clutch DODGE RAM 2003 Service Repair Manual

HYDRAULIC FLOW IN DRIVE THIRD GEAR (CONVERTER CLUTCH APPLIED)
21 - 362 AUTOMATIC TRANSMISSION - 48REDR
AUTOMATIC TRANSMISSION - 48RE (Continued)

HYDRAULIC FLOW IN DRIVE FOURTH GEAR (CONVERTER CLUTCH NOT APPLIED)
DRAUTOMATIC TRANSMISSION - 48RE 21 - 363
AUTOMATIC TRANSMISSION - 48RE (Continued)

HYDRAULIC FLOW IN DRIVE FOURTH GEAR (CONVERTER CLUTCH APPLIED)
21 - 364 AUTOMATIC TRANSMISSION - 48REDR
AUTOMATIC TRANSMISSION - 48RE (Continued)

SPECIFICATIONS
TRANSMISSION
GENERAL
Component Metric Inch
Planetary end play 0.150-1.22
mm0.006-0.048
in.
Input shaft end play 0.86-2.13
mm0.034-0.084
in.
Clutch pack clearance/
Front.2.5-4.09
mm0.098-0.161
in.
Clutch pack clearance/
Rear.0.635-0.914
mm0.025-0.036
in.
Front clutch 5 discs
Rear clutch 4 discs
Overdrive clutch 5(STD) or 6 (HO) discs
Direct clutch 23 single sided discs
Band adjustment from
72 in. lbs.
Front band Back off 1 3/4 turns
Rear band Back off 3 turns
Recommended fluid MoparTATF +4, Automatic
Transmission FluidGEAR RATIOS
1ST GEAR 2.45:1
2ND GEAR 1.45:1
3RD GEAR 1.00:1
4TH GEAR 0.69:1
REVERSE 2.21:1
THRUST WASHER/SPACER/SNAP-RING DIMENSIONS
Component Metric Inch
Front clutch thrust washer (reaction shaft support
hub)1.55 mm 0.061 in.
2.15 mm 0.084 in.
2.59 mm 0.102 in.
Rear clutch thrust washer (clutch retainer) 1.55 mm 0.061 in.
Intermediate shaft thrust plate (shaft hub pilot) 1.5-1.6 mm 0.060-0.063 in.
Output shaft thrust washer (rear clutch hub) 1.3-1.4 mm 0.052-0.054 in.
1.75-1.8 mm 0.068-0.070 in.
2.1-2.2 mm 0.083-0.085 in.
Rear clutch pack snap-ring 1.5-1.6 mm 0.060-0.062 in.
1.9-1.95 mm 0.074-0.076 in.
Planetary geartrain snap-ring (at front of output
shaft)1.4-1.5 mm 0.055-0.059 in.
1.6-1.7 mm 0.062-0.066 in.
Overdrive piston thrust plate Thrust plate and spacer are select
fit. Refer to size charts and
selection procedures in Overdrive
Unit D&A procedures Intermediate shaft spacer
21 - 368 AUTOMATIC TRANSMISSION - 48REDR
AUTOMATIC TRANSMISSION - 48RE (Continued)

TORQUE SPECIFICATIONS
DESCRIPTION N´m Ft. Lbs. In. Lbs.
Fitting, cooler line at trans 18 13 -
Bolt, torque convertor 31 - 270
Bolt, clevis bracket to
crossmember47 35 -
Bolt, clevis bracket to rear
support68 50 -
Bolt, driveplate to
crankshaft75 55 -
Plug, front band reaction 17 13 -
Locknut, front band adj. 34 25 -
Bolt, fluid pan 17 13 -
Screws, fluid filter 4 - 35
Bolt, oil pump 20 15 -
Bolt, overrunning clutch
cam17 13 -
Bolt, O/D to trans. 34 25 -
Bolt, O/D piston retainer 17 13 -
Plug, pressure test port 14 10 -
Bolt, reaction shaft
support20 15 -
Locknut, rear band 41 30 -
Bolt, valve body to case 12 - 100
Sensor, trans speed 27 20 -
Screw, solenoid wiring
connector4-35
Screw, solenoid to transfer
plate4-35
Bracket, transmission
range sensor mounting34 - 300
Screw, transmission range
sensor to mounting
bracket3.4 - 30
DRAUTOMATIC TRANSMISSION - 48RE 21 - 369
AUTOMATIC TRANSMISSION - 48RE (Continued)

