vin DODGE RAM 1500 1998 2.G Workshop Manual

DISASSEMBLY
(1) Remove planetary snap-ring from intermediate
shaft (Fig. 193). Discard snap-ring as it is not reus-
able.
(2) Remove front planetary gear and front annulus
gear as assembly (Fig. 194).
(3) Remove front planetary gear and thrust
washer from front annulus gear (Fig. 195). Note
thrust washer position for assembly reference.
(4) Remove tabbed thrust washer from driving
shell (Fig. 196). Note washer position for assembly
reference.
Fig. 193 Removing Planetary Snap-Ring
1 - PLANETARY SNAP-RING
Fig. 194 Removing Front Planetary And Annulus
Gears
1 - DRIVING SHELL
2 - FRONT ANNULUS GEAR
3 - FRONT PLANETARY GEAR
Fig. 195 Disassembling Front Planetary And
Annulus Gears
1 - FRONT PLANETARY GEAR
2 - TABBED THRUST WASHER
3 - FRONT ANNULUS GEAR
4 - TORLON BUSHING
Fig. 196 Driving Shell Thrust Washer Removal
1 - DRIVING SHELL
2 - TABBED THRUST WASHER
3 - SUN GEAR
21 - 242 AUTOMATIC TRANSMISSION - 48REDR
PLANETARY GEARTRAIN/OUTPUT SHAFT (Continued)

(5) Remove sun gear and driving shell as assembly
(Fig. 197).
(6) Remove tabbed thrust washer from rear plane-
tary gear (Fig. 198). Note washer position on gear for
assembly reference.
(7) Remove rear planetary gear and rear annulus
gear from intermediate shaft (Fig. 199).
(8) Remove thrust washer from rear planetary
gear (Fig. 200).
INSPECTION
Inspect the planetary gear sets and annulus gears.
The planetary pinions, shafts, washers, and retaining
pins are serviceable. However, if a pinion carrier is
damaged, the entire planetary gear set must be
replaced as an assembly.Replace the annulus gears if the teeth are chipped,
broken, or worn, or the gear is cracked. Replace the
planetary thrust plates and the tabbed thrust wash-
ers if cracked, scored or worn.
Inspect the machined surfaces of the intermediate
shaft. Be sure the oil passages are open and clear.
Replace the shaft if scored, pitted, or damaged.
Inspect the sun gear and driving shell. If either
component is worn or damaged, remove the sun gear
rear retaining ring and separate the sun gear and
thrust plate from the driving shell. Then replace the
necessary component.
Replace the sun gear as an assembly if the gear
teeth are chipped or worn. Also replace the gear as
an assembly if the bushings are scored or worn. The
sun gear bushings are not serviceable. Replace the
Fig. 197 Sun Gear And Driving Shell Removal
1 - INTERMEDIATE SHAFT
2 - DRIVING SHELL
3 - SUN GEAR
Fig. 198 Rear Planetary Thrust Washer Removal
1 - SUN GEAR
2 - REAR PLANETARY THRUST WASHER
3 - DRIVING SHELL
Fig. 199 Rear Planetary And Annulus Gear Removal
1 - INTERMEDIATE SHAFT
2 - REAR ANNULUS GEAR
3 - REAR PLANETARY GEAR
Fig. 200 Rear Annulus Thrust Washer Removal
1 - REAR ANNULUS GEAR
2 - THRUST WASHER
DRAUTOMATIC TRANSMISSION - 48RE 21 - 243
PLANETARY GEARTRAIN/OUTPUT SHAFT (Continued)

