAGNET
2 - CASE POCKET
Fig. 89 Pickup Tube O-Ring Installation
1 - O-RING (PUMP PICKUP)
2 - PICKUP TUBE
Fig. 90 Oil Pickup Tube And Filter Position In Rear
Case
1 - FILTER
2 - TUBE AND HOSE
3 - TUBE IN NOTCH
21 - 492 TRANSFER CASE - NV241HDBR/BE
TRANSFER CASE - NV241HD (Continued)

COMPANION FLANGE
(1) Install companion flange seal on front shaft
(Fig. 95).
(2) Install companion flange on front shaft (Fig.
96). Then install and tighten flange nut to 176-271
N´m (130-200 ft. lbs.) torque.
EXTENSION HOUSING AND PTO COVER
(1) Apply bead of MopartGasket Maker, or equiv-
alent, to mating surface of extension housing. Keep
sealer bead width to maximum of 3/16 inch. Do not
use excessive amount of sealer as excess could be dis-
placed into oil pump.
(2) Position extension housing over output shaft.
(3) Spread extension housing retaining ring and
seat extension housing on rear case. Verify that the
retaining ring is seated in output shaft rear bearing.
(4) Install retaining ring access cover.
(5) Apply MopartSilicone Sealer, or equivalent, to
threads of extension housing bolts. Then install bolts
finger tight.
(6) Tighten extension housing bolts to 27-34 N´m
(20-25 ft. lbs.) torque.
(7) Apply MopartSilicone Sealer to mating surface
of PTO cover and to cover bolt shanks and underside
of bolt heads. Then install and tighten bolts to 27-34
N´m (20-25 ft. lbs.) torque.
INSTALLATION
(1) Align and seat transfer case on transmission.
Be sure transfer case input gear splines are aligned
with transmission output shaft. Align splines by
rotating transfer case rear output shaft yoke if nec-
essary. Do not install any transfer case attaching
nuts until the transfer case is completely seated
against the transmission.
(2) Install and tighten transfer case attaching
nuts. Tighten nuts to 30-41 N´m (20-30 ft.lbs.).
(3) Install rear crossmember.
(4) Remove jack stand from under transmission.
(5) Align and connect propeller shafts. (Refer to 3 -
DIFFERENTIAL & DRIVELINE/PROPELLER
SHAFT/PROPELLER SHAFT - INSTALLATION)
(6) Connect vacuum harness and vent hose.
(7) Connect shift rod to transfer case lever or floor
shift arm. Use channel lock style pliers to press rod
back into lever grommet.
(8) Adjust shift linkage, if necessary.
(9) Fill transfer case with recommended transmis-
sion fluid and install fill plug.
(10) Install skid plate, if equipped. (Refer to 13 -
FRAMES & BUMPERS/FRAME/TRANSFER CASE
SKID PLATE - INSTALLATION)
(11) Lower vehicle
Fig. 95 Installing Flange Seal On Front Shaft
1 - FRONT OUTPUT SHAFT
2 - FLANGE SEAL
Fig. 96 Installing Companion Flange On Front Shaft
1 - COMPANION FLANGE
21 - 494 TRANSFER CASE - NV241HDBR/BE
TRANSFER CASE - NV241HD (Continued)

DIAGNOSIS AND TESTING
WHEEL INSPECTION
Inspect wheels for:
²Excessive run out
²Dents or cracks
²Damaged wheel lug nut holes
²Air Leaks from any area or surface of the rim
NOTE: Do not attempt to repair a wheel by hammer-
ing, heating or welding.
If a wheel is damaged an original equipment
replacement wheel should be used. When obtaining
replacement wheels, they should be equivalent in
load carrying capacity. The diameter, width, offset,
pilot hole and bolt circle of the wheel should be the
same as the original wheel.
