1998 DODGE RAM 1500 Fluid

TRANSFER CASE - NV271
TABLE OF CONTENTS
page page
TRANSFER CASE - NV271
DESCRIPTION........................447
OPERATION..........................448
DIAGNOSIS AND TESTING - TRANSFER
CASE - NV271.......................448
REMOVAL............................450
DISASSEMBLY........................450
CLEANING...........................459
INSPECTION.........................459
ASSEMBLY...........................461
INSTALLATION........................473
SPECIFICATIONS
TRANSFER CASE - NV271.............473
SPECIAL TOOLS
TRANSFER CASE NV271/NV273.........474
EXTENSION HOUSING SEAL AND DUST BOOT
REMOVAL............................476INSTALLATION........................476
FLUID
STANDARD PROCEDURE - FLUID DRAIN AND
REFILL............................476
FRONT OUTPUT SHAFT SEAL
REMOVAL............................477
INSTALLATION........................477
POSITION SENSOR
DESCRIPTION........................477
OPERATION..........................477
REMOVAL............................478
INSTALLATION........................478
SHIFT LEVER
REMOVAL............................479
INSTALLATION........................480
ADJUSTMENTS
ADJUSTMENT - SHIFT LEVER..........481
TRANSFER CASE - NV271
DESCRIPTION
The NV271 transfer case is a part-time transfer
case with a low-range gear system. It provides three
operating ranges plus a NEUTRAL position. The low
range position provides a gear reduction ratio of
2.72:1 for increased low speed torque capability.
The gear cases and extension are all of aluminum
(Fig. 1). Drive sprockets and an interconnecting drive
chain are used to transmit engine torque to the front/
rear propeller shafts. The mainshaft, input gear and
front output shaft are supported by ball and needle
bearings.
Fig. 1 Transfer Case - Front View
1 - TRANSFER CASE
2 - MANUAL LEVER
3 - POSITION SENSOR
DRTRANSFER CASE - NV271 21 - 447

DIAGNOSIS CHART
Condition Possible Cause Correction
Transfer Case difficult to shift or will not
shift into desired range.1) Vehicle speed too great to permit
shifting.1) Stop vehicle and shift into desired
range. Or, reduce speed to below 3-4
km/h (2-3 mph) before attempting the
shift.
2) If vehicle was operated for an
extended period in 4H on a dry paved
surface, the driveline torque load may
be causing a bind.2) Stop vehicle and shift the
transmission into neutral. Shift the
transfer case to 2H and operate vehicle
in 2H on dry paved surfaces.
3) Transfer case external shift linkage
binding.3) Lubricate, repair, or replace linkage
bushings, or tighten loose components
as necessary.
4) Insufficient or incorrect lubricant. 4) Drain and refill to edge of fill hole
with MoparTATF +4, Automatic
Transmission fluid.
5) Internal components binding, worn,
or damaged.5) Disassemble the transfer case and
replace worn or damaged components
as necessary.
Transfer Case noisy in all operating
ranges.1) Insufficient or incorrect lubricant. 1) Drain and refill to edge of fill hole
with MoparTATF +4, Automatic
Transmission fluid.
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.
DRTRANSFER CASE - NV271 21 - 449
TRANSFER CASE - NV271 (Continued)

(16) Remove the rear output shaft bearing from
the rear case using Installer 7888 (Fig. 54).
(17) Install the rear output shaft bearing (Fig. 55)
into the rear case using Installer 8152 and Handle
C-4171.
(18) Install the rear output shaft bearing snap-
ring into the rear case half.INPUT AND PLANETARY GEAR
(1) Lubricate gears and thrust washers with rec-
ommended transmission fluid.
(2) Install bottom thrust washer (Fig. 56) in low
range gear planetary. Be sure washer tabs are prop-
erly aligned in gear notches.
(3) Install input gear in low range gear (Fig. 57).
Be sure input gear is fully seated.
Fig. 54 Remove Rear Output Shaft Bearing
1 - REAR CASE HALF
2 - INSTALLER 7888
Fig. 55 Install Rear Output Shaft Bearing
1 - REAR CASE HALF
2 - HANDLE C-4171
3 - INSTALLER 8152
Fig. 56 Install Bottom Input Gear Thrust Plate
1 - PLANETARY
2 - THRUST PLATE
Fig. 57 Install Input Gear From Planetary
1 - INPUT GEAR
2 - LOW RANGE PLANETARY
21 - 464 TRANSFER CASE - NV271DR
TRANSFER CASE - NV271 (Continued)