thrust plate if worn, or severely scored. Replace the
driving shell if distorted, cracked, or damaged in any
way.
Replace all snap-rings during geartrain assembly.
Reusing snap-rings is not recommended.
ASSEMBLY
(1) Lubricate sun gear and planetary gears with
transmission fluid during assembly. Use petroleum
jelly to lubricate intermediate shaft bushing surfaces,
thrust washers and thrust plates and to hold these
parts in place during assembly.
(2) Install front snap-ring on sun gear and install
gear in driving shell. Then install thrust plate over
sun gear and against rear side of driving shell (Fig.
201). Install rear snap-ring to secure sun gear and
thrust plate in driving shell. Note that the large ID
chamfer on the sun gear goes forward.
(3) Install rear annulus gear on intermediate shaft
(Fig. 202).
(4) Install thrust washer to rear planetary gear
(Fig. 203) using petroleum jelly. Be sure washer is
seated against corner witht teh tabs completely in
the locating holes.
(5) Install rear planetary gear in rear annulus
gear (Fig. 204). Be sure planetary carrier is seated
against annulus gear.
Fig. 202 Installing Rear Annulus Gear On
Intermediate Shaft
1 - REAR ANNULUS GEAR
2 - OUTPUT SHAFT
Fig. 203 Installing Rear Annulus Thrust Washer
1 - REAR ANNULUS GEAR
2 - THRUST WASHER
Fig. 204 Installing Rear Planetary Gear
1 - REAR ANNULUS GEAR
2 - REAR PLANETARY GEAR
Fig. 201 Sun Gear Installation
1 - DRIVING SHELL
2 - SUN GEAR
3 - THRUST PLATE
4 - SUN GEAR REAR RETAINING RING
21 - 244 AUTOMATIC TRANSMISSION - 48REDR
PLANETARY GEARTRAIN/OUTPUT SHAFT (Continued)

(6) Install tabbed thrust washer on front face of
rear planetary gear (Fig. 205). Seat washer tabs in
matching slots in face of gear carrier. Use extra
petroleum jelly to hold washer in place if desired.
(7) Lubricate sun gear bushings with petroleum
jelly or transmission fluid.
(8) Install sun gear and driving shell on interme-
diate shaft (Fig. 206). Seat shell against rear plane-
tary gear. Verify that thrust washer on planetary
gear was not displaced during installation.
(9) Install tabbed thrust washer in driving shell
(Fig. 207), be sure washer tabs are seated in tab slots
of driving shell. Use extra petroleum jelly to hold
washer in place if desired.
(10) Install tabbed thrust washer on front plane-
tary gear (Fig. 208). Seat washer tabs in matchingslots in face of gear carrier. Use extra petroleum jelly
to hold washer in place if desired.
(11) Install the torlon bushing onto the front plan-
etary carrier hub.
Fig. 205 Installing Rear Planetary Thrust Washer
1 - REAR PLANETARY GEAR
2 - TABBED THRUST WASHER
Fig. 206 Installing Sun Gear And Driving Shell
1 - OUTPUT SHAFT
2 - DRIVING SHELL
3 - REAR PLANETARY GEAR
4 - OUTPUT SHAFT
5 - SUN GEAR
Fig. 207 Installing Driving Shell Thrust Washer
1 - TAB SLOTS (3)
2 - DRIVING SHELL
3 - TABBED THRUST WASHER
Fig. 208 Installing Thrust Washer On Front
Planetary Gear
1 - TABBED THRUST WASHER
2 - FRONT PLANETARY GEAR
DRAUTOMATIC TRANSMISSION - 48RE 21 - 245
PLANETARY GEARTRAIN/OUTPUT SHAFT (Continued)

