Clutch DODGE RAM 1500 1998 2.G Workshop Manual

Page 1908 of 2627

FRONT CLUTCH
DESCRIPTION
The front clutch assembly (Fig. 91) 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
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 actionapplies 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 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
clutch retainer. The check-valve is needed to elimi-
nate the possibility of plate drag caused by centrifu-
gal 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. 91 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
DRAUTOMATIC TRANSMISSION - 48RE 21 - 205

Page 1909 of 2627

(2) Compress clutch piston retainer and piston
springs with Compressor Tool C-3863-A (Fig. 92).
(3) Remove retainer snap-ring and remove com-
pressor tool.
(4) Remove clutch piston springs (Fig. 93). Note
position and number of piston springs for assembly
reference.
(5) Remove clutch piston from retainer with a
twisting motion.
(6) Remove and discard clutch piston inner and
outer seals.
INSPECTION
Inspect the front clutch components. Replace the
clutch discs if warped, worn, scored, burned or
charred, the lugs are damaged, or if the facing is
flaking off. Replace the steel plates and reaction
plate if heavily scored, warped, or broken. Be sure
the driving lugs on the discs and plate are also in
good condition. The lugs must not be bent, cracked or
damaged in any way.
Replace the piston springs and spring retainer if
either are distorted, warped or broken.
Check the lug grooves in the clutch piston retainer.
The steel plates should slide freely in the slots. Replace
the piston retainer if the grooves are worn or damaged.
Also check action of the check ball in the piston
retainer. The ball must move freely and not stick.
Replace the retainer bushing if worn, scored, or
there is any doubt about bushing condition.
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
Fig. 92 Removing Front Clutch Spring Retainer
Snap-Ring
1 - SPECIAL TOOL C-3863-A
2 - SNAP-RING
21 - 206 AUTOMATIC TRANSMISSION - 48REDR
FRONT CLUTCH (Continued)

Page 1910 of 2627

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 the clutch piston check ball. The ball should
be securely in place. Replace the piston if the ball is
missing, or seized in place.
ASSEMBLY
NOTE: The 48RE transmission uses five plates and
discs for the front clutch.
(1) Soak clutch discs in transmission fluid.
(2) Install new inner piston seal onto the outer
diameter of the clutch retainer inner hub.
(3)
Install new outer seal onto the clutch piston. Be
sure seal lips of both seals face the interior of the
retainer.
(4) Lubricate new inner and outer piston seals
with petroleum jelly.
(5) Install clutch piston in retainer. Use twisting
motion to seat piston in bottom of retainer. A thin
strip of plastic (about 0.015 - 0.020 in. thick), can be
used to guide seals into place if necessary.
CAUTION: Never push the clutch piston straight in.
This will fold the seals over causing leakage and
clutch slip. In addition, never use any type of metaltool to help ease the piston seals into place. Metal
tools will cut, shave, or score the seals.
(6) Install and position nine clutch piston springs
(Fig. 94).
(7) Install spring retainer on top of piston springs.
(8) Compress spring retainer and piston springs
with Tool C-3863-A.
(9) Install spring retainer snap-ring and remove
compressor tool.
(10) Install clutch plates and discs (Fig. 95). Five
clutch discs, five steel plates and one reaction plate
are required.
Fig. 94 Front Clutch Spring Position
1 - 9 SPRING CLUTCH
Fig. 95 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
DRAUTOMATIC TRANSMISSION - 48RE 21 - 207
FRONT CLUTCH (Continued)

Page 1911 of 2627

(11) Install reaction plate followed by waved snap-
ring.
(12) Check clutch pack clearance with feeler gauge
(Fig. 96). Clearance between waved spring and pres-
sure plate should 2.5-4.09 mm (0.098-0.161 in.). If
clearance is incorrect, clutch plates, clutch discs,
snap-ring, or pressure plate may have to be changed.
FRONT SERVO
DESCRIPTION
The kickdown servo (Fig. 97) consists of a two-land
piston with an inner piston, a piston rod and guide,
and a return spring. The dual-land piston uses seal
rings on its outer diameters and an O-ring for the
inner piston.
OPERATION
The application of the piston is accomplished by
applying pressure between the two lands of the pis-
ton. The pressure acts against the larger lower land
to push the piston downward, allowing the piston rod
to extend though its guide against the apply lever.
Release of the servo at the 2-3 upshift is accom-
plished by a combination of spring and line pressure,
acting on the bottom of the larger land of the piston.
The small piston is used to cushion the application of
the band by bleeding oil through a small orifice in
the larger piston. The release timing of the kickdown
servo is very important to obtain a smooth but firm
shift. The release has to be very quick, just as the
front clutch application is taking place. Otherwise,
engine runaway or a shift hesitation will occur. To
accomplish this, the band retains its holding capacity
until the front clutch is applied, giving a small
amount of overlap between them.
Fig. 96 Typical Method Of Measuring Front Clutch
Pack Clearance
1 - FEELER GAUGE
2 - WAVED SNAP-RING
3 - FEELER GAUGE
Fig. 97 Front Servo
1 - VENT
2 - INNER PISTON
3 - PISTON
4 - SPRING
5 - RELEASE PRESSURE
6 - APPLY PRESSURE
7 - PISTON ROD
21 - 208 AUTOMATIC TRANSMISSION - 48REDR
FRONT CLUTCH (Continued)

