2001 DODGE RAM ECU

3-4 ACCUMULATOR
(1) Position converter clutch valve and 3-4 shift
valve springs in housing (Fig. 308).
(2) Loosely attach accumulator housing with right-
side screw (Fig. 308). Install only one screw at this
time as accumulator must be free to pivot upward for
ease of installation.
(3) Install 3-4 shift valve and spring.
(4) Install converter clutch timing valve and
spring.
(5) Position plug on end of converter clutch valve
spring. Then compress and hold springs and plug in
place with fingers of one hand.
(6) Swing accumulator housing upward over valve
springs and plug.
(7) Hold accumulator housing firmly in place and
install remaining two attaching screws. Be sure
springs and clutch valve plug are properly seated
(Fig. 309). Tighten screws to 4 N´m (35 in. lbs.).
VALVE BODY FINAL
(1) Install boost valve, valve spring, retainer and
cover plate. Tighten cover plate screws to 4 N´m (35
in. lbs.) torque.
(2) Insert manual lever detent spring in upper
housing.
(3) Position detent ball on end of spring. Then hold
detent ball and spring in detent housing with
Retainer Tool 6583 (Fig. 310).
(4) Install throttle lever in upper housing. Then
install manual lever over throttle lever and start
manual lever into housing.
(5) Align manual lever with detent ball and man-
ual valve. Hold throttle lever upward. Then press
down on manual lever until fully seated. Remove
detent ball retainer tool after lever is seated.(6) Then install manual lever seal, washer and
E-clip.
(7) Verify that throttle lever is aligned with end of
kickdown valve stem and that manual lever arm is
engaged in manual valve (Fig. 311).
(8) Position line pressure adjusting screw in
adjusting screw bracket.
(9) Install spring on end of line pressure regulator
valve.
(10) Install switch valve spring on tang at end of
adjusting screw bracket.
Fig. 307 Securing Boost Valve Tube With Brace
Tabs
1 - BEND TABS UP AGAINST TUBE AS SHOWNFig. 308 Converter Clutch And 3-4 Shift Valve
Springs
1 - RIGHT-SIDE SCREW
2 - 3-4 ACCUMULATOR
3 - 3-4 SHIFT VALVE SPRING
4 - CONVERTER CLUTCH VALVE SPRING
Fig. 309 Seating 3-4 Accumulator On Lower
Housing
1 - ACCUMULATOR BOX
2 - CONVERTER CLUTCH VALVE PLUG
21 - 816 AUTOMATIC TRANSMISSION - 47REBR/BE
VALVE BODY (Continued)

Condition Possible Cause Correction
Noisy in, or jumps out of, four wheel
drive low range.1) Transfer case not completely
engaged in 4L position.1) With the transmission in
NEUTRAL, or the clutch depressed
in the case of a manual
transmission and the vehicle moving
under 3-4 km/h (2-3 mph), shift the
transfer case to NEUTRAL and then
shift into the 4L position.
2) Shift linkage out of adjustment. 2) Adjust linkage.
3) Shift linkage loose or binding. 3) Tighten, lubricate, or repair
linkage as necessary.
4) Range fork damaged, inserts
worn, or fork is binding on the shift
rail.4) Disassemble unit and repair as
necessary.
5) Low range gear worn or
damaged.5) Disassemble unit and repair as
necessary.
Lubricant leaking from output shaft
seal or vent.1) Transfer case overfilled. 1) Drain lubricant to the correct
level.
2) Vent closed or restricted. 2) Clear or replace vent as
necessary.
3) Output shaft seals damaged or
installed incorrectly.3) Replace seal as necessary.
Check to ensure that another
component, the propeller shaft slip
yoke for example, is not causing
damage to seal.
Abnormal tire wear. 1) Extended operation on hard, dry
surfaces in the 4H position.1) Operate vehicle in the 2H
position on hard, dry surfaces.
REMOVAL
(1) Raise and support vehicle.
(2) Remove skid plate, if equipped. (Refer to 13 -
FRAMES & BUMPERS/FRAME/TRANSFER CASE
SKID PLATE - REMOVAL)
(3) Position drain oil container under transfer
case.
(4) Remove transfer case drain plug and drain
lubricant into container.
(5) Disconnect vent hose and vacuum harness at
transfer case switch.
(6) Disconnect shift rod from grommet in transfer
case shift lever, or from floor shift arm whichever
provides easy access. Use channel lock style pliers to
press rod out of lever grommet.
(7) Support transmission with jack stand.
(8) Remove rear crossmember.
(9) Mark front and rear propeller shafts for assem-
bly reference.(10) Remove front and rear propeller shafts. (Refer
to 3 - DIFFERENTIAL & DRIVELINE/PROPELLER
SHAFT/PROPELLER SHAFT - REMOVAL)
(11) Support transfer case with suitable jack.
Secure transfer case to jack with safety chains.
(12) Remove nuts attaching transfer case to trans-
mission.
(13) Move transfer case assembly rearward until
free of transmission output shaft.
(14) Lower jack and move transfer case from
under vehicle.
DISASSEMBLY
Position transfer case in a shallow drain pan.
Remove drain plug and drain any remaining lubri-
cant remaining in case.
21 - 822 TRANSFER CASE - NV231HDBR/BE
TRANSFER CASE - NV231HD (Continued)