WARNING: FAILURE TO USE EQUIVALENT REPLACE-
MENT WHEELS MAY ADVERSELY AFFECT THE
SAFETY AND HANDLING OF THE VEHICLE. USED
WHEELS ARE NOT RECOMMENDED. THE SERVICE
HISTORY OF THE WHEEL MAY HAVE INCLUDED
SEVERE TREATMENT OR VERY HIGH MILEAGE. THE
RIM COULD FAIL WITHOUT WARNING.
STANDARD PROCEDURE - DUAL REAR WHEEL
INSTALLATION
Dual rear wheels use a special heavy duty lug nut
wrench. It is recommended to remove and install dual
rear wheels only when the proper wrench is available.
The wrench is also use to remove wheel center caps for
more information refer to Owner's Manual.
The tires on both wheels must be completely raised
off the ground when tightening the lug nuts. This
will ensure correct wheel centering and maximum
wheel clamping.
A two piece flat face lug nut with right-hand
threads is used for retaining the wheels on the hubs
(Fig. 20).The dual rear wheel lug nuts should be tightened
according to the following procedure:
²Place two drops of oil to the interface of the nut/
washer (Fig. 20) before installing on the wheel stud.
NOTE: Do not use more then two drops of oil on
the nut/washer, since the center caps attach in this
area.
²Tighten the wheel lug nuts in the numbered
sequential pattern until they are snug tight. Then
tighten lug nut to specified torque following same
number sequence, (Refer to 22 - TIRES/WHEELS/
WHEELS - SPECIFICATIONS).
²Tighten lug nuts in same numbered sequence a
second time to the specified torque. This will ensure
that the wheels are thoroughly mated.
²Check lug nut specified torque after 100 miles
(160 kilometers). Also after 500 miles (800 kilome-
ters) of vehicle operation.
NOTE: Wheel lug nuts should be tightened to spec-
ified torque at every maintenance interval thereafter.
SPECIFICATIONS
TORQUE CHART
TORQUE SPECIFICATIONS
DESCRIPTION N´m Ft. Lbs. In. Lbs.
Lug Nut
BR2500 (8 Stud Wheel)180 135 Ð
Lug Nut
BR3500 (8 Stud Dual
Wheel)195 145 Ð
Fig. 20 Oil Location
1 - PLACE TWO DROPS OF OIL HERE
BR/BETIRES/WHEELS 22 - 11
WHEELS (Continued)

DESCRIPTION - TASK MANAGER
The PCM is responsible for efficiently coordinating
the operation of all the emissions-related compo-
nents. The PCM is also responsible for determining if
the diagnostic systems are operating properly. The
software designed to carry out these responsibilities
is call the 'Task Manager'.
DESCRIPTION - MONITORED SYSTEMS
There are new electronic circuit monitors that
check fuel, emission, engine and ignition perfor-
mance. These monitors use information from various
sensor circuits to indicate the overall operation of the
fuel, engine, ignition and emission systems and thus
the emissions performance of the vehicle.
The fuel, engine, ignition and emission systems
monitors do not indicate a specific component prob-
lem. They do indicate that there is an implied prob-
lem within one of the systems and that a specific
problem must be diagnosed.
If any of these monitors detect a problem affecting
vehicle emissions, the Malfunction Indicator Lamp
(MIL) will be illuminated. These monitors generate
Diagnostic Trouble Codes that can be displayed with
the MIL or a scan tool.
The following is a list of the system monitors:
²Misfire Monitor
²Fuel System Monitor
²Oxygen Sensor Monitor
²Oxygen Sensor Heater Monitor
²Catalyst Monitor
²Leak Detection Pump Monitor (if equipped)
All these system monitors require two consecutive
trips with the malfunction present to set a fault.
Refer to the appropriate Powertrain Diagnos-
tics Procedures manual for diagnostic proce-
dures.
