torque DODGE RAM 2003 Service Repair Manual

REAR BAND
The transmission oil pan must be removed for
access to the rear band adjusting screw.
(1) Raise vehicle.
(2) Remove transmission oil pan and drain fluid.
(3) Loosen band adjusting screw locknut 5-6 turns.
Be sure adjusting screw turns freely in lever.
(4) Tighten adjusting screw to 8 N´m (72 in. lbs.)
torque (Fig. 75).
(5) Back off adjusting screw 3 turns.
(6) Hold adjusting screw in place and tighten lock-
nut to 34 N´m (25 ft. lbs.) torque.
(7) Position new gasket on oil pan and install pan
on transmission. Tighten pan bolts to 17 N´m (13 ft.
lbs.) torque.
(8) Lower vehicle and refill transmission with
MopartATF +4, Automatic Transmission fluid.
BRAKE TRANSMISSION SHIFT
INTERLOCK SYSTEM
DESCRIPTION
The Brake Transmission Shifter Interlock (BTSI)
(Fig. 76), is a solenoid operated system. It consists of
a solenoid permanently mounted on the gearshift
cable.
OPERATION
The system locks the shifter into the PARK posi-
tion. The interlock system is engaged whenever the
ignition switch is in the LOCK or ACCESSORY posi-
tion. An additional electrically activated feature will
prevent shifting out of the PARK position unless the
brake pedal is depressed approximately one-half an
inch. A magnetic holding device in line with the park
lock cable is energized when the ignition is in the
RUN position. When the key is in the RUN position
and the brake pedal is depressed, the shifter isunlocked and will move into any position. The inter-
lock system also prevents the ignition switch from
being turned to the LOCK or ACCESSORY position,
unless the shifter is fully locked into the PARK posi-
tion.
DIAGNOSIS AND TESTING - BRAKE
TRANSMISSION SHIFT INTERLOCK
(1) Verify that the key can only be removed in the
PARK position
(2) When the shift lever is in PARK And the shift
handle pushbutton is in the ªOUTº position, the igni-
tion key cylinder should rotate freely from OFF to
LOCK. When the shifter is in any other gear or neu-
tral position, the ignition key cylinder should not
rotate to the LOCK position.
(3) Shifting out of PARK should not be possible
when the ignition key cylinder is in the OFF posi-
tion.
(4) Shifting out of PARK should not be possible
while applying normal pushbutton force and ignition
key cylinder is in the RUN or START positions
unless the foot brake pedal is depressed approxi-
mately 1/2 inch (12mm).
(5) Shifting out of PARK should not be possible
when the ignition key cylinder is in the ACCESSORY
or LOCK positions.
(6) Shifting between any gears, NEUTRAL or into
PARK may be done without depressing foot brake
pedal with ignition switch in RUN or START posi-
tions.
Fig. 75 Rear Band Adjustment Screw Location
1 - LOW-REVERSE BAND ADJUSTMENT
Fig. 76 Brake Transmission Interlock Mechanism
1 - STEERING COLUMN
2 - GEARSHIFT CABLE
3 - GEARSHIFT CABLE LOCK TAB
4 - BTSI SOLENOID LOCK TAB
5 - BTSI CONNECTOR
DRAUTOMATIC TRANSMISSION - 48RE 21 - 375
BANDS (Continued)