(12) Install front annulus gear over and onto front
planetary gear (Fig. 209). Be sure gears are fully
meshed and seated.
(13) Install front planetary and annulus gear
assembly (Fig. 210). Hold gears together and slide
them onto shaft. Be sure planetary pinions are
seated on sun gear and that planetary carrier is
seated on intermediate shaft.
(14) Place geartrain in upright position. Rotate
gears to be sure all components are seated and prop-
erly assembled. Snap-ring groove at forward end of
intermediate shaft will be completely exposed when
components are assembled correctly.
(15) Install new planetary snap-ring in groove at
end of intermediate shaft (Fig. 211).
(16) Turn planetary geartrain over. Position wood
block under front end of intermediate shaft and sup-
port geartrain on shaft. Be sure all geartrain parts
have moved forward against planetary snap-ring.
This is important for accurate end play check.
Fig. 209 Assembling Front Planetary And
Annulus Gears
1 - FRONT ANNULUS GEAR
2 - FRONT PLANETARY GEAR
Fig. 210 Installing Front Planetary And Annulus
Gear Assembly
1 - DRIVING SHELL
2 - ASSEMBLED FRONT PLANETARY AND ANNULUS GEARS
Fig. 211 Installing Planetary Snap
1 - SNAP-RING PLIERS
2 - PLANETARY SNAP-RING
21 - 246 AUTOMATIC TRANSMISSION - 48REDR
PLANETARY GEARTRAIN/OUTPUT SHAFT (Continued)

(17) Check planetary geartrain end play with
feeler gauge (Fig. 212). Insert gauge between rear
annulus gear and shoulder on intermediate shaft as
shown. End play should be 0.15 to 1.22 mm (0.006 to
0.048 in.).
(18) If end play is incorrect, install thinner/thicker
planetary snap-ring as needed.
REAR CLUTCH
DESCRIPTION
The rear clutch assembly (Fig. 213) is composed of
the rear clutch retainer, pressure plate, clutch plates,
driving discs, piston, Belleville spring, and snap-
rings. The Belleville spring acts as a lever to multi-
ply the force applied on to it by the apply piston. The
increased apply force on the rear clutch pack, in com-
parison to the front clutch pack, is needed to hold
against the greater torque load imposed onto the rear
pack. The rear clutch is directly behind the front
clutch and is considered a driving component.NOTE: The number of discs and plates may vary
with each engine and vehicle combination.
Fig. 212 Checking Planetary Geartrain End Play
1 - OUTPUT SHAFT
2 - REAR ANNULUS GEAR
3 - FEELER GAUGE
Fig. 213 Rear Clutch Components
1 - REAR CLUTCH RETAINER 11 - REACTION PLATE
2 - TORLONŸ SEAL RINGS 12 - CLUTCH PLATES
3 - INPUT SHAFT 13 - WAVE SPRING
4 - PISTON RETAINER 14 - SPACER RING
5 - OUTPUT SHAFT THRUST WASHER 15 - PISTON
6 - INNER PISTON SEAL 16 - OUTER PISTON SEAL
7 - PISTON SPRING 17 - REAR SEAL RING
8 - PRESSURE PLATE 18 - FIBER THRUST WASHER
9 - CLUTCH DISCS 19 - RETAINING RING
10 - SNAP-RING (SELECTIVE)
DRAUTOMATIC TRANSMISSION - 48RE 21 - 247
PLANETARY GEARTRAIN/OUTPUT SHAFT (Continued)

