1998 DODGE RAM 1500 FRONT HUB

IDENTIFICATION
An identification tag (Fig. 2) is attached to the rear
case of every transfer case. The tag provides the
transfer case model number, assembly number, serial
number, and low range ratio.
The transfer case serial number also represents
the date of build.
OPERATION
OPERATING RANGE
Transfer case operating ranges are:
²2H (2-wheel drive)
²4H (4-wheel drive)
²4LO (4-wheel drive low range
The 2H range is for use on any road surface at any
time.
The 4H and 4LO ranges are for off road use only.
They are not for use on hard surface roads. The only
exception being when the road surface is covered by
ice and snow.
The low range reduction gear system is operative
in 4LO range only. This range is for extra pulling
power in off road situations. Low range reduction
ratio is 2.72:1.
SHIFT MECHANISM
The transfer case is operated by an adjustable floor
mounted shift linkage. The transfer case shift lever
is directly attached to the shift sector. The sector
operates the range and mode forks within the trans-
fer case.
A straight line shift pattern is used with a NEU-
TRAL detent. Lever range positions are imprinted in
the shift knob.
SHIFTING
The transfer case can be shifted between the 2H
and 4H operating ranges while the vehicle is in
motion. The vehicle must have the transmission
placed in NEUTRAL, or the clutch depressed in the
case of a manual transmission, and be moving less
than 2-3 MPH when shifting into and out of the 4L
operating range.
DIAGNOSIS AND TESTING - TRANSFER CASE -
NV271
Before beginning repair on a suspected transfer
case malfunction, check all other driveline compo-
nents beforehand.
The actual cause of a problem may be related to
such items as: front hubs, axles, propeller shafts,
wheels and tires, transmission, or clutch instead. If
all other driveline components are in good condition
and operating properly, refer to the Diagnosis Chart
for further information.
Fig. 2 Transfer Case - Rear View
1 - TRANSFER CASE
2 - IDENTIFICATION TAG
21 - 448 TRANSFER CASE - NV271DR
TRANSFER CASE - NV271 (Continued)

(10) Pull mainshaft assembly out of input gear,
mode sleeve, and case (Fig. 25).
(11) Remove mode fork, mode sleeve, and shift rail
as assembly (Fig. 26). Note which way the sleeve fits
in the fork (long side of sleeve goes to front or the
points on the sleeve teeth go to the rear of case).(12) Remove range fork and hub as an assembly
(Fig. 27). Note fork position for installation reference.
(13) Remove shift sector (Fig. 28).
Fig. 25 Remove Mainshaft Assembly
1 - FRONT CASE HALF
2 - MAINSHAFT ASSEMBLY
Fig. 26 Remove Mode Fork, Sleeve, and Shift Rail
Assembly
1 - SHIFT RAIL
2 - MODE FORK
3 - MODE SLEEVE
Fig. 27 Range Fork And Hub Removal
1 - RANGE HUB
2 - RANGE FORK
Fig. 28 Remove Shift Sector
1 - SHIFT SECTOR
21 - 456 TRANSFER CASE - NV271DR
TRANSFER CASE - NV271 (Continued)

(6) Remove front thrust plate (Fig. 37).
(7) Remove input gear (Fig. 38).
(8) Remove bottom tabbed thrust washer from low
range planetary (Fig. 39).
CLEANING
Clean the transfer case parts with a standard
parts cleaning solvent. Remove all traces of sealer
from the cases and retainers with a scraper and
3MŸ all purpose cleaner. Use compressed air toremove solvent residue from oil feed passages in the
case halves, retainers, gears, and shafts.
INSPECTION
MAINSHAFT/SPROCKET/HUB
Inspect the splines on the hub and shaft and the
teeth on the sprocket. 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.
INPUT GEAR AND PLANETARY CARRIER
Check the teeth on the gear (Fig. 40). 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. Check the pinion gear thrust wash-
ers on the pinon pins for damage. The carrier will
have to be replaced as an assembly if the body, pin-
ion 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.
Fig. 37 Remove Input Gear Thrust Plate
1 - INPUT GEAR
2 - THRUST PLATE
Fig. 38 Remove Input Gear From Planetary
1 - INPUT GEAR
2 - LOW RANGE PLANETARY
Fig. 39 Remove Bottom Input Gear Thrust Plate
1 - PLANETARY
2 - THRUST PLATE
DRTRANSFER CASE - NV271 21 - 459
TRANSFER CASE - NV271 (Continued)

