ECO mode DODGE RAM 2001 Service Manual Online

(17) Raise transmission slightly with service jack
to relieve load on crossmember and supports.
(18) Remove bolts securing rear support and cush-
ion to transmission and crossmember. Raise trans-
mission slightly, slide exhaust hanger arm from
bracket (Fig. 15) and remove rear support.
(19) Remove bolts attaching crossmember to frame
and remove crossmember.
(20) On4x4models, remove transfer case with
transmission jack or aid of helper.
(21) Remove all converter housing bolts.
(22) Carefully work transmission and torque con-
verter assembly rearward off engine block dowels.
(23) Lower transmission and remove assembly
from under the vehicle.
(24) To remove torque converter, remove C-clamp
from edge of bell housing and carefully slide torque
converter out of the transmission.
DISASSEMBLY
(1) Clean transmission exterior with steam gun or
with solvent. Wear eye protection during cleaning
operations.
(2) Place transmission in a vertical position.
(3)
Measure input shaft end play as follows (Fig. 16).
(a) Attach Adapter 8266-6 to Handle 8266-8.
(b) Attach dial indicator C-3339 to Handle
8266-8.
(c)
Install the assembled tool onto the input shaft
of the transmission and tighten the retaining screw
on Adapter 8266-6 to secure it to the input shaft.
(d)Position the dial indicator plunger against a
flat spot on the oil pump and zero the dial indicator.
(e) Move the input shaft in and out. Record the
maximum travel for assembly reference.(4) Remove shift and throttle levers from valve
body manual lever shaft.
(5) Place transmission in horizontal position.
(6) Remove transmission oil pan and gasket.
(7) Remove filter from valve body (Fig. 17). Keep
filter screws separate from other valve body screws.
Filter screws are longer and should be kept with fil-
ter.
Fig. 15 Rear Support Cushion
1 - EXHAUST PIPE ARM AND BRACKET
2 - CROSSMEMBER
3 - REAR SUPPORT AND CUSHION
Fig. 16 Checking Input Shaft End Play
1 - TOOL 8266-8
2 - TOOL 8266-6
3 - TOOL C-3339
Fig. 17 Oil Filter Removal
1 - OIL FILTER
2 - VALVE BODY
3 - FILTER SCREWS (2)
BR/BEAUTOMATIC TRANSMISSION - 44RE 21 - 331
AUTOMATIC TRANSMISSION - 44RE (Continued)

vary due to various environmental factors or manu-
facturing tolerances.
The pressure transducer is affected by barometric
pressure as well as temperature. Calibration of the
zero pressure offset is required to compensate for
shifting output due to these factors.
Normal calibration will be performed when sump
temperature is above 50 degrees F, or in the absence
of sump temperature data, after the first 10 minutes
of vehicle operation. Calibration of the pressure
transducer offset occurs each time the output shaft
speed falls below 200 RPM. Calibration shall be
repeated each 3 seconds the output shaft speed is
below 200 RPM. A 0.5 second pulse of 95% duty cycle
is applied to the governor pressure solenoid valve
and the transducer output is read during this pulse.
Averaging of the transducer signal is necessary to
reject electrical noise.
Under cold conditions (below 50 degrees F sump),
the governor pressure solenoid valve response may
be too slow to guarantee 0 psi during the 0.5 second
calibration pulse. Calibration pulses are continued
during this period, however the transducer output
valves are discarded. Transducer offset must be read
at key-on, under conditions which promote a stable
reading. This value is retained and becomes the off-
set during the9cold9period of operation.
GOVERNOR PRESSURE SOLENOID VALVE
The inlet side of the solenoid valve is exposed to
normal transmission line pressure. The outlet side of
the valve leads to the valve body governor circuit.
The solenoid valve regulates line pressure to pro-
duce governor pressure. The average current sup-
plied to the solenoid controls governor pressure. One
amp current produces zero kPa/psi governor pres-
sure. Zero amps sets the maximum governor pres-
sure.