OPERATION
To apply the clutch, pressure is applied between
the clutch retainer and piston. The fluid pressure is
provided by the oil pump, transferred through the
control valves and passageways, and enters the
clutch through the hub of the reaction shaft support.
With pressure applied between the clutch retainer
and piston, the piston moves away from the clutch
retainer and compresses the clutch pack. This action
applies the clutch pack, allowing torque to flow
through the input shaft into the driving discs, and
into the clutch plates and pressure plate that are
lugged to the clutch retainer. The waved spring is
used to cushion the application of the clutch pack.
The snap-ring is selective and used to adjust clutch
pack clearance.
When pressure is released from the piston, the
spring returns the piston to its fully released position
and disengages the clutch. The release spring also
helps to cushion the application of the clutch assem-
bly. When the clutch is in the process of being
released by the release spring, fluid flows through a
vent and one-way ball-check-valve located in the pis-
ton. The check-valve is needed to eliminate the pos-
sibility of plate drag caused by centrifugal force
acting on the residual fluid trapped in the clutch pis-
ton retainer.
DISASSEMBLY
(1) Remove fiber thrust washer from forward side
of clutch retainer.
(2) Remove input shaft front and rear seal rings.
(3) Remove selective clutch pack snap-ring (Fig.
214).
(4) Remove the reaction plate, clutch discs, steel
plates, pressure plate, wave spring, spacer ring, and
piston spring (Fig. 214).
(5) Remove clutch piston with rotating motion.
(6) Remove and discard piston seals.
(7) Remove input shaft retaining ring. It may be
necessary to press the input shaft in slightly to
relieve tension on the retaining ring
(8) Press input shaft out of retainer with shop
press and suitable size press tool. Use a suitably
sized press tool to support the retainer as close to the
input shaft as possible.
CLEANING
Clean the clutch components with solvent and dry
them with compressed air. Do not use rags or shop
towels to dry any of the clutch parts. Lint from such
materials will adhere to component surfaces and
could restrict or block fluid passages after assembly.
INSPECTION
Replace the clutch discs if warped, worn, scored,
burned/charred, the lugs are damaged, or if the fac-
ing is flaking off. Replace the top and bottom pres-
sure plates if scored, warped, or cracked. Be sure the
driving lugs on the pressure and clutch plates are
also in good condition. The lugs must not be bent,
cracked or damaged in any way.
Replace the piston spring and wave spring if either
part is distorted, warped or broken.
Check the lug grooves in the clutch retainer. The
clutch and pressure plates should slide freely in the
slots. Replace the retainer if the grooves are worn or
damaged. Also check action of the check balls in the
retainer and piston. Each check ball must move
freely and not stick.
Replace the retainer bushing if worn, scored, or
doubt exists about bushing condition.
Inspect the piston and retainer seal surfaces for
nicks or scratches. Minor scratches can be removed
with crocus cloth. However, replace the piston and/or
retainer if the seal surfaces are seriously scored.
Check condition of the fiber thrust washer and
metal output shaft thrust washer. Replace either
washer if worn or damaged.
Check condition of the seal rings on the input shaft
and clutch retainer hub. Replace the seal rings only
if worn, distorted, or damaged. The input shaft front
seal ring is teflon with chamfered ends. The rear ring
is metal with interlocking ends.
Check the input shaft for wear, or damage. Replace
the shaft if worn, scored or damaged in any way.
21 - 248 AUTOMATIC TRANSMISSION - 48REDR
REAR CLUTCH (Continued)

IMPELLER
The impeller (Fig. 228) is an integral part of the
converter housing. The impeller consists of curved
blades placed radially along the inside of the housing
on the transmission side of the converter. As the con-
verter housing is rotated by the engine, so is the
impeller, because they are one and the same and are
the driving members of the system.
Fig. 228 Impeller
1 - ENGINE FLEXPLATE 4 - ENGINE ROTATION
2 - OIL FLOW FROM IMPELLER SECTION INTO TURBINE
SECTION5 - ENGINE ROTATION
3 - IMPELLER VANES AND COVER ARE INTEGRAL
21 - 256 AUTOMATIC TRANSMISSION - 48REDR
TORQUE CONVERTER (Continued)

OPERATION
The converter impeller (Fig. 233) (driving member),
which is integral to the converter housing and bolted
to the engine drive plate, rotates at engine speed.
The converter turbine (driven member), which reacts
from fluid pressure generated by the impeller, rotates
and turns the transmission input shaft.
TURBINE
As the fluid that was put into motion by the impel-
ler blades strikes the blades of the turbine, some of
the energy and rotational force is transferred into the
turbine and the input shaft. This causes both of them
(turbine and input shaft) to rotate in a clockwise
direction following the impeller. As the fluid is leav-
ing the trailing edges of the turbine's blades it con-
tinues in a ªhinderingº direction back toward the
impeller. If the fluid is not redirected before it strikes
the impeller, it will strike the impeller in a direction
that would tend to slow it down.
Fig. 233 Torque Converter Fluid Operation
1 - APPLY PRESSURE 3 - RELEASE PRESSURE
2 - THE PISTON MOVES SLIGHTLY FORWARD 4 - THE PISTON MOVES SLIGHTLY REARWARD
DRAUTOMATIC TRANSMISSION - 48RE 21 - 259
TORQUE CONVERTER (Continued)

