Transmission fluid DODGE RAM 2003 Service Repair Manual

OVERDRIVE CLUTCH
DESCRIPTION
The overdrive clutch (Fig. 132) is composed of the
pressure plate, clutch plates, holding discs, overdrive
piston retainer, piston, piston spacer, and snap-rings.
The overdrive clutch is the forwardmost component
in the transmission overdrive unit and is considered
a holding component. The overdrive piston retainer,
piston, and piston spacer are located on the rear of
the main transmission case.
NOTE: The number of discs and plates may vary
with each engine and vehicle combination.
OPERATION
To apply the clutch, pressure is applied between the
piston retainer and piston. The fluid pressure is pro-
vided by the oil pump, transferred through the control
valves and passageways, and enters the clutch through
passages at the lower rear portion of the valve body
area. With pressure applied between the piston retainer
and piston, the piston moves away from the piston
retainer and compresses the clutch pack. This action
applies the clutch pack, allowing torque to flow through
the intermediate shaft into the overdrive planetary gear
set. The overdrive clutch discs are attached to the over-
drive clutch hub while the overdrive clutch plates, reac-
tion plate, and pressure plate are lugged to the
overdrive housing. This allows the intermediate shaft totransfer the engine torque to the planetary gear and
overrunning clutch. This drives the planetary gear
inside the annulus, which is attached to the overdrive
clutch drum and output shaft, creating the desired gear
ratio. The waved snap-ring is used to cushion the appli-
cation of the clutch pack.
OVERDRIVE SWITCH
DESCRIPTION
The overdrive OFF (control) switch is located in
the shift lever arm (Fig. 133). The switch is a
momentary contact device that signals the PCM to
toggle current status of the overdrive function.
OPERATION
At key-on, overdrive operation is allowed. Pressing
the switch once causes the overdrive OFF mode to be
entered and the overdrive OFF switch lamp to be
illuminated. Pressing the switch a second time
causes normal overdrive operation to be restored and
the overdrive lamp to be turned off. The overdrive
OFF mode defaults to ON after the ignition switch is
cycled OFF and ON. The normal position for the con-
trol switch is the ON position. The switch must be in
this position to energize the solenoid and allow a 3-4
upshift. The control switch indicator light illuminates
only when the overdrive switch is turned to the OFF
position, or when illuminated by the transmission
control module.
Fig. 132 Overdrive Clutch
1 - REACTION PLATE 2 - PRESSURE PLATE
21 - 218 AUTOMATIC TRANSMISSION - 46REDR

OVERDRIVE UNIT
REMOVAL
(1) Shift transmission into PARK.
(2) Raise vehicle.
(3) Remove transfer case, if equipped.
(4) Mark propeller shaft universal joint(s) and axle
pinion yoke, or the companion flange and flange
yoke, for alignment reference at installation, if neces-
sary.
(5) Disconnect and remove the rear propeller shaft,
if necessary. (Refer to 3 - DIFFERENTIAL & DRIV-
ELINE/PROPELLER SHAFT/PROPELLER SHAFT -
REMOVAL)
(6) Remove transmission oil pan, remove gasket,
drain oil and reinstall pan.
(7) If overdrive unit had malfunctioned, or if fluid
is contaminated, remove entire transmission. If diag-
nosis indicated overdrive problems only, remove just
the overdrive unit.
(8) Support transmission with transmission jack.
(9) Remove bolts attaching overdrive unit to trans-
mission (Fig. 137).
CAUTION: Support the overdrive unit with a jack
before moving it rearward. This is necessary to pre-
vent damaging the intermediate shaft. Do not allow
the shaft to support the entire weight of the over-
drive unit.(10) Carefully work overdrive unit off intermediate
shaft. Do not tilt unit during removal. Keep it as
level as possible.
(11) If overdrive unit does not require service,
immediately insert Alignment Tool 6227-2 in splines
of planetary gear and overrunning clutch to prevent
splines from rotating out of alignment. If misalign-
ment occurs, overdrive unit will have to be disassem-
bled in order to realign splines.
(12) Remove and retain overdrive piston thrust
bearing. Bearing may remain on piston or in clutch
hub during removal.
(13) Position drain pan on workbench.
(14) Place overdrive unit over drain pan. Tilt unit
to drain residual fluid from case.
(15) Examine fluid for clutch material or metal
fragments. If fluid contains these items, overhaul will
be necessary.
(16) If overdrive unit does not require any service,
leave alignment tool in position. Tool will prevent
accidental misalignment of planetary gear and over-
running clutch splines.
DISASSEMBLY
(1) Remove transmission speed sensor and o-ring
seal from overdrive case (Fig. 138).
(2) Remove overdrive piston thrust bearing (Fig.
139).
Fig. 137 Overdrive Unit Bolts
1 - OVERDRIVE UNIT
2 - ATTACHING BOLTS (7)
Fig. 138 Transmission Speed Sensor
1 - SOCKET AND WRENCH
2 - SPEED SENSOR
3 - O-RING
21 - 220 AUTOMATIC TRANSMISSION - 46REDR