The powertrain control module (PCM) turns on the
trans control relay which supplies electrical power to
the solenoid valve. Operating voltage is 12 volts
(DC). The PCM controls the ground side of the sole-
noid using the governor pressure solenoid control cir-
cuit.
GOVERNOR PRESSURE SENSOR
The sensor output signal provides the necessary
feedback to the PCM. This feedback is needed to ade-
quately control governor pressure.
GOVERNOR BODY AND TRANSFER PLATE
The transfer plate channels line pressure to the
solenoid valve through the governor body. It also
channels governor pressure from the solenoid valve
to the governor circuit. It is the solenoid valve that
develops the necessary governor pressure.
GOVERNOR PRESSURE CURVES
LOW TRANSMISSION FLUID TEMPERATURE
When the transmission fluid is cold the conven-
tional governor can delay shifts, resulting in higher
than normal shift speeds and harsh shifts. The elec-
tronically controlled low temperature governor pres-
sure curve is higher than normal to make the
transmission shift at normal speeds and sooner. The
PCM uses a temperature sensor in the transmission
oil sump to determine when low temperature gover-
nor pressure is needed.
NORMAL OPERATION
Normal operation is refined through the increased
computing power of the PCM and through access to
data on engine operating conditions provided by the
PCM that were not available with the previous
stand-alone electronic module. This facilitated the
development of a load adaptive shift strategy - the
ability to alter the shift schedule in response to vehi-
cle load condition. One manifestation of this capabil-
ity is grade9hunting9prevention - the ability of the
transmission logic to delay an upshift on a grade if
the engine does not have sufficient power to main-
tain speed in the higher gear. The 3-2 downshift and
the potential for hunting between gears occurs with a
heavily loaded vehicle or on steep grades. When
hunting occurs, it is very objectionable because shifts
are frequent and accompanied by large changes in
noise and acceleration.
WIDE OPEN THROTTLE OPERATION
In wide-open throttle (WOT) mode, adaptive mem-
ory in the PCM assures that up-shifts occur at the
preprogrammed optimum speed. WOT operation is
determined from the throttle position sensor, which
is also a part of the emission control system. The ini-
tial setting for the WOT upshift is below the opti-
mum engine speed. As WOT shifts are repeated, the
PCM learns the time required to complete the shifts
by comparing the engine speed when the shifts occur
to the optimum speed. After each shift, the PCM
adjusts the shift point until the optimum speed is
reached. The PCM also considers vehicle loading,
grade and engine performance changes due to high
altitude in determining when to make WOT shifts. It
does this by measuring vehicle and engine accelera-
tion and then factoring in the shift time.
TRANSFER CASE LOW RANGE OPERATION
On four-wheel drive vehicles operating in low
range, the engine can accelerate to its peak more
rapidly than in Normal range, resulting in delayed
shifts and undesirable engine9flare.9The low range
governor pressure curve is also higher than normal
21 - 366 AUTOMATIC TRANSMISSION - 44REBR/BE
ELECTRONIC GOVERNOR (Continued)

OVERDRIVE CLUTCH
DESCRIPTION
The overdrive clutch (Fig. 113) is composed of the
pressure plate, clutch plates, holding discs, overdrive
piston retainer, piston, piston spacer, and snap-rings.
The overdrive clutch is the forwardmost component
in the transmission overdrive unit and is considered
a holding component. The overdrive piston retainer,
piston, and piston spacer are located on the rear of
the main transmission case.
NOTE: The number of discs and plates may vary
with each engine and vehicle combination.