(7) Install snap-ring to hold input/low range gear
into front bearing (Fig. 62).
(8) Install a new input gear seal using Installer
8841 and Handle C-4171.
(9) Install a new input gear oil seal with Installer
9036 and Handle C-4171.
SHIFT FORKS AND MAINSHAFT
(1) Lubricate mainshaft splines with recommended
transmission fluid.
(2) Coat the interior of the drive sprocket hub with
ATF+4 and install the drive sprocket drive hub (Fig.
63) onto the mainshaft.(3) Install the mode hub (Fig. 64) onto the main-
shaft.
(4) Install the mode hub retaining ring (Fig. 65)
onto the mainshaft.
Fig. 62 Install Input Gear Retaining Ring
1 - INPUT GEAR
2 - RETAINING RING
Fig. 63 Install the Drive Sprocket Drive Hub
1 - MAINSHAFT
2 - DRIVE SPROCKET DRIVE HUB
Fig. 64 Install Mode Hub
1 - MAINSHAFT
2 - MODE HUB
Fig. 65 Install Mode Hub Retaining Ring
1 - MAINSHAFT
2 - MODE HUB
3 - RETAINING RING
21 - 466 TRANSFER CASE - NV271DR
TRANSFER CASE - NV271 (Continued)

(5) Install the clutch gear (Fig. 66) onto the output
shaft. Verify that the pointed ends of the clutch gear
teeth are pointing to the front of the mainshaft.
(6) Lubricate sector shaft with transmission fluid
and install shift sector in case (Fig. 67). Position slot
in sector so it will be aligned with shift fork pin
when shift forks are installed.
(7) Apply LoctiteŸ 242, or equivalent, to the
threads of the sector support to replentish the factory
applied patch. Install the shift sector support.
Tighten the sector support with Socket 9033 to 27-34
N´m (20-25 ft.lbs.).(8) Assemble and install range fork and hub (Fig.
68). Be sure hub is properly seated in low range gear
and engaged to the input gear.
(9) Align and insert range fork pin in shift sector
slot.
(10) Install mode fork and shift rail onto the mode
sleeve.
(11) Install the mode fork, sleeve, and shift rail
into the transfer case (Fig. 69).
Fig. 66 Install Clutch Gear
1 - OUTPUT SHAFT
2 - CLUTCH GEAR
3 - MODE HUB
Fig. 67 Install Shift Sector
1 - SHIFT SECTOR
Fig. 68 Install Range Fork And Hub Assembly
1 - RANGE HUB
2 - RANGE FORK
Fig. 69 Install Mode Fork, Sleeve, and Shift Rail
Assembly
1 - SHIFT RAIL
2 - MODE FORK
3 - MODE SLEEVE
DRTRANSFER CASE - NV271 21 - 467
TRANSFER CASE - NV271 (Continued)

(7) Install the front companion flange onto the
front output shaft.
(8) Install two bolts 180É apart into the front out-
put shaft companion flange.
(9) Place holder over the bolts and against the
companion flange (Fig. 90).
(10) Install a new front companion flange nut.
Tighten the companion flange nut to 176-271 N´m
(130-200 ft.lbs.).
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) Remove jack stand from under transmission.
(4) Align and connect propeller shafts. (Refer to 3 -
DIFFERENTIAL & DRIVELINE/PROPELLER
SHAFT/PROPELLER SHAFT - INSTALLATION)
(5) Connect vent hose and transfer case position
sensor connector.
(6) Connect shift rod to transfer case lever or floor
shift arm. Use channel lock style pliers to press rod
back into lever grommet.
(7) Adjust shift linkage, if necessary.(8) Fill transfer case with recommended transmis-
sion fluid and install fill plug.
(9) Install skid plate, if equipped. (Refer to 13 -
FRAMES & BUMPERS/FRAME/TRANSFER CASE
SKID PLATE - INSTALLATION)
(10) Lower vehicle
SPECIFICATIONS
TRANSFER CASE - NV271
TORQUE SPECIFICATIONS
DESCRIPTION N-m Ft. Lbs. In. Lbs.
Plug, Detent 16-25 12-18 -
Plug, Drain/Fill 20-34 15-25 -
Bolt, Extension Housing 27-34 20-25 -
Bolt, Case Half 27-34 20-25 -
Nut, Range Lever 27-34 20-25 -
Sector Support 27-34 20-25 -
Nuts, Mounting 30-41 20-30 -
Position Sensor 20-34 15-25 -
Nut, Companion Flange 176-271 130-200 -
Fig. 90 Install Companion Flange Nut
1 - HOLDER 6719
2 - BOLTS
DRTRANSFER CASE - NV271 21 - 473
TRANSFER CASE - NV271 (Continued)