The following is an operation and description of
each system monitor :
OXYGEN SENSOR (O2S) MONITOR
Effective control of exhaust emissions is achieved
by an oxygen feedback system. The most important
element of the feedback system is the O2S. The O2S
is located in the exhaust path. Once it reaches oper-
ating temperature 300É to 350ÉC (572É to 662ÉF), the
sensor generates a voltage that is inversely propor-
tional to the amount of oxygen in the exhaust. The
information obtained by the sensor is used to calcu-
late the fuel injector pulse width. This maintains a
14.7 to 1 Air Fuel (A/F) ratio. At this mixture ratio,
the catalyst works best to remove hydrocarbons (HC),
carbon monoxide (CO) and nitrogen oxide (NOx) from
the exhaust.
The O2S is also the main sensing element for the
Catalyst and Fuel Monitors.The O2S can fail in any or all of the following
manners:
²slow response rate
²reduced output voltage
²dynamic shift
²shorted or open circuits
Response rate is the time required for the sensor to
switch from lean to rich once it is exposed to a richer
than optimum A/F mixture or vice versa. As the sen-
sor starts malfunctioning, it could take longer to
detect the changes in the oxygen content of the
exhaust gas.
The output voltage of the O2S ranges from 0 to 1
volt. A good sensor can easily generate any output
voltage in this range as it is exposed to different con-
centrations of oxygen. To detect a shift in the A/F
mixture (lean or rich), the output voltage has to
change beyond a threshold value. A malfunctioning
sensor could have difficulty changing beyond the
threshold value.
OXYGEN SENSOR HEATER MONITOR
If there is an oxygen sensor (O2S) shorted to voltage
DTC, as well as a O2S heater DTC, the O2S fault
MUST be repaired first. Before checking the O2S fault,
verify that the heater circuit is operating correctly.
Effective control of exhaust emissions is achieved
by an oxygen feedback system. The most important
element of the feedback system is the O2S. The O2S
is located in the exhaust path. Once it reaches oper-
ating temperature 300É to 350ÉC (572 É to 662ÉF), the
sensor generates a voltage that is inversely propor-
tional to the amount of oxygen in the exhaust. The
information obtained by the sensor is used to calcu-
late the fuel injector pulse width. This maintains a
14.7 to 1 Air Fuel (A/F) ratio. At this mixture ratio,
the catalyst works best to remove hydrocarbons (HC),
carbon monoxide (CO) and nitrogen oxide (NOx) from
the exhaust.
The voltage readings taken from the O2S sensor
are very temperature sensitive. The readings are not
accurate below 300ÉC. Heating of the O2S sensor is
done to allow the engine controller to shift to closed
loop control as soon as possible. The heating element
used to heat the O2S sensor must be tested to ensure
that it is heating the sensor properly.
The O2S sensor circuit is monitored for a drop in
voltage. The sensor output is used to test the heater
by isolating the effect of the heater element on the
O2S sensor output voltage from the other effects.
LEAK DETECTION PUMP MONITOR (IF EQUIPPED)
The leak detection assembly incorporates two pri-
mary functions: it must detect a leak in the evapora-
tive system and seal the evaporative system so the
leak detection test can be run.
BR/BEEMISSIONS CONTROL 25 - 17
EMISSIONS CONTROL (Continued)

The primary components within the assembly are:
A three port solenoid that activates both of the func-
tions listed above; a pump which contains a switch,
two check valves and a spring/diaphragm, a canister
vent valve (CVV) seal which contains a spring loaded
vent seal valve.
Immediately after a cold start, between predeter-
mined temperature thresholds limits, the three port
solenoid is briefly energized. This initializes the
pump by drawing air into the pump cavity and also
closes the vent seal. During non test conditions the
vent seal is held open by the pump diaphragm
assembly which pushes it open at the full travel posi-
tion. The vent seal will remain closed while the
pump is cycling due to the reed switch triggering of
the three port solenoid that prevents the diaphragm
assembly from reaching full travel. After the brief
initialization period, the solenoid is de-energized
allowing atmospheric pressure to enter the pump
cavity, thus permitting the spring to drive the dia-
phragm which forces air out of the pump cavity and
into the vent system. When the solenoid is energized
and de energized, the cycle is repeated creating flow
in typical diaphragm pump fashion. The pump is con-
trolled in 2 modes:
Pump Mode: The pump is cycled at a fixed rate to
achieve a rapid pressure build in order to shorten the
overall test length.