(10) Remove snap-ring that secures annulus gear
on output shaft (Fig. 164). Use two screwdrivers to
unseat and work snap-ring out of groove as shown.
(11) Remove annulus gear from output shaft (Fig.
165). Use rawhide or plastic mallet to tap gear off
shaft.
GEAR CASE AND PARK LOCK
(1) Remove locating ring from gear case.
(2) Remove park pawl shaft retaining bolt and
remove shaft, pawl and spring.
(3) Remove reaction plug snap-ring and remove
reaction plug.
(4) Remove output shaft seal.
CLEANING
Clean the geartrain and case components with sol-
vent. Dry all parts except the bearings with com-
pressed air. Allow bearings to air dry.
Do not use shop towels for wiping parts dry unless
the towels are made from a lint-free material. A suf-
ficient quantity of lint (from shop towels, cloths, rags,
etc.) could plug the transmission filter and fluid pas-
sages.
Discard the old case gasket and seals. Do not
attempt to salvage these parts. They are not reus-
able. Replace any of the overdrive unit snap-rings if
distorted or damaged.
Minor nicks or scratches on components can be
smoothed with crocus cloth. However, do not attempt
to reduce severe scoring on any components with
abrasive materials. Replace severely scored compo-
nents; do not try to salvage them.
INSPECTION
Check condition of the park lock components and
the overdrive case.
Check the bushings in the overdrive case. Replace
the bushings if severely scored or worn. Also replace
the case seal if loose, distorted, or damaged.
Examine the overdrive and direct clutch discs and
plates. Replace the discs if the facing is worn,
severely scored, or burned and flaking off. Replace
the clutch plates if worn, heavily scored, or cracked.
Check the lugs on the clutch plates for wear. The
plates should slide freely in the drum. Replace the
plates or drum if binding occurs.
Check condition of the annulus gear, direct clutch
hub, clutch drum and clutch spring. Replace the gear,
hub and drum if worn or damaged. Replace the
spring if collapsed, distorted, or cracked.
Be sure the splines and lugs on the gear, drum and
hub are in good condition. The clutch plates and
discs should slide freely in these components.
Inspect the thrust bearings and spring plate.
Replace the plate if worn or scored. Replace the bear-
ings if rough, noisy, brinnelled, or worn.
Inspect the planetary gear assembly and the sun
gear and bushings. If either the sun gear or the
bushings are damaged, replace the gear and bush-
ings as an assembly. The gear and bushings are not
serviced separately.
The planetary carrier and pinions must be in good
condition. Also be sure the pinion pins are secure and
in good condition. Replace the carrier if worn or dam-
aged.
Inspect the overrunning clutch and race. The race
surface should be smooth and free of scores. Replace
the overrunning clutch assembly or the race if either
assembly is worn or damaged in any way.
Fig. 164 Annulus Gear Snap-Ring Removal
1 - OUTPUT SHAFT
2 - ANNULUS GEAR
3 - SNAP-RING
Fig. 165 Annulus Gear Removal
1 - OUTPUT SHAFT
2 - ANNULUS GEAR
DRAUTOMATIC TRANSMISSION - 46RE 21 - 227
OVERDRIVE UNIT (Continued)