OPERATION
To apply the clutch, pressure is applied between the
piston retainer and piston. The fluid pressure is pro-
vided by the oil pump, transferred through the control
valves and passageways, and enters the clutch through
passages at the lower rear portion of the valve body
area. With pressure applied between the piston retainer
and piston, the piston moves away from the piston
retainer and compresses the clutch pack. This action
applies the clutch pack, allowing torque to flow through
the intermediate shaft into the overdrive planetary gear
set. The overdrive clutch discs are attached to the over-
drive clutch hub while the overdrive clutch plates, reac-
tion plate, and pressure plate are lugged to the
overdrive housing. This allows the intermediate shaft totransfer the engine torque to the planetary gear and
overrunning clutch. This drives the planetary gear
inside the annulus, which is attached to the overdrive
clutch drum and output shaft, creating the desired gear
ratio. The waved snap-ring is used to cushion the appli-
cation of the clutch pack.
OVERDRIVE SWITCH
DESCRIPTION
The overdrive OFF (control) switch is located in
the shift lever arm (Fig. 114). The switch is a
momentary contact device that signals the PCM to
toggle current status of the overdrive function.
OPERATION
At key-on, overdrive operation is allowed. Pressing
the switch once causes the overdrive OFF mode to be
entered and the overdrive OFF switch lamp to be illu-
minated. Pressing the switch a second time causes nor-
mal overdrive operation to be restored and the overdrive
lamp to be turned off. The overdrive OFF mode defaults
to ON after the ignition switch is cycled OFF and ON.
The normal position for the control switch is the ON
position. The switch must be in this position to energize
the solenoid and allow a 3-4 upshift. The control switch
indicator light illuminates only when the overdrive
switch is turned to the OFF position, or when illumi-
nated by the transmission control module.
Fig. 113 Overdrive Clutch
1 - REACTION PLATE 2 - PRESSURE PLATE
BR/BEAUTOMATIC TRANSMISSION - 44RE 21 - 385

(12) Disconnect wires from park/neutral position
switch and transmission solenoid.
(13) Disconnect gearshift rod and torque shaft
assembly from transmission.
(14) Disconnect throttle valve cable from transmis-
sion bracket and throttle valve lever.
(15) On4x4models, disconnect shift rod from
transfer case shift lever.
(16)
Support rear of engine with safety stand or jack.
(17) Raise transmission slightly with service jack
to relieve load on crossmember and supports.
(18) Remove bolts securing rear support and cush-
ion to transmission and crossmember. Raise trans-
mission slightly, slide exhaust hanger arm from
bracket (Fig. 15) and remove rear support.(19) Remove bolts attaching crossmember to frame
and remove crossmember.
(20) On4x4models, remove transfer case with
transmission jack or aid of helper.
(21) Remove all converter housing bolts.
(22) Carefully work transmission and torque con-
verter assembly rearward off engine block dowels.
(23) Lower transmission and remove assembly
from under the vehicle.
(24) To remove torque converter, remove C-clamp
from edge of bell housing and carefully slide torque
converter out of the transmission.
DISASSEMBLY
(1) Clean exterior of transmission with suitable
solvent or pressure washer.
(2) Place transmission in vertical position.
(3) Measure the input shaft end play as follows
(Fig. 16).
(a) Attach Adapter 8266-5 to Handle 8266-8.
(b) Attach dial indicator C-3339 to Handle
8266-8.
(c)
Install the assembled tool onto the input shaft
of the transmission and tighten the retaining screw
on Adapter 8266-5 to secure it to the input shaft.
(d)Position the dial indicator plunger against a
flat spot on the oil pump and zero the dial indicator.
(e)Move input shaft in and out and record read-
ing. Record the maximum travel for assembly refer-
ence
Fig. 14 Fill Tube Attachment
1 - TRANSFER CASE VENT TUBE
2 - FILL TUBE (V8)
3 - TUBE SEAL
4 - FILL TUBE (V6)
Fig. 15 Rear Support Cushion
1 - EXHAUST PIPE ARM AND BRACKET
2 - CROSSMEMBER
3 - REAR SUPPORT AND CUSHION
Fig. 16 Checking Input Shaft End Play
1 - TOOL 8266-8
2 - TOOL 8266-5
3 - TOOL C-3339
BR/BEAUTOMATIC TRANSMISSION - 46RE 21 - 503
AUTOMATIC TRANSMISSION - 46RE (Continued)

during wide-open throttle operation. The fourth curve
is used when driving with the transfer case in low
range.