Test Mode: The solenoid is energized with a fixed
duration pulse. Subsequent fixed pulses occur when
the diaphragm reaches the Switch closure point.
The spring in the pump is set so that the system
will achieve an equalized pressure of about 7.5º H20.
The cycle rate of pump strokes is quite rapid as the
system begins to pump up to this pressure. As the
pressure increases, the cycle rate starts to drop off. If
there is no leak in the system, the pump would even-
tually stop pumping at the equalized pressure. If
there is a leak, it will continue to pump at a rate rep-
resentative of the flow characteristic of the size of the
leak. From this information we can determine if the
leak is larger than the required detection limit (cur-
rently set at .040º orifice by CARB). If a leak is
revealed during the leak test portion of the test, the
test is terminated at the end of the test mode and no
further system checks will be performed.
After passing the leak detection phase of the test,
system pressure is maintained by turning on the
LDP's solenoid until the purge system is activated.
Purge activation in effect creates a leak. The cycle
rate is again interrogated and when it increases due
to the flow through the purge system, the leak check
portion of the diagnostic is complete.
The canister vent valve will unseal the system
after completion of the test sequence as the pump
diaphragm assembly moves to the full travel position.Evaporative system functionality will be verified by
using the stricter evap purge flow monitor. At an
appropriate warm idle the LDP will be energized to
seal the canister vent. The purge flow will be clocked
up from some small value in an attempt to see a
shift in the 02 control system. If fuel vapor, indicated
by a shift in the 02 control, is present the test is
passed. If not, it is assumed that the purge system is
not functioning in some respect. The LDP is again
turned off and the test is ended.
MISFIRE MONITOR
Excessive engine misfire results in increased cata-
lyst temperature and causes an increase in HC emis-
sions. Severe misfires could cause catalyst damage.
To prevent catalytic convertor damage, the PCM
monitors engine misfire.
The Powertrain Control Module (PCM) monitors
for misfire during most engine operating conditions
(positive torque) by looking at changes in the crank-
shaft speed. If a misfire occurs the speed of the
crankshaft will vary more than normal.
FUEL SYSTEM MONITOR
To comply with clean air regulations, vehicles are
equipped with catalytic converters. These converters
reduce the emission of hydrocarbons, oxides of nitro-
gen and carbon monoxide. The catalyst works best
when the Air Fuel (A/F) ratio is at or near the opti-
mum of 14.7 to 1.
The PCM is programmed to maintain the optimum
air/fuel ratio of 14.7 to 1. This is done by making
short term corrections in the fuel injector pulse width
based on the O2S sensor output. The programmed
memory acts as a self calibration tool that the engine
controller uses to compensate for variations in engine
specifications, sensor tolerances and engine fatigue
over the life span of the engine. By monitoring the
actual fuel-air ratio with the O2S sensor (short term)
and multiplying that with the program long-term
(adaptive) memory and comparing that to the limit,
it can be determined whether it will pass an emis-
sions test. If a malfunction occurs such that the PCM
cannot maintain the optimum A/F ratio, then the
MIL will be illuminated.
CATALYST MONITOR
To comply with clean air regulations, vehicles are
equipped with catalytic converters. These converters
reduce the emission of hydrocarbons, oxides of nitro-
gen and carbon monoxide.
Normal vehicle miles or engine misfire can cause a
catalyst to decay. This can increase vehicle emissions
and deteriorate engine performance, driveability and
fuel economy.
25 - 18 EMISSIONS CONTROLBR/BE
EMISSIONS CONTROL (Continued)