ACCUMULATOR
DESCRIPTION
The accumulator (Fig. 68) is a hydraulic device
that has the sole purpose of cushioning the applica-
tion of a band or clutch. The accumulator consists of
a dual-land piston and a spring located in a bore in
the transmission case. The 3-4 accumulator is located
in a housing attached to the side of the valve body
(Fig. 69).
Retainer, Detent Ball and Spring - 6583
Installer, Overdrive Piston Seal - 8114
Socket, TRS Mounting Bracket - 8581
Installer, Seal - 9037
Fig. 68 Accumulator
1 - ACCUMULATOR PISTON
2 - PISTON SPRING
Fig. 69 3-4 Accumulator and Housing
1 - ACCUMULATOR PISTON
2 - 3-4 ACCUMULATOR HOUSING
3 - TEFLON SEALS
4 - PISTON SPRING
5 - COVER PLATE AND SCREWS
21 - 372 AUTOMATIC TRANSMISSION - 48REDR
AUTOMATIC TRANSMISSION - 48RE (Continued)

OPERATION
Both the accumulator and the 3-4 accumulator
function the same. Line pressure is directed to the
small end of the piston when the transmission is
placed into a DRIVE position (Fig. 70), bottoming it
against the accumulator plate. When the 1-2 upshift
occurs (Fig. 71), line pressure is directed to the large
end of the piston and then to the kickdown servo. As
the line pressure reaches the accumulator, the com-
bination of spring pressure and line pressure forces
the piston away from the accumulator plate. This
causes a balanced pressure situation, which results
in a cushioned band application. After the kickdown
servo has become immovable, line pressure will fin-
ish pushing the accumulator up into its bore. When
the large end of the accumulator piston is seated in
its bore, the band or clutch is fully applied.
NOTE: The accumulator is shown in the inverted
position for illustrative purposes.
INSPECTION
Inspect the accumulator piston and seal rings.
Replace the seal rings if worn or cut. Replace the pis-
ton if chipped or cracked.
Check condition of the accumulator spring. Replace
the spring if the coils are cracked, distorted or col-
lapsed.
BANDS
DESCRIPTION
KICKDOWN (FRONT) BAND
The kickdown, or ªfrontº, band (Fig. 72) holds the
common sun gear of the planetary gear sets. The
front (kickdown) band is made of steel, and faced on
its inner circumference with a friction-type lining.
One end of the band is anchored to the transmission
case, and the other is acted on with a pushing force
by a servo piston. The front band is a single-wrap
design (the band does not completely encompass/
wrap the drum that it holds).
Fig. 70 Accumulator in DRIVE - FIRST Gear Position
1 - LINE PRESSURE
Fig. 71 Accumulator in SECOND Gear Position
1 - BOTTOM OF BORE
2 - LINE PRESSURE
3 - SHUTTLE VALVE
DRAUTOMATIC TRANSMISSION - 48RE 21 - 373
ACCUMULATOR (Continued)

LOW/REVERSE (REAR) BAND
The low/reverse band, or ªrearº, band (Fig. 73) is sim-
ilar in appearance and operation to the front band. The
rear band is slightly different in that it does not use a
link bar, but is acted directly on by the apply lever. This
is referred to as a double-wrap band design (the drum is
completely encompassed/wrapped by the band). The
double-wrap band provides a greater holding power in
comparison to the single-wrap design.
OPERATION
KICKDOWN (FRONT) BAND
The kickdown band holds the common sun gear of
the planetary gear sets by applying and holding thefront clutch retainer, which is splined to the sun gear
driving shell, and in turn splined directly to the sun
gear. The application of the band by the servo is typ-
ically done by an apply lever and link bar.
LOW/REVERSE (REAR) BAND
The rear band holds the rear planet carrier sta-
tionary by being mounted around and applied to the
low/reverse drum.
ADJUSTMENTS
ADJUSTMENT - BANDS
FRONT BAND
The front (kickdown) band adjusting screw is
located on the left side of the transmission case
above the manual valve and throttle valve levers.
(1) Raise vehicle.
(2) Loosen band adjusting screw locknut (Fig. 74).
Then back locknut off 3-5 turns. Be sure adjusting
screw turns freely in case. Apply lubricant to screw
threads if necessary.
(3) Tighten band adjusting screw to 8 N´m (72 in.
lbs.) torque with Inch Pound Torque Wrench
C-3380-A, a 3-in. extension and an appropriate
TorxŸ socket.
CAUTION: If Adapter C-3705 is needed to reach the
adjusting screw, tighten the screw to only 5 N´m
(47-50 in. lbs.) torque.
(4)
Back off front band adjusting screw 1-3/4 turns.
(5) Hold adjuster screw in position and tighten
locknut to 41 N´m (30 ft. lbs.) torque.
(6) Lower vehicle.
Fig. 72 Front Band
1 - FRONT BAND
2 - TRANSMISSION HOUSING
Fig. 73 Rear Band
1 - ADJUSTING SCREW
2 - LOCKNUT
3 - LEVER
4 - REAR BAND
5 - REACTION PIN
6 - O-RINGS
7 - PIVOT PIN
Fig. 74 Front Band Adjustment Screw Location
1 - LOCK-NUT
2 - FRONT BAND ADJUSTER
21 - 374 AUTOMATIC TRANSMISSION - 48REDR
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

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)