(11) Remove shift sector shaft nylon retainer and
O-ring from shaft bore in front case (Fig. 26).
MAINSHAFT
(1) Remove retaining ring that secures synchro-
nizer hub onto mainshaft (Fig. 27). Use standard
(instead of parallel jaw) snap-ring pliers to remove
this retaining ring.
(2) Remove synchronizer hub (Fig. 28).
Fig. 25 Shift Sector Removal
1 - SHIFT SECTOR
Fig. 26 Removing Sector Shaft O-Ring And Retainer
1 - SHAFT BORE
2 - NYLON RETAINING RING
3 - SECTOR SHAFT O-RING
Fig. 27 Synchronizer Hub Retaining Ring Removal
1 - SYNCHRONIZER HUB
2 - RETAINING RING
Fig. 28 Synchronizer Hub Removal
1 - SYNCHRONIZER HUB
2 - MAINSHAFT
21 - 828 TRANSFER CASE - NV231HDBR/BE
TRANSFER CASE - NV231HD (Continued)

LOW RANGE ANNULUS GEAR
Inspect annulus gear condition carefully. The gear
is only serviced as part of the front case. If the gear
is damaged, it will be necessary to replace the gear
and front case as an assembly. Do not attempt to
remove the gear (Fig. 45)
FRONT-REAR CASES AND FRONT RETAINER
Inspect the cases and retainer for wear and dam-
age. Replace the input retainer seal, do not reuse it.
Check case condition. If leaks were a problem, look
for gouges and severe scoring of case sealing sur-
faces. Also make sure the front case mounting studs
are in good condition.
Check the front case mounting studs and vent
tube. The tube can be secured with LoctiteŸ 271 or
680 if loose. The stud threads can be cleaned up with
a die if necessary. Also check condition of the fill/
drain plug threads in the rear case. The threads can
be repaired with a thread chaser or tap if necessary.
Or the threads can be repaired with HelicoilŸ stain-
less steel inserts if required.
OIL PUMP/OIL PICKUP
Examine the oil pump pickup parts. Replace the
pump if any part appears to be worn or damaged. Do
not disassemble the pump as individual parts are not
available. The pump is only available as a complete
assembly. The pickup screen, hose, and tube are the
only serviceable parts and are available separately.
ASSEMBLY
BEARINGS AND SEALS
(1) Using Remover C-4210 and Handle C-4171,
drive input shaft bearing from case from inside annu-
lus gear opening (Fig. 46).
(2) Install locating ring on new bearing.
(3) Position case so that the forward end is facing
upward.
(4) Using Remover C-4210 and Handle C-4171,
drive input shaft bearing into case. The bearing
locating ring must be fully seated on case (Fig. 47).
(5) Using Installer 6953, remove front output shaft
bearing.
(6) Start front shaft output bearing in case (Fig.
48). Then seat bearing with Handle C-4171 and
Installer 6953.
(7) Install front output bearing retaining ring.
(8) Install new front output seal front case with
Installer Tool 8143-A as follows:
(a) Place new seal on tool. Garter spring on seal
goes toward interior of case.
(b) Start seal in bore with light taps from ham-
mer (Fig. 49). Once seal is started, continue tap-
ping seal into bore until installer tool seats against
case.
(9) Remove seal from front bearing retainer with
suitable pry tool.
(10) Install new oil seal in front bearing retainer
with Installer 7884 (Fig. 50).
Fig. 45 Low Range Annulus Gear
1 - FRONT CASE
2 - LOW RANGE ANNULUS GEAR
Fig. 46 Input Shaft Bearing Removal
1 - SPECIAL TOOL C-4171
2 - SPECIAL TOOL C-4210
21 - 834 TRANSFER CASE - NV231HDBR/BE
TRANSFER CASE - NV231HD (Continued)