Replace the shaft pilot bushing and inner bushing
if damaged. Replace either shaft bearing if rough or
noisy. Replace the bearing snap-rings if distorted or
cracked.
Check the machined surfaces on the output shaft.
These surfaces should clean and smooth. Very minor
nicks or scratches can be smoothed with crocus cloth.
Replace the shaft if worn, scored or damaged in any
way.
Inspect the output shaft bushings. The small bush-
ing is the intermediate shaft pilot bushing. The large
bushing is the overrunning clutch hub bushing.
Replace either bushing if scored, pitted, cracked, or
worn.
ASSEMBLY
GEARTRAIN AND DIRECT CLUTCH
(1) Soak direct clutch and overdrive clutch discs in
MopartATF +4, Automatic Transmission fluid. Allow
discs to soak for 10-20 minutes.
(2) Install new pilot bushing and clutch hub bush-
ing in output shaft if necessary (Fig. 166). Lubricate
bushings with petroleum jelly, or transmission fluid.(3) Install annulus gear on output shaft, if
removed. Then install annulus gear retaining snap-
ring (Fig. 167).
(4) Align and install clutch drum on annulus gear
(Fig. 168). Be sure drum is engaged in annulus gear
lugs.
(5) Install clutch drum outer retaining ring (Fig.
168).
Fig. 166 Output Shaft Pilot Bushing
1 - OUTPUT SHAFT HUB
2 - OVERRUNNING CLUTCH HUB BUSHING
3 - INTERMEDIATE SHAFT PILOT BUSHING
Fig. 167 Annulus Gear Installation
1 - SNAP-RING
2 - OUTPUT SHAFT FRONT BEARING
3 - ANNULUS GEAR
Fig. 168 Clutch Drum And Outer Retaining Ring
Installation
1 - ANNULUS GEAR
2 - OUTER SNAP-RING
3 - CLUTCH DRUM
21 - 228 AUTOMATIC TRANSMISSION - 46REDR
OVERDRIVE UNIT (Continued)

(19) Install overdrive piston in overdrive piston
retainer by: aligning locating lugs on overdrive piston
to the two mating holes in retainer.
(a) Aligning locating lugs on overdrive piston to
the two mating holes in retainer.
(b) Lubricate overdrive piston seals with Mopart
Door Ease, or equivalent.
(c) Install piston over Seal Guide 8114-3 and
inside Guide Ring 8114-1.
(d) Push overdrive piston into position in
retainer.
(e) Verify that the locating lugs entered the lug
bores in the retainer.
PISTONS
DESCRIPTION
There are several sizes and types of pistons used in
an automatic transmission. Some pistons are used to
apply clutches, while others are used to apply bands.
They all have in common the fact that they are
round or circular in shape, located within a smooth
walled cylinder, which is closed at one end and con-
verts fluid pressure into mechanical movement. The
fluid pressure exerted on the piston is contained
within the system through the use of piston rings or
seals.
OPERATION
The principal which makes this operation possible
is known as Pascal's Law. Pascal's Law can be stated
as: ªPressure on a confined fluid is transmitted
equally in all directions and acts with equal force on
equal areas.º
PRESSURE
Pressure (Fig. 210) is nothing more than force
(lbs.) divided by area (in or ft.), or force per unit
area. Given a 100 lb. block and an area of 100 sq. in.
on the floor, the pressure exerted by the block is: 100
lbs. 100 in or 1 pound per square inch, or PSI as it is
commonly referred to.
PRESSURE ON A CONFINED FLUID
Pressure is exerted on a confined fluid (Fig. 211) by
applying a force to some given area in contact with
the fluid. A good example of this is a cylinder filled
with fluid and equipped with a piston that is closely
fitted to the cylinder wall. If a force is applied to the
piston, pressure will be developed in the fluid. Of
course, no pressure will be created if the fluid is not
confined. It will simply ªleakº past the piston. There
must be a resistance to flow in order to create pres-
sure. Piston sealing is extremely important in
hydraulic operation. Several kinds of seals are usedto accomplish this within a transmission. These
include but are not limited to O-rings, D-rings, lip
seals, sealing rings, or extremely close tolerances
between the piston and the cylinder wall. The force
exerted is downward (gravity), however, the principle
remains the same no matter which direction is taken.
The pressure created in the fluid is equal to the force
applied, divided by the piston area. If the force is 100
lbs., and the piston area is 10 sq. in., then the pres-
sure created equals 10 PSI. Another interpretation of
Pascal's Law is that regardless of container shape or
size, the pressure will be maintained throughout, as
long as the fluid is confined. In other words, the
pressure in the fluid is the same everywhere within
the container.
Fig. 210 Force and Pressure Relationship
Fig. 211 Pressure on a Confined Fluid
DRAUTOMATIC TRANSMISSION - 46RE 21 - 241
OVERRUNNING CLUTCH CAM/OVERDRIVE PISTON RETAINER (Continued)

