1998 DODGE RAM 1500 air

OPERATION
REACTION PLANETARY GEARTRAIN
The reaction planetary carrier and reverse sun
gear of the reaction planetary geartrain are a single
component which is held by the 2C clutch when
required. The reaction annulus gear is a stand alone
component that can be driven by the reverse clutch
or held by the 4C clutch. The reaction sun gear is
driven by the overdrive clutch.
REVERSE PLANETARY GEARTRAIN
The reverse planetary geartrain is the middle of
the three planetary sets. The reverse planetary car-
rier can be driven by the overdrive clutch as
required. The reverse planetary carrier is also
splined to the input annulus gear, which can be held
by the low/reverse clutch. The reverse planetary
annulus, input planetary carrier, and output shaft
are all one piece.
INPUT PLANETARY GEARTRAIN
The input sun gear of the input planetary
geartrain is driven by the underdrive clutch.
DISASSEMBLY
(1) Remove the snap-ring holding the input annu-
lus into the input carrier (Fig. 116).
(2) Remove the input annulus from the input car-
rier (Fig. 116).
(3) Remove the number 9 bearing from the reverse
planetary carrier. Note that this planetary carrier
has four pinion gears.
(4) Remove the reverse planetary gear carrier (Fig.
116).
(5) Remove the number 10 bearing from the input
sun gear (Fig. 116).
(6) Remove the input sun gear from the input car-
rier (Fig. 116).
(7) Remove the number 11 bearing from the input
carrier (Fig. 116).
CLEANING
Clean the planetary components in solvent and dry
them with compressed air.
Fig. 115 Reverse/Input Planetary Geartrain
1 - SNAP-RING 5 - INPUT PLANETARY CARRIER
2 - BEARING NUMBER 10 6 - INPUT SUN GEAR
3 - BEARING NUMBER 11 7 - REVERSE PLANETARY CARRIER
4 - INPUT ANNULUS
21 - 396 AUTOMATIC TRANSMISSION - 45RFE/545RFEDR
PLANETARY GEARTRAIN (Continued)

A solenoid can also be described by the method by
which it is controlled. Some of the possibilities
include variable force, pulse-width modulated, con-
stant ON, or duty cycle. The variable force and pulse-
width modulated versions utilize similar methods to
control the current flow through the solenoid to posi-
tion the solenoid plunger at a desired position some-
where between full ON and full OFF. The constant
ON and duty cycled versions control the voltage
across the solenoid to allow either full flow or no flow
through the solenoid's valve.
OPERATION
When an electrical current is applied to the sole-
noid coil, a magnetic field is created which produces
an attraction to the plunger, causing the plunger to
move and work against the spring pressure and the
load applied by the fluid the valve is controlling. The
plunger is normally directly attached to the valve
which it is to operate. When the current is removed
from the coil, the attraction is removed and the
plunger will return to its original position due to
spring pressure.
The plunger is made of a conductive material and
accomplishes this movement by providing a path for
the magnetic field to flow. By keeping the air gap
between the plunger and the coil to the minimum
necessary to allow free movement of the plunger, the
magnetic field is maximized.
TORQUE CONVERTER
DESCRIPTION
The torque converter (Fig. 117) is a hydraulic
device that couples the engine crankshaft to the
transmission. The torque converter consists of an
outer shell with an internal turbine, a stator, anoverrunning clutch, an impeller and an electronically
applied converter clutch. The converter clutch pro-
vides reduced engine speed and greater fuel economy
when engaged. Clutch engagement also provides
reduced transmission fluid temperatures. The torque
converter hub drives the transmission oil (fluid)
pump and contains an o-ring seal to better control oil
flow.
The torque converter is a sealed, welded unit that
is not repairable and is serviced as an assembly.
CAUTION: The torque converter must be replaced if
a transmission failure resulted in large amounts of
metal or fiber contamination in the fluid.
Fig. 117 Torque Converter Assembly
1 - TURBINE ASSEMBLY
2-STATOR
3 - CONVERTER HUB
4 - O-RING
5 - IMPELLER ASSEMBLY
6 - CONVERTER CLUTCH PISTON
7 - TURBINE HUB
DRAUTOMATIC TRANSMISSION - 45RFE/545RFE 21 - 399
SOLENOIDS (Continued)