FLUID AND FILTER
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - EFFECTS OF
INCORRECT FLUID LEVEL
A low fluid level allows the pump to take in air
along with the fluid. Air in the fluid will cause fluid
pressures to be low and develop slower than normal.
If the transmission is overfilled, the gears churn the
fluid into foam. This aerates the fluid and causing
the same conditions occurring with a low level. In
either case, air bubbles cause fluid overheating, oxi-
dation and varnish buildup which interferes with
valve and clutch operation. Foaming also causes fluid
expansion which can result in fluid overflow from the
transmission vent or fill tube. Fluid overflow can eas-
ily be mistaken for a leak if inspection is not careful.
DIAGNOSIS AND TESTING - CAUSES OF
BURNT FLUID
Burnt, discolored fluid is a result of overheating
which has two primary causes.
(1) A result of restricted fluid flow through the
main and/or auxiliary cooler. This condition is usu-
ally the result of a faulty or improperly installed
drainback valve, a damaged main cooler, or severe
restrictions in the coolers and lines caused by debris
or kinked lines.
(2) Heavy duty operation with a vehicle not prop-
erly equipped for this type of operation. Trailer tow-
ing or similar high load operation will overheat the
transmission fluid if the vehicle is improperly
equipped. Such vehicles should have an auxiliary
transmission fluid cooler, a heavy duty cooling sys-
tem, and the engine/axle ratio combination needed to
handle heavy loads.
DIAGNOSIS AND TESTING - FLUID
CONTAMINATION
Transmission fluid contamination is generally a
result of:
²adding incorrect fluid
²failure to clean dipstick and fill tube when
checking level
²engine coolant entering the fluid
²internal failure that generates debris
²overheat that generates sludge (fluid break-
down)
²failure to replace contaminated converter after
repair
The use of non-recommended fluids can result in
transmission failure. The usual results are erratic
shifts, slippage, abnormal wear and eventual failuredue to fluid breakdown and sludge formation. Avoid
this condition by using recommended fluids only.
The dipstick cap and fill tube should be wiped
clean before checking fluid level. Dirt, grease and
other foreign material on the cap and tube could fall
into the tube if not removed beforehand. Take the
time to wipe the cap and tube clean before withdraw-
ing the dipstick.
Engine coolant in the transmission fluid is gener-
ally caused by a cooler malfunction. The only remedy
is to replace the radiator as the cooler in the radiator
is not a serviceable part. If coolant has circulated
through the transmission, an overhaul is necessary.
The torque converter should be replaced whenever
a failure generates sludge and debris. This is neces-
sary because normal converter flushing procedures
will not remove all contaminants.
STANDARD PROCEDURE
STANDARD PROCEDURE - FLUID LEVEL
CHECK
Low fluid level can cause a variety of conditions
because it allows the pump to take in air along with
the fluid. As in any hydraulic system, air bubbles
make the fluid spongy, therefore, pressures will be
low and build up slowly.
Improper filling can also raise the fluid level too
high. When the transmssion has too much fluid, the
geartrain churns up foam and cause the same condi-
tions which occur with a low fluid level.
In either case, air bubbles can cause overheating
and/or fluid oxidation, and varnishing. This can
interfere with normal valve, clutch, and accumulator
operation. Foaming can also result in fluid escaping
from the transmission vent where it may be mis-
taken for a leak.
After the fluid has been checked, seat the dipstick
fully to seal out water and dirt.
The transmission has a dipstick to check oil level.
It is located on the right side of the engine. Be sure
to wipe all dirt from dipstick handle before removing.
Fluid level is checked with the engine running at
curb idle speed, the transmission in NEUTRAL and
the transmission fluid at normal operating tempera-
ture.The engine should be running at idle
speed for at least one minute, with the vehicle
on level ground.
The transmission fluid level can be checked two
ways.
PROCEDURE ONE
(1) Transmission fluid must be at normal operat-
ing temperature for accurate fluid level check. Drive
DRAUTOMATIC TRANSMISSION - 48RE 21 - 381