FORCE MULTIPLICATION
Using the 10 PSI example used in the illustration
(Fig. 212), a force of 1000 lbs. can be moved with a
force of only 100 lbs. The secret of force multiplica-
tion in hydraulic systems is the total fluid contact
area employed. The illustration, (Fig. 212), shows an
area that is ten times larger than the original area.
The pressure created with the smaller 100 lb. input
is 10 PSI. The concept ªpressure is the same every-
whereº means that the pressure underneath the
larger piston is also 10 PSI. Pressure is equal to the
force applied divided by the contact area. Therefore,
by means of simple algebra, the output force may be
found. This concept is extremely important, as it is
also used in the design and operation of all shift
valves and limiting valves in the valve body, as well
as the pistons, of the transmission, which activate
the clutches and bands. It is nothing more than
using a difference of area to create a difference in
pressure to move an object.
PISTON TRAVEL
The relationship between hydraulic lever and a
mechanical lever is the same. With a mechanical
lever it's a weight-to-distance output rather than a
pressure-to-area output. Using the same forces and
areas as in the previous example, the smaller piston
(Fig. 213) has to move ten times the distance
required to move the larger piston one inch. There-
fore, for every inch the larger piston moves, the
smaller piston moves ten inches. This principle is
true in other instances also. A common garage floor
jack is a good example. To raise a car weighing 2000
lbs., an effort of only 100 lbs. may be required. For
every inch the car moves upward, the input piston at
the jack handle must move 20 inches downward.
PLANETARY GEARTRAIN/
OUTPUT SHAFT
DESCRIPTION
The planetary gearsets (Fig. 214) are designated as
the front, rear, and overdrive planetary gear assem-
blies and located in such order. A simple planetary
gearset consists of three main members:
Fig. 212 Force Multiplication
Fig. 213 Piston Travel
Fig. 214 Planetary Gearset
1 - ANNULUS GEAR
2 - SUN GEAR
3 - PLANET CARRIER
4 - PLANET PINIONS (4)
21 - 242 AUTOMATIC TRANSMISSION - 46REDR
PISTONS (Continued)

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
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 oversun gear and against rear side of driving shell (Fig.
223). Install rear snap-ring to secure sun gear and
thrust plate in driving shell.
(3) Install rear annulus gear on intermediate shaft
(Fig. 224).
(4) Install thrust plate in annulus gear (Fig. 225).
Be sure plate is seated on shaft splines and against
gear.
Fig. 223 Sun Gear Installation
1 - DRIVING SHELL
2 - SUN GEAR
3 - THRUST PLATE
4 - SUN GEAR REAR RETAINING RING
Fig. 224 Installing Rear Annulus Gear On
Intermediate Shaft
1 - REAR ANNULUS GEAR
2 - OUTPUT SHAFT
Fig. 225 Installing Rear Annulus Thrust Plate
1 - REAR ANNULUS GEAR
2 - THRUST PLATE
DRAUTOMATIC TRANSMISSION - 46RE 21 - 245
PLANETARY GEARTRAIN/OUTPUT SHAFT (Continued)

(5) Install rear planetary gear in rear annulus
gear (Fig. 226). Be sure planetary carrier is seated
against annulus gear.
(6) Install tabbed thrust washer on front face of
rear planetary gear (Fig. 227). 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. 228). 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. 229), be sure washer tabs are seated in tab slots
of driving shell. Use extra petroleum jelly to hold
washer in place if desired.
Fig. 226 Installing Rear Planetary Gear
1 - REAR ANNULUS GEAR
2 - REAR PLANETARY GEAR
Fig. 227 Installing Rear Planetary Thrust Washer
1 - REAR PLANETARY GEAR
2 - TABBED THRUST WASHER
Fig. 228 Installing Sun Gear And Driving Shell
1 - OUTPUT SHAFT
2 - DRIVING SHELL
3 - REAR PLANETARY GEAR
4 - OUTPUT SHAFT
5 - SUN GEAR
Fig. 229 Installing Driving Shell Thrust Washer
1 - TAB SLOTS (3)
2 - DRIVING SHELL
3 - TABBED THRUST WASHER
21 - 246 AUTOMATIC TRANSMISSION - 46REDR
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.
236).
(4) Remove the reaction plate, clutch discs, steel
plates, pressure plate, wave spring, spacer ring, and
piston spring (Fig. 236).
(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.
Fig. 235 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 - 46RE 21 - 249
REAR CLUTCH (Continued)

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.
ASSEMBLY
(1) Soak clutch discs in transmission fluid while
assembling other clutch parts.
(2) Install new seal rings on clutch retainer hub
and input shaft if necessary.
(a) Be sure clutch hub seal ring is fully seated in
groove and is not twisted.
Fig. 236 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)
21 - 250 AUTOMATIC TRANSMISSION - 46REDR
REAR CLUTCH (Continued)