(11) Remove the transfer plate from the valve
body. Note the location of all check balls (Fig. 137).
(12) Remove the check balls from the valve body.
(13) Remove the retainers securing the solenoid
switch valve, manual valve, and the low/reverse
switch valve into the valve body and remove the
associated valve and spring. Tag each valve and
spring combination with location information to aid
in assembly. (Fig. 138)
CLEANING
Clean the valve housings, valves, plugs, springs,
and separator plates with a standard parts cleaning
solution only. Do not use gasoline, kerosene, or any
type of caustic solution. (Fig. 139)
Do not immerse any of the electrical components in
cleaning solution. Clean the electrical components by
wiping them off with dry shop towels only.
Dry all except the electrical parts with compressed
air. Make sure all passages are clean and free from
obstructions.Do not use rags or shop towels to
dry or wipe off valve body components. Lint
from these materials can stick to valve body
parts, interfere with valve operation, and clog
filters and fluid passages.
Fig. 137 Check Ball Locations
Fig. 138 Valve Body Components
1 - SOLENOID SWITCH VALVE
2 - MANUAL VALVE
3 - LOW REVERSE SWITCH VALVE
4 - LOW REVERSE ACCUMULATOR
5 - 2ND CLUTCH ACCUMULATOR
6 - UNDERDRIVE ACCUMULATOR
7 - OVERDRIVE ACCUMULATOR
8 - 4TH CLUTCH ACCUMULATOR
9 - CHECK BALLS (7)
21 - 412 AUTOMATIC TRANSMISSION - 45RFE/545RFEDR
VALVE BODY (Continued)

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 sectoroperates 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 -
NV241 GENII
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.
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.
Fig. 2 Transfer Case - Rear View
1 - TRANSFER CASE
2 - IDENTIFICATION TAG
21 - 416 TRANSFER CASE - NV241 GENIIDR
TRANSFER CASE - NV241 GENII (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 transfer case position
sensor connector.
(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) Mark front and rear propeller shafts for assem-
bly reference.(9) Remove front and rear propeller shafts. (Refer
to 3 - DIFFERENTIAL & DRIVELINE/PROPELLER
SHAFT/PROPELLER SHAFT - REMOVAL)
(10) Support transfer case with suitable jack.
Secure transfer case to jack with safety chains.
(11) Remove nuts attaching transfer case to trans-
mission.
(12) Move transfer case assembly rearward until
free of transmission output shaft.
(13) 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.
DRTRANSFER CASE - NV241 GENII 21 - 417
TRANSFER CASE - NV241 GENII (Continued)

(2) Remove retainer (Fig. 36).
(3) Remove front tabbed thrust washer (Fig. 37).
(4) Remove input gear (Fig. 38).
(5) Remove rear tabbed thrust washer from low
range gear (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 to
remove 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.
Fig. 36 Input Gear Retainer Removal
1 - INPUT GEAR
2 - LOW RANGE GEAR
3 - RETAINER
Fig. 37 Front Tabbed Thrust Washer Removal
1 - FRONT TABBED THRUST WASHER
Fig. 38 Input Gear Removal
1 - INPUT GEAR
2 - LOW RANGE GEAR
Fig. 39 Rear Tabbed Thrust Washer Removal
1 - LOW RANGE GEAR
2 - REAR TABBED THRUST WASHER
21 - 426 TRANSFER CASE - NV241 GENIIDR
TRANSFER CASE - NV241 GENII (Continued)

DRIVE CHAIN
Examine the drive chain and shaft bearings.
replace the chain if stretched, distorted, or if any of
the links bind. Replace the bearings if rough, or
noisy.
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. 43)
FRONT CASE AND REAR CASE
Inspect the cases for wear and damage.
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) Remove the input shaft bearing (Fig. 44) from
the front case with suitable snap-ring pliers.
(2) Transfer the retaining ring to the new bearing
if necessary and install the bearing into the front
case.
Fig. 42 Shift Fork And Wear Pad Locations
1 - RANGE FORK
2 - MODE FORK
3 - WEAR PADS (SERVICEABLE)
4 - WEAR PADS (SERVICEABLE)
Fig. 43 Low Range Annulus Gear
1 - FRONT CASE
2 - LOW RANGE ANNULUS GEAR
Fig. 44 Remove Input Gear Bearing
1 - INPUT GEAR BEARING
2 - FRONT CASE
21 - 428 TRANSFER CASE - NV241 GENIIDR
TRANSFER CASE - NV241 GENII (Continued)

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)