STANDARD PROCEDURE - FLUID AND FILTER
REPLACEMENT
For proper service intervals (Refer to LUBRICA-
TION & MAINTENANCE/MAINTENANCE SCHED-
ULES - DESCRIPTION). The service fluid fill after a
filter change is approximately 3.8 liters (4.0 quarts).
REMOVAL
(1) Hoist and support vehicle on safety stands.
(2) Place a large diameter shallow drain pan
beneath the transmission pan.
(3) Remove bolts holding front and sides of pan to
transmission (Fig. 91).
(4)
Loosen bolts holding rear of pan to transmission.
(5) Slowly separate front of pan and gasket away
from transmission allowing the fluid to drain into
drain pan.
(6) Hold up pan and remove remaining bolt hold-
ing pan to transmission.
(7) While holding pan level, lower pan and gasket
away from transmission.
(8) Pour remaining fluid in pan into drain pan.
(9) Remove screws holding filter to valve body
(Fig. 92).
(10) Separate filter from valve body and pour fluid
in filter into drain pan.
(11) Dispose of used trans fluid and filter properly.
INSTALLATION
(1) Position a new transmission oil filter onto the
valve body.
(2) Install the screws to hold the filter to the valve
body. Tighten the screws to 4 N´m (35 in.lbs.).
(3) Clean the gasket surfaces of the transmission
oil pan and transmission pan rail.NOTE: The transmission pan oil gasket is reusable.
Inspect the sealing surfaces of the gasket. If the
sealing ribs on both surfaces appear to be in good
condition, clean the gasket of any foreign material
and reinstall.
(4) Position the oil pan gasket onto the oil pan.
(5) Position the oil pan and gasket onto the trans-
mission and install several bolts to hold the pan and
gasket to the transmission.
(6) Install the remainder of the oil pan bolts.
Tighten the bolts to 13.6 N´m (125 in.lbs.).
(7) Lower vehicle and fill transmission. (Refer to
21 - TRANSMISSION/AUTOMATIC/FLUID - STAN-
DARD PROCEDURE)
STANDARD PROCEDURE - TRANSMISSION
FILL
To avoid overfilling transmission after a fluid
change or overhaul, perform the following procedure:
(1) Remove dipstick and insert clean funnel in
transmission fill tube.
(2) Add following initial quantity of MopartAT F
+4, Automatic Transmission Fluid, to transmission:
(a) If only fluid and filter were changed, add3
pints (1-1/2 quarts)of ATF +4 to transmission.
(b) If transmission was completely overhauled,
or torque converter was replaced or drained, add
12 pints (6 quarts)of ATF +4 to transmission.
(3) Apply parking brakes.
(4)
Start and run engine at normal curb idle speed.
(5)Apply service brakes, shift transmission through
all gear ranges then back to NEUTRAL, set parking
brake, and leave engine running at curb idle speed.
(6) Remove funnel, insert dipstick and check fluid
level. If level is low,add fluid to bring level to
MIN mark on dipstick.Check to see if the oil level
Fig. 91 Transmission Pan
1 - TRANSMISSION
2 - GASKET
3-PAN
Fig. 92 Transmission Filter
1 - TRANSMISSION
2 - FILTER
DRAUTOMATIC TRANSMISSION - 48RE 21 - 383
FLUID AND FILTER (Continued)

is equal on both sides of the dipstick. If one side is
noticably higher than the other, the dipstick has
picked up some oil from the dipstick tube. Allow the
oil to drain down the dipstick tube and re-check.
(7) Drive vehicle until transmission fluid is at nor-
mal operating temperature.
(8) With the engine running at curb idle speed, the
gear selector in NEUTRAL, and the parking brake
applied, check the transmission fluid level.
CAUTION: Do not overfill transmission, fluid foam-
ing and shifting problems can result.
(9)
Add fluid to bring level up to MAX arrow mark.
When fluid level is correct, shut engine off, release
park brake, remove funnel, and install dipstick in fill
tube.
FRONT CLUTCH
DESCRIPTION
The front clutch assembly (Fig. 93) is composed of
the front clutch retainer, pressure plate, clutch
plates, driving discs, piston, piston return spring,
return spring retainer, and snap-rings. The front
clutch is the forward-most component in the trans-
mission geartrain and is directly behind the oil pump
and is considered a driving component.
OPERATION
To apply the clutch, pressure is applied between the
clutch 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
the hub of the reaction shaft support. With pressure
applied between the clutch retainer and piston, the pis-
ton moves away from the clutch retainer and com-
presses 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 snap-ring is used to cushion the application
of the clutch pack.
When pressure is released from the piston, the spring
returns the piston to its fully released position and dis-
engages the clutch. The release spring also helps to
cushion the application of the clutch assembly. 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 clutch retainer. The
check-valve is needed to eliminate the possibility of
plate drag caused by centrifugal force acting on the
residual fluid trapped in the clutch piston retainer.
DISASSEMBLY
(1) Remove the waved snap-ring, reaction plate,
clutch plates, and clutch discs.
Fig. 93 48RE Front Clutch Components
1 - INNER PISTON SEAL 7 - CLUTCH DISCS
2 - CLUTCH PISTON 8 - RETAINER SNAP-RING
3 - CLUTCH PISTON SPRING RETAINER 9 - CLUTCH PISTON SPRINGS
4 - CLUTCH PLATES 10 - OUTER PISTON SEAL
5 - CLUTCH PACK SNAP-RING (WAVED) 11 - FRONT CLUTCH RETAINER
6 - REACTION PLATE
21 - 384 AUTOMATIC TRANSMISSION - 48REDR
FLUID AND FILTER (Continued)