OPERATION
Compensation is required for performance varia-
tions of two of the input devices. Though the slope of
the transfer functions is tightly controlled, offset may
vary due to various environmental factors or manu-
facturing tolerances.
The pressure transducer is affected by barometric
pressure as well as temperature. Calibration of the
zero pressure offset is required to compensate for
shifting output due to these factors.
Normal calibration will be performed when sump
temperature is above 50 degrees F, or in the absence
of sump temperature data, after the first 10 minutes
of vehicle operation. Calibration of the pressure
transducer offset occurs each time the output shaft
speed falls below 200 RPM. Calibration shall be
repeated each 3 seconds the output shaft speed is
below 200 RPM. A 0.5 second pulse of 95% duty cycle
is applied to the governor pressure solenoid valve
and the transducer output is read during this pulse.
Averaging of the transducer signal is necessary to
reject electrical noise.
Under cold conditions (below 50 degrees F sump),
the governor pressure solenoid valve response may
be too slow to guarantee 0 psi during the 0.5 second
calibration pulse. Calibration pulses are continued
during this period, however the transducer output
valves are discarded. Transducer offset must be read
at key-on, under conditions which promote a stable
reading. This value is retained and becomes the off-
set during the9cold9period of operation.
GOVERNOR PRESSURE SOLENOID VALVE
The inlet side of the solenoid valve is exposed to
normal transmission line pressure. The outlet side of
the valve leads to the valve body governor circuit.
The solenoid valve regulates line pressure to pro-
duce governor pressure. The average current sup-
plied to the solenoid controls governor pressure. One
amp current produces zero kPa/psi governor pres-
sure. Zero amps sets the maximum governor pres-
sure.
The powertrain control module (PCM) turns on the
trans control relay which supplies electrical power to
the solenoid valve. Operating voltage is 12 volts
(DC). The PCM controls the ground side of the sole-
noid using the governor pressure solenoid control cir-
cuit.
GOVERNOR PRESSURE SENSOR
The sensor output signal provides the necessary
feedback to the PCM. This feedback is needed to ade-
quately control governor pressure.
GOVERNOR BODY AND TRANSFER PLATE
The transfer plate channels line pressure to the
solenoid valve through the governor body. It also
channels governor pressure from the solenoid valve
to the governor circuit. It is the solenoid valve that
develops the necessary governor pressure.
GOVERNOR PRESSURE CURVES
LOW TRANSMISSION FLUID TEMPERATURE
When the transmission fluid is cold the conven-
tional governor can delay shifts, resulting in higher
than normal shift speeds and harsh shifts. The elec-
tronically controlled low temperature governor pres-
sure curve is higher than normal to make the
transmission shift at normal speeds and sooner. The
PCM uses a temperature sensor in the transmission
oil sump to determine when low temperature gover-
nor pressure is needed.
NORMAL OPERATION
Normal operation is refined through the increased
computing power of the PCM and through access to
data on engine operating conditions provided by the
PCM that were not available with the previous
stand-alone electronic module. This facilitated the
development of a load adaptive shift strategy - the
ability to alter the shift schedule in response to vehi-
cle load condition. One manifestation of this capabil-
ity is grade9hunting9prevention - the ability of the
transmission logic to delay an upshift on a grade if
the engine does not have sufficient power to main-
tain speed in the higher gear. The 3-2 downshift and
the potential for hunting between gears occurs with a
heavily loaded vehicle or on steep grades. When
hunting occurs, it is very objectionable because shifts
are frequent and accompanied by large changes in
noise and acceleration.