STATOR
Torque multiplication is achieved by locking the
stator's over-running clutch to its shaft (Fig. 234).
Under stall conditions the turbine is stationary and
the oil leaving the turbine blades strikes the face of
the stator blades and tries to rotate them in a coun-
terclockwise direction. When this happens the over-
running clutch of the stator locks and holds the
stator from rotating. With the stator locked, the oil
strikes the stator blades and is redirected into a
ªhelpingº direction before it enters the impeller. This
circulation of oil from impeller to turbine, turbine to
stator, and stator to impeller, can produce a maxi-
mum torque multiplication of about 1.75:1. As the
turbine begins to match the speed of the impeller, the
fluid that was hitting the stator in such as way as to
cause it to lock-up is no longer doing so. In this con-
dition of operation, the stator begins to free wheel
and the converter acts as a fluid coupling.
TORQUE CONVERTER CLUTCH (TCC)
The torque converter clutch is hydraulically
applied or released when fluid is feed or vented from
the hydraulic circuit by the torque converter control
(TCC) solenoid on the valve body. The torque con-
verter clutch is controlled by the Powertrain Control
Module (PCM). The torque converter clutch engages
in FOURTH gear, and in THIRD gear under various
conditions, such as when the O/D switch is OFF, orwhen the vehicle is cruising on a level surface after
the vehicle has warmed up. The torque converter
clutch can also be engaged in the MANUAL SEC-
OND gear position if high transmission temperatures
are sensed by the PCM. The torque converter clutch
may disengage momentarily when an increase in
engine load is sensed by the PCM, such as when the
vehicle begins to go uphill or the throttle pressure is
increased.
REMOVAL
(1) Remove transmission and torque converter
from vehicle.
(2) Place a suitable drain pan under the converter
housing end of the transmission.
CAUTION: Verify that transmission is secure on the
lifting device or work surface, the center of gravity
of the transmission will shift when the torque con-
verter is removed creating an unstable condition.
The torque converter is a heavy unit. Use caution
when separating the torque converter from the
transmission.
(3) Pull the torque converter forward until the cen-
ter hub clears the oil pump seal.
(4) Separate the torque converter from the trans-
mission.
INSTALLATION
Check converter hub and drive notches for sharp
edges, burrs, scratches, or nicks. Polish the hub and
notches with 320/400 grit paper or crocus cloth if nec-
essary. The hub must be smooth to avoid damaging
the pump seal at installation.
(1) Lubricate oil pump seal lip with transmission
fluid.
(2) Place torque converter in position on transmis-
sion.
CAUTION: Do not damage oil pump seal or bushing
while inserting torque converter into the front of the
transmission.
(3) Align torque converter to oil pump seal open-
ing.
(4) Insert torque converter hub into oil pump.
(5) While pushing torque converter inward, rotate
converter until converter is fully seated in the oil
pump gears.
Fig. 234 Stator Operation
1 - DIRECTION STATOR WILL FREE WHEEL DUE TO OIL
PUSHING ON BACKSIDE OF VANES
2 - FRONT OF ENGINE
3 - INCREASED ANGLE AS OIL STRIKES VANES
4 - DIRECTION STATOR IS LOCKED UP DUE TO OIL PUSHING
AGAINST STATOR VANES
21 - 260 AUTOMATIC TRANSMISSION - 48REDR
TORQUE CONVERTER (Continued)