OIL PUMP
DESCRIPTION
The oil pump (Fig. 111) is located in the pump
housing inside the bell housing of the transmission
case. The oil pump consists of an inner and outer
gear, a housing, and a reaction shaft support.
OPERATION
As the torque converter rotates, the converter hub
rotates the inner and outer gears. As the gears
rotate, the clearance between the gear teeth
increases in the crescent area, and creates a suction
at the inlet side of the pump. This suction draws
fluid through the pump inlet from the oil pan. As the
clearance between the gear teeth in the crescent area
decreases, it forces pressurized fluid into the pump
outlet and to the valve body.
Fig. 111 Oil Pump Assembly
1 - OIL SEAL 7 - BOLTS (6)
2 - VENT BAFFLE 8 - #1 THRUST WASHER (SELECTIVE)
3 - OIL PUMP BODY 9 - INNER GEAR
4 - GASKET 10 - OUTER GEAR
5 - REACTION SHAFT SUPPORT 11 - ªOº RING
6 - SEAL RINGS 12 - TORQUE CONVERTER SEAL RING
21 - 392 AUTOMATIC TRANSMISSION - 48REDR

CAUTION: The reaction shaft support seal rings will
break if overspread, or twisted. If new rings are
being installed, spread them only enough for instal-
lation. Also be very sure the ring ends are securely
hooked together after installation. Otherwise, the
rings will either prevent pump installation, or break
during installation.
(4) Align and install reaction shaft support on
pump body.
(5) Install bolts attaching reaction shaft support to
pump. Tighten bolts to 20 N´m (175 in. lbs.) torque.
Fig. 114 Oil Pump Assembly
1 - OIL SEAL 7 - BOLTS (6)
2 - VENT BAFFLE 8 - #1 THRUST WASHER (SELECTIVE)
3 - OIL PUMP BODY 9 - INNER GEAR
4 - GASKET 10 - OUTER GEAR
5 - REACTION SHAFT SUPPORT 11 - ªOº RING
6 - SEAL RINGS 12 - TORQUE CONVERTER SEAL RING
Fig. 115 Checking Pump Gear Tip Clearance
1 - FEELER GAUGE
2 - INNER GEAR
3 - OUTER GEAR
21 - 394 AUTOMATIC TRANSMISSION - 48REDR
OIL PUMP (Continued)

INSTALLATION
(1) Place replacement bearing in position in hous-
ing.
(2) Using a suitable driver, drive bearing into
housing until the snap-ring groove is visible.
(3) Install snap-ring to hold bearing into housing
(Fig. 118).
(4) Install overdrive geartrain into housing.
(5) Install overdrive unit in vehicle.
OVERDRIVE CLUTCH
DESCRIPTION
The overdrive clutch (Fig. 119) 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
provided 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 over-
drive clutch discs are attached to the overdrive clutch
hub while the overdrive clutch plates, reaction plate,
and pressure plate are lugged to the overdrive hous-
ing. This allows the intermediate shaft to transfer
the engine torque to the planetary gear and overrun-
ning 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
application of the clutch pack for the 5 disc version of
the overdrive clutch. The 6 disc overdrive clutch does
not use a waved snap-ring.
Fig. 119 Overdrive Clutch
1 - REACTION PLATE 2 - PRESSURE PLATE
21 - 396 AUTOMATIC TRANSMISSION - 48REDR
OUTPUT SHAFT REAR BEARING (Continued)