EXTENSION HOUSING SEAL
AND DUST BOOT
REMOVAL
(1) Raise and support vehicle.
(2) Remove rear propeller shaft. (Refer to 3 - DIF-
FERENTIAL & DRIVELINE/PROPELLER SHAFT/
PROPELLER SHAFT - REMOVAL)
(3) Use a suitable chisel or pry tool to remove the
rear extension housing dust boot (Fig. 91).
(4) Use a suitable chisel or pry tool to remove the
rear extension housing seal.
INSTALLATION
(1) Clean fluid residue from sealing surface and
inspect for defects.
(2) Install the extension housing dust boot and
seal assembly with Installer 9037 and Handle C-4171
(Fig. 92).
(3) Install propeller shaft. (Refer to 3 - DIFFER-
ENTIAL & DRIVELINE/PROPELLER SHAFT/PRO-
PELLER SHAFT - INSTALLATION)
(4) Verify proper transfer case fluid level.
(5) Lower vehicle.
FLUID
STANDARD PROCEDURE - FLUID DRAIN AND
REFILL
The fill and drain plugs are both in the rear case
(Fig. 93).
(1) Raise vehicle.(2) Position drain pan under transfer case.
(3) Remove drain and fill plugs and drain lubri-
cant completely.
(4) Install drain plug. Tighten plug to 41-54 N´m
(30-40 ft. lbs.).
(5) Remove drain pan.
Fig. 91 Remove Extension Housing Dust Boot
1 - EXTENSION HOUSING
2 - DUST BOOT
Fig. 92 Install Extension Housing Seal
1 - EXTENSION HOUSING
2 - HANDLE C-4171
3 - INSTALLER 9037
Fig. 93 Drain and Fill Locations
1 - FILL HOLE
2 - DRAIN HOLE
21 - 476 TRANSFER CASE - NV271DR

(6) Fill transfer case to bottom edge of fill plug
opening with MopartATF +4, Automatic Transmis-
sion fluid.
(7) Install and tighten fill plug to 41-54 N´m
(30-40 ft. lbs.).
(8) Lower vehicle.
FRONT OUTPUT SHAFT SEAL
REMOVAL
(1) Remove the front propeller shaft (Refer to 3 -
DIFFERENTIAL & DRIVELINE/PROPELLER
SHAFT/PROPELLER SHAFT - REMOVAL).
(2) Install two bolts 180É apart into the front out-
put shaft companion flange.
(3) Place holder over the bolts and against the
companion flange (Fig. 94).
(4) Remove and discard the front companion flange
nut.
(5) Remove the companion flange from the front
output shaft. It may be necessary to use Flange
puller 8992 to remove the companion flange.
(6) Using a screw and a slide hammer, remove the
front output shaft seal.
INSTALLATION
(1) Install the new front output shaft seal with
Installer MB991168A.
(2) Install the front companion flange onto the
front output shaft.
(3) Install two bolts 180É apart into the front out-
put shaft companion flange.(4) Place holder over the bolts and against the
companion flange (Fig. 95).
(5) Install a new front companion flange nut.
Tighten the companion flange nut to 258-312 N´m
(190-230 ft.lbs.).
(6) Install front propeller shaft (Refer to 3 - DIF-
FERENTIAL & DRIVELINE/PROPELLER SHAFT/
PROPELLER SHAFT - INSTALLATION).
POSITION SENSOR
DESCRIPTION
The transfer case position sensor is an electronic
device whose output can be interpreted to indicate
the transfer case's current operating mode. The sen-
sor consists of a five position, resistive multiplexed
circuit which returns a specific resistance value to
the Powertrain Control Module (PCM) for each trans-
fer case operating mode. The sensor is located on the
top of the transfer case, just left of the transfer case
centerline and rides against the sector plate rooster-
comb. The PCM supplies 5VDC (+/- 0.5V) to the sen-
sor and monitors the return voltage to determine the
sector plate, and therefore the transfer case, position.
OPERATION
During normal vehicle operation, the Powertrain
Control Module (PCM) monitors the transfer case
position sensor return voltage to determine the oper-
ating mode of the transfer case. Refer to the Operat-
ing Mode Versus Resistance table for the correct
resistance for each position (Fig. 96).
Fig. 94 Remove Companion Flange Nut
1 - HOLDER 6719
2 - BOLTS
Fig. 95 Install Companion Flange Nut
1 - HOLDER 6719
2 - BOLTS
DRTRANSFER CASE - NV271 21 - 477
FLUID (Continued)