WIDE OPEN THROTTLE OPERATION
In wide-open throttle (WOT) mode, adaptive mem-
ory in the PCM assures that up-shifts occur at the
preprogrammed optimum speed. WOT operation is
determined from the throttle position sensor, which
is also a part of the emission control system. The ini-
tial setting for the WOT upshift is below the opti-
mum engine speed. As WOT shifts are repeated, the
PCM learns the time required to complete the shifts
by comparing the engine speed when the shifts occur
to the optimum speed. After each shift, the PCM
adjusts the shift point until the optimum speed is
BR/BEAUTOMATIC TRANSMISSION - 46RE 21 - 541
ELECTRONIC GOVERNOR (Continued)

OPERATION
At key-on, overdrive operation is allowed. Pressing
the switch once causes the overdrive OFF mode to be
entered and the overdrive OFF switch lamp to be illu-
minated. Pressing the switch a second time causes nor-
mal overdrive operation to be restored and the overdrive
lamp to be turned off. The overdrive OFF mode defaults
to ON after the ignition switch is cycled OFF and ON.
The normal position for the control switch is the ON
position. The switch must be in this position to energize
the solenoid and allow a 3-4 upshift. The control switch
indicator light illuminates only when the overdrive
switch is turned to the OFF position, or when illumi-
nated by the transmission control module.
DIAGNOSIS AND TESTING - OVERDRIVE
ELECTRICAL CONTROLS
The overdrive off switch, valve body solenoid, case
connectors and related wiring can all be tested with
a 12 volt test lamp or a volt/ohmmeter. Check conti-
nuity of each component when diagnosis indicates
this is necessary.
Switch and solenoid continuity should be checked
whenever the transmission fails to shift into fourth
gear range.
REMOVAL
(1) Using a plastic trim tool, remove the overdrive
off switch retainer from the shift lever (Fig. 183).
(2) Pull the switch outwards to release it from the
connector in the lever (Fig. 184)
INSTALLATION
NOTE: There is enough slack in the wire to pull out
the connector from the lever.
(1) Pull the connector out of the lever just enough
to grasp it.
CAUTION: Be careful not to bend the pins on the
overdrive off switch. Use care when installing the
switch, as it is not indexed, and can be accidentally
installed incorrectly.
(2) Install the overdrive off switch into the connec-
tor (Fig. 185)
Fig. 183 Overdrive Off Switch Retainer
1 - GEAR SHIFT LEVER
2 - OVERDRIVE OFF SWITCH RETAINER
3 - PLASTIC TRIM TOOL
Fig. 184 Remove the Overdrive Off Switch
1 - GEAR SHIFT LEVER
2 - OVERDRIVE OFF SWITCH
Fig. 185 Install the Overdrive Off Switch
1 - GEAR SHIFT LEVER
2 - OVERDRIVE OFF SWITCH WIRING CONNECTOR
3 - OVERDRIVE OFF SWITCH
BR/BEAUTOMATIC TRANSMISSION - 46RE 21 - 579
OVERDRIVE SWITCH (Continued)

(12) Disconnect wires from park/neutral position
switch and transmission solenoid.
(13) Disconnect gearshift rod and torque shaft
assembly from transmission.
(14) Disconnect throttle valve cable from transmis-
sion bracket and throttle valve lever.
(15) On4x4models, disconnect shift rod from
transfer case shift lever.
(16)
Support rear of engine with safety stand or jack.
(17) Raise transmission slightly with service jack
to relieve load on crossmember and supports.
(18) Remove bolts securing rear support and cush-
ion to transmission and crossmember. Raise trans-
mission slightly, slide exhaust hanger arm from
bracket (Fig. 15) and remove rear support.(19) Remove bolts attaching crossmember to frame
and remove crossmember.
(20) On4x4models, remove transfer case with
transmission jack or aid of helper.
(21) Remove all converter housing bolts.
(22) Carefully work transmission and torque con-
verter assembly rearward off engine block dowels.
(23) Lower transmission and remove assembly
from under the vehicle.
(24) To remove torque converter, remove C-clamp
from edge of bell housing and carefully slide torque
converter out of the transmission.