GEAR CASE
(1) Position park pawl and spring in case and
install park pawl shaft. Verify that end of spring
with 90É bend is hooked to pawl and straight end of
spring is seated against case.
(2) Install pawl shaft retaining bolt. Tighten bolt
to 27 N´m (20 ft. lbs.) torque.
(3) Install park lock reaction plug. Note that plug
has locating pin at rear (Fig. 169). Be sure pin is
seated in hole in case before installing snap-ring.
(4) Install reaction plug snap-ring (Fig. 170). Com-
press snap-ring only enough for installation; do not
distort it.(5) Verify that tab ends of rear bearing locating
ring extend into access hole in gear case (Fig. 171).
(6) Support geartrain on Tool 6227-1 (Fig. 172). Be
sure tool is securely seated in clutch hub.
(7) Install overdrive gear case on geartrain (Fig.
172).
Fig. 169 Reaction Plug Locating Pin And Snap-Ring
1 - REACTION PLUG SNAP-RING (DO NOT OVERCOMPRESS
TO INSTALL)
2 - LOCATING PIN
3 - PARK LOCK REACTION PLUG
Fig. 170 Reaction Plug And Snap-Ring Installation
1 - REACTION PLUG SNAP-RING
2 - SNAP-RING PLIERS
Fig. 171 Correct Rear Bearing Locating Ring
Position
1 - CASE ACCESS HOLE
2 - TAB ENDS OF LOCATING RING
Fig. 172 Overdrive Gear Case Installation
1 - GEARTRAIN ASSEMBLY
2 - GEAR CASE
DRAUTOMATIC TRANSMISSION - 48RE 21 - 411
OVERDRIVE UNIT (Continued)

(13) Install new gasket at rear of transmission
case. Use petroleum jelly to hold gasket in place. Be
sure to align governor feed holes in gasket with feed
passages in case (Fig. 192). Also install gasket before
overdrive piston retainer. Center hole in gasket is
smaller than retainer and cannot be installed over
retainer.
(14) Position overdrive piston retainer on trans-
mission case and align bolt holes in retainer, gasket
and case (Fig. 193). Then install and tighten retainer
bolts to 17 N´m (13 ft. lbs.) torque.
(15) Install new seals on overdrive piston.
(16) Stand transmission case upright on bellhous-
ing.
(17) Position Guide Ring 8114-1 on outer edge of
overdrive piston retainer.
(18) Position Seal Guide 8114-3 on inner edge of
overdrive piston retainer.
(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
Fig. 192 Installing/Aligning Case Gasket
1 - CASE GASKET
2 - BE SURE GOVERNOR TUBE FEED HOLES IN CASE AND
GASKET ARE ALIGNED
Fig. 193 Aligning Overdrive Piston Retainer
1 - PISTON RETAINER
2 - GASKET
3 - RETAINER BOLTS
21 - 418 AUTOMATIC TRANSMISSION - 48REDR
OVERRUNNING CLUTCH CAM/OVERDRIVE PISTON RETAINER (Continued)

(17) Check planetary geartrain end play with
feeler gauge (Fig. 218). 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. 219) 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. 218 Checking Planetary Geartrain End Play
1 - OUTPUT SHAFT
2 - REAR ANNULUS GEAR
3 - FEELER GAUGE
Fig. 219 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 - 426 AUTOMATIC TRANSMISSION - 48REDR
PLANETARY GEARTRAIN/OUTPUT SHAFT (Continued)