(8) Clean gasket sealer residue from retainer and
inspect retainer for cracks or other damage.
(9) Applya3mm(1/8 in.) bead of MopartGasket
Maker, or equivalent silicone adhesive, to sealing
surface of retainer.
(10) Align cavity in seal retainer with fluid return
hole in front of case.
CAUTION: Do not block fluid return cavity on seal-
ing surface of retainer when applying MoparTGas-
ket Maker, or equivalent silicone adhesive sealer.
Seal failure and fluid leak can result.
(11) Install bolts to hold retainer to transfer case
(Fig. 59). Tighten to 21 N´m (16 ft. lbs.) of torque.
SHIFT FORKS AND MAINSHAFT
(1) Lubricate mainshaft splines with recommended
transmission fluid.
(2) Install drive sprocket on mainshaft (Fig. 60).
(3) Install brass stop ring on drive sprocket (Fig.
61).
(4) Install 3 synchro struts and 2 springs in hub as
follows:
(a) Insert first strut in hub (Fig. 62). Strut
shoulders rest (and slide) on sides hub slot as
shown.
(b) Insert hooked end of first spring in center of
strut to secure it. Then work spring into hub (Fig.
63).
Fig. 58 Install Input Gear Snap-Ring
1 - INPUT GEAR
2 - SNAP-RING
Fig. 59 Install Front Bearing Retainer
1 - FRONT BEARING RETAINER
Fig. 60 Drive Sprocket Installation
1 - MAINSHAFT
2 - DRIVE SPROCKET
Fig. 61 Synchro Stop Ring Installation
1 - BRASS STOP RING
2 - DRIVE SPROCKET
21 - 838 TRANSFER CASE - NV231HDBR/BE
TRANSFER CASE - NV231HD (Continued)

(c) Press spring inward and insert last two
struts in hub slots. Be sure spring is positioned
under struts to properly secure them (Fig. 64).
(d) Turn hub over and install remaining spring
in hub. Position hooked end of second spring 180É
away from first spring end.
(5) Install assembled synchro hub on mainshaft
(Fig. 65). Hub has shoulder on one side which goes
toward sprocket (rear of shaft). Flat side of hub faces
front of shaft.
Fig. 62 Installing First Synchro Strut And Spring
1 - FIRST STRUT
2 - SYNCHRONIZER HUB
3 - SPRING
Fig. 63 Synchro Spring Installation
1 - STRUT SHOULDER
2 - SPRING (SEATED IN STRUT)
3 - HUB
Fig. 64 Correct Position Of Struts And Springs
1 - STRUTS
2 - SPRING
Fig. 65 Synchro Hub Installation
1 - SYNCHRONIZER HUB (SHOULDER SIDE DOWN)
2 - STOP RING AND SPROCKET
BR/BETRANSFER CASE - NV231HD 21 - 839
TRANSFER CASE - NV231HD (Continued)

(15) Install vacuum/indicator switch (Fig. 73).
Tighten switch to 20-34 N´m (15-25 ft. lbs.) torque.
Install new O-ring on switch beforehand, if necessary.
(16) Install new sector shaft O-ring and O-ring
retainer in sector shaft bore (Fig. 74). Lubricate
O-ring with transmission fluid or petroleum jelly
after installation.
(17) Install shift lever on sector shaft (Fig. 75).
(18) Install washer and nut on sector shaft to
secure shift lever. Apply 1-2 drops MopartLock N'
Seal, or equivalent, to nut threads before installation.
Then tighten nut to 27-34 N´m (20-25 ft. lbs.) torque.(19) Install poppet plunger and spring (Fig. 76).
(20) Install new O-ring on poppet screw and install
screw in front case (Fig. 77). Tighten screw to 16-24
N´m (12-18 ft. lbs.).
Fig. 73 Vacuum/Indicator Switch Installation
1 - 1-1/16º SOCKET
2 - INDICATOR SWITCH
Fig. 74 Sector Shaft O-Ring And Retainer Installation
1 - SECTOR SHAFT BORE
2 - O-RING
3 - O-RING RETAINER
Fig. 75 Shift Lever Installation
1 - SHIFT LEVER
2 - NUT/WASHER
Fig. 76 Poppet Plunger And Spring Installation
1 - POPPET PLUNGER AND SPRING
Fig. 77 O-Ring Installation On Poppet Plunger
Screw
1 - O-RING
2 - PLUNGER SCREW
21 - 842 TRANSFER CASE - NV231HDBR/BE
TRANSFER CASE - NV231HD (Continued)

(8) Insert magnet in front case pocket (Fig. 82).
OIL PUMP AND REAR CASE
Lubricate the oil pump components with before
installation. 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. 83).
(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. 84).
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. 85).
(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.
Fig. 82 Case Magnet Installation
1 - MAGNET
2 - CASE POCKET
Fig. 83 Pickup Tube O-Ring Installation
1 - O-RING (PUMP PICKUP)
2 - PICKUP TUBE
Fig. 84 Oil Pickup Tube And Filter Position In Rear
Case
1 - FILTER
2 - TUBE AND HOSE
3 - TUBE IN NOTCH
Fig. 85 Positioning Oil Pump In Rear Case
1 - OIL PUMP
2 - REAR CASE
3 - FILTER
4 - PICKUP TUBE
21 - 844 TRANSFER CASE - NV231HDBR/BE
TRANSFER CASE - NV231HD (Continued)