DISASSEMBLY
(1) Clean exterior of transmission with suitable
solvent or pressure washer.
(2) Place transmission in vertical position.
(3) Measure the input shaft end play as follows
(Fig. 16).
(a) Attach Adapter 8266-5 to Handle 8266-8.
(b)
Attach dial indicator C-3339 to Handle 8266-8.
(c)Install the assembled tool onto the input shaft
of the transmission and tighten the retaining screw
on Adapter 8266-5 to secure it to the input shaft.
(d) Position the dial indicator plunger against a
flat spot on the oil pump and zero the dial indica-
tor.
(e) Move input shaft in and out and record read-
ing. Record the maximum travel for assembly ref-
erence
Fig. 14 Fill Tube Attachment
1 - TRANSFER CASE VENT TUBE
2 - FILL TUBE (V8)
3 - TUBE SEAL
4 - FILL TUBE (V6)
Fig. 15 Rear Support Cushion
1 - EXHAUST PIPE ARM AND BRACKET
2 - CROSSMEMBER
3 - REAR SUPPORT AND CUSHION
Fig. 16 Checking Input Shaft End Play
1 - TOOL 8266-8
2 - TOOL 8266-5
3 - TOOL C-3339
21 - 674 AUTOMATIC TRANSMISSION - 47REBR/BE
AUTOMATIC TRANSMISSION - 47RE (Continued)

drum and output shaft, creating the desired gear
ratio. The waved snap-ring is used to cushion the
application of the clutch pack.
OVERDRIVE SWITCH
DESCRIPTION
The overdrive OFF (control) switch is located in
the shift lever arm (Fig. 113). The switch is a
momentary contact device that signals the PCM to
toggle current status of the overdrive function.
OPERATION
At key-on, overdrive operation is allowed. Pressing
the switch once causes the overdrive OFF mode to be
entered and the overdrive OFF switch lamp to be
illuminated. Pressing the switch a second time
causes normal overdrive operation to be restored and
the overdrive lamp to be turned off. The overdrive
OFF mode defaults to ON after the ignition switch is
cycled OFF and ON. The normal position for the con-
trol switch is the ON position. The switch must be in
this position to energize the solenoid and allow a 3-4
upshift. The control switch indicator light illuminates
only when the overdrive switch is turned to the OFF
position, or when illuminated by the transmission
control module.
DIAGNOSIS AND TESTING - OVERDRIVE
ELECTRICAL CONTROLS
The overdrive off switch, valve body solenoid, case
connectors and related wiring can all be tested with
a 12 volt test lamp or a volt/ohmmeter. Check conti-
nuity of each component when diagnosis indicates
this is necessary.
Switch and solenoid continuity should be checked
whenever the transmission fails to shift into fourth
gear range.
Fig. 112 Overdrive Clutch
1 - REACTION PLATE 2 - PRESSURE PLATE
Fig. 113 Overdrive Off Switch
21 - 732 AUTOMATIC TRANSMISSION - 47REBR/BE
OVERDRIVE CLUTCH (Continued)

INSPECTION
MAINSHAFT/SPROCKET/HUB
Inspect the splines on the hub and shaft and the
teeth on the sprocket (Fig. 41). Minor nicks and
scratches can be smoothed with an oilstone, however,
replace any part that is damaged.
Check the contact surfaces in the sprocket bore
and on the mainshaft. Minor nicks and scratches can
be smoothed with 320-400 grit emery cloth but do not
try to salvage the shaft if nicks or wear is severe.
Inspect the spline teeth on the synchronizer hub. If
evidence of chipping or excessive wear is apparent,
replace the hub. The hooked end of each synchronizer
spring should be inserted in one of the struts. In
addition, the springs should not interfere with the
polished gear cone or inside diameters of the hub.
Inspect the stop ring for cracks and wear . Replace
the ring if necessary or if doubt exists over condition.
Check a replacement synchronizer ring for proper fit
on the cone with a minimum of wobble. Also check
the synchronizer struts for wear or damage.