SHIFT FORKS/HUBS/SLEEVES
Check condition of the shift forks and mode fork
shift rail (Fig. 41). Minor nicks on the shift rail can
be smoothed with 320-400 grit emery cloth.Inspect the shift fork wear pads (Fig. 42). The
mode and range fork pads are serviceable and can be
replaced if necessary.
Check both of the sleeves for wear or damage,
especially on the interior teeth. Replace the sleeves if
wear or damage is evident.
Fig. 40 Input Gear And Carrier Components
1 - PLANETARY CARRIER 4 - CARRIER LOCK RING
2 - REAR THRUST WASHER 5 - CARRIER LOCK RETAINING RING
3 - FRONT THRUST WASHER 6 - INPUT GEAR
Fig. 41 Shift forks
1 - RANGE FORK
2 - MODE FORK AND RAIL
3 - MODE SPRING
Fig. 42 Shift Fork And Wear Pad Locations
1 - RANGE FORK
2 - MODE FORK
3 - WEAR PADS (SERVICEABLE)
4 - WEAR PADS (SERVICEABLE)
21 - 460 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)

IDENTIFICATION
A circular ID tag is attached to the rear case of
each transfer case (Fig. 1). The ID tag provides the
transfer case model number, assembly number, serial
number, and low range ratio.
The transfer case serial number also represents
the date of build.
OPERATION
The input gear is splined to the transmission out-
put shaft. The input gear drives the mainshaft
through the planetary assembly and range sleeve.
The front output shaft is operated by a drive chain
that connects the shaft to a drive sprocket on the
mainshaft. The drive sprocket is engaged/disengaged
by the mode fork, which operates the mode sleeve
and hub. The sleeve and hub are not equipped with a
synchronizer mechanism for shifting.
DIAGNOSIS AND TESTING - TRANSFER CASE - NV243
DIAGNOSIS CHART
Condition Possible Cause Correction
Transfer case difficult to shift or will
not shift into desired range.1) Transfer case electronically
controlled shift system malfunction.1) Verify proper operation per the
appropriate diagnostic manual.
2) If vehicle was operated for an
extended period in 4HI mode on
dry surface, driveline torque load
may cause difficulty.2) Drive the vehicle in a straight line
and momentarily release the
accelerator. The transfer case can
then be shifted to the desired mode.
3) Insufficient or incorrect lubricant. 3) Drain and refill transfer case with
the correct quantity of MoparTAT F
+4, Automatic Transmission Fluid.
4) Internal transfer case
components binding, worn, or
damaged.4) Repair or replace components as
necessary.
Transfer case noisy in all drive
modes.1) Insufficient or incorrect lubricant. 1) Drain and refill transfer case with
the correct quantity of MoparTAT F
+4, type 9602, Automatic
Transmission Fluid.
2) Internal transfer case
components binding, worn, or
damaged.2) Repair or replace components as
necessary.
Fig. 1 Fill/Drain Plug And I.D. Tag Locations
1 - I.D. TAG
2 - FILL PLUG
3 - DRAIN PLUG
DRTRANSFER CASE - NV243 21 - 483
TRANSFER CASE - NV243 (Continued)

(4) Remove front output shaft from bearing in case
(Fig. 19).
(5) Pull mainshaft assembly out of input gear,
mode sleeve, and case (Fig. 20).(6) Remove mode fork, mode sleeve, and shift rail
as assembly (Fig. 21). Note which way the sleeve fits
in the fork (long side of sleeve goes to front).
(7) Remove range fork retaining ring.
(8) Remove range fork and hub as an assembly
(Fig. 22). Note fork position for installation reference.
Fig. 22 Range Fork And Hub Removal
1 - RANGE HUB
2 - RANGE FORK
Fig. 19 Remove Front Output Shaft
1 - FRONT CASE
2 - FRONT OUTPUT SHAFT
Fig. 20 Remove Mainshaft
1 - FRONT CASE
2 - MAINSHAFT
Fig. 21 Mode Fork And Sleeve Removal
1 - MODE SLEEVE
2 - MODE FORK AND RAIL
DRTRANSFER CASE - NV243 21 - 489
TRANSFER CASE - NV243 (Continued)