INPUT GEAR AND PLANETARY CARRIER
Check the teeth on the gear (Fig. 42). Minor nicks
can be dressed off with an oilstone but replace the
gear if any teeth are broken, cracked, or chipped. The
bearing surface on the gear can be smoothed with
300-400 grit emery cloth if necessary.Examine the carrier body and pinion gears for
wear or damage. The carrier will have to be replaced
as an assembly if the body, pinion pins, or pinion
gears are damaged.
Check the lock ring and both thrust washers for
wear or cracks. Replace them if necessary. Also
replace the lock retaining ring if bent, distorted, or
broken.
SHIFT FORKS/HUBS/SLEEVES
Check condition of the shift forks and mode fork
shift rail (Fig. 43). Minor nicks on the shift rail can
be smoothed with 320-400 grit emery cloth.
Inspect the shift fork wear pads (Fig. 44). The
mode fork pads are serviceable and can be replaced if
necessary. The range fork pads are not serviceable.
The fork must be replaced as an assembly if the pads
are worn or damaged.
Check both of the sleeves for wear or damage,
especially on the interior teeth. Replace the sleeves if
wear or damage is evident.
REAR RETAINER COMPONENTS
Inspect the retainer components. Replace the bear-
ing if rough or noisy. Check the retainer for cracks or
wear in the bearing bore.
Inspect the retaining rings and washers. Replace
any part if distorted, bent, or broken. Reuse is not
recommended.
Fig. 41 Mainshaft Components
1 - DRIVE SPROCKET 5 - STRUTS
2 - STOP RING 6 - SYNCHRONIZER SPRINGS
3 - SYNCHRONIZER HUB 7 - MAINSHAFT
4 - RETAINING RING
21 - 832 TRANSFER CASE - NV231HDBR/BE
TRANSFER CASE - NV231HD (Continued)

Check a replacement synchronizer ring for proper fit
on the cone with a minimum of wobble. Also check
the synchronizer struts for wear or damage.
Inspect all gear teeth and splines for wear or dam-
age. Also check splines for burrs, or nicks. Remove
minor nicks and scratches with an oil stone. Replace
any part with damaged splines.
It is recommended that all retaining rings be replaced
during overhaul. Most of the retaining rings can be dis-
torted during removal and should not be reused.
Inspect the two case halves, for cracks, porosity,
damaged mating surfaces, stripped bolt threads, or
distortion. Replace either case half if necessary. How-
ever, stripped threads can be repaired with Heli-
CoilŸ stainless steel thread inserts. The case vent
tube can be resecured with LoctiteŸ 680 if necessary.
Inspect the annulus gear. Be sure the gear teeth
are in good condition. Replace the front case and
annulus as an assembly if the gear is damaged.
Check condition of the shift fork pads (Fig. 39).
The pads should be replaced if cracked, worn, or
loose (won't stay on fork).
The shift forks, clutch and sleeve should all be
checked for wear, cracks, or any type of damage (Fig.
40). The shift sector shaft and detents should be
inspected for wear. The mode fork and shift rail are a
one-piece unit. If either part is damaged, replace the
fork and rail as an assembly. Replace the shift rail
cup and spring if they exhibit wear.Inspect the planetary thrust washers (Fig. 41)
carefully for wear or damage. Replace both washers
if necessary.
Fig. 39 Shift Fork Pads
1-PADS
2-PADS
3 - RANGE FORK
4 - MODE FORK
Fig. 40 Shift Fork Components
1 - SUPPORT SLEEVE 5 - MODE FORK AND SHIFT RAIL
2 - RANGE FORK 6 - SPRING
3 - SHIFT SECTOR 7 - CUP
4 - POPPET PLUNGER, SPRING, SCREW 8 - SLIDING CLUTCH
BR/BETRANSFER CASE - NV241HD 21 - 903
TRANSFER CASE - NV241HD (Continued)