Page 1920 of 2627

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. 116).
(4) Install overdrive geartrain into housing.
(5) Install overdrive unit in vehicle.
OVERDRIVE CLUTCH
DESCRIPTION
The overdrive clutch (Fig. 117) 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. 117 Overdrive Clutch
1 - REACTION PLATE 2 - PRESSURE PLATE
DRAUTOMATIC TRANSMISSION - 48RE 21 - 217
OUTPUT SHAFT REAR BEARING (Continued)

Page 1921 of 2627

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. 118).
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. 119).
(2) Remove overdrive piston thrust bearing (Fig.
120).
Fig. 118 Overdrive Unit Bolts
1 - OVERDRIVE UNIT
2 - ATTACHING BOLTS (7)
Fig. 119 Transmission Speed Sensor
1 - SOCKET AND WRENCH
2 - SPEED SENSOR
3 - O-RING
21 - 218 AUTOMATIC TRANSMISSION - 48REDR

Page 1923 of 2627

OVERDRIVE CLUTCH PACK
(1) Remove overdrive clutch pack wire retaining
ring (Fig. 124).
(2) Remove overdrive clutch pack (Fig. 125).
(3) Note position of clutch pack components for
assembly reference (Fig. 126).
OVERDRIVE GEARTRAIN
(1) Remove overdrive clutch wave spring (Fig.
127), 5 disc clutch only.
(2) Remove overdrive clutch reaction snap-ring
(Fig. 128). Note that snap-ring is located in same
groove as wave spring.
Fig. 124 Removing Overdrive Clutch Pack Retaining
Ring
1 - OVERDRIVE CLUTCH PACK RETAINING RING
Fig. 125 Overdrive Clutch Pack Removal
1 - OVERDRIVE CLUTCH PACK
Fig. 126 Overdrive Clutch Component Position -
Typical
1 - REACTION PLATE
2 - CLUTCH PLATES
3 - PRESSURE PLATE
4 - CLUTCH DISCS
Fig. 127 Overdrive Clutch Wave Spring Removal - 5
Disc Clutch Only
1 - WAVE SPRING
Fig. 128 Overdrive Clutch Reaction Snap-Ring
Removal
1 - REACTION RING
2 - CLUTCH HUB
21 - 220 AUTOMATIC TRANSMISSION - 48REDR
OVERDRIVE UNIT (Continued)

Page 1925 of 2627

DIRECT CLUTCH, HUB AND SPRING
WARNING: THE NEXT STEP IN DISASSEMBLY
INVOLVES COMPRESSING THE DIRECT CLUTCH
SPRING. IT IS EXTREMELY IMPORTANT THAT PROPER
EQUIPMENT BE USED TO COMPRESS THE SPRING AS
SPRING FORCE IS APPROXIMATELY 830 POUNDS. USE
SPRING COMPRESSOR TOOL 6227-1 AND A HYDRAU-
LIC SHOP PRESS WITH A MINIMUM RAM TRAVEL OF
5-6 INCHES. THE PRESS MUST ALSO HAVE A BED
THAT CAN BE ADJUSTED UP OR DOWN AS REQUIRED.
RELEASE CLUTCH SPRING TENSION SLOWLY AND
COMPLETELY TO AVOID PERSONAL INJURY.
(1) Mount geartrain assembly in shop press (Fig. 134).
(2) Position Compressor Tool 6227-1 on clutch hub
(Fig. 134). Support output shaft flange with steel
press plates as shown and center assembly under
press ram.
(3) Apply press pressure slowly. Compress hub and
spring far enough to expose clutch hub retaining ring
and relieve spring pressure on clutch pack snap-ring
(Fig. 134).(4) Remove direct clutch pack snap-ring (Fig. 135).
(5)
Remove direct clutch hub retaining ring (Fig.
136).
Fig. 134 Geartrain Mounted In Shop Press
1 - PRESS RAM
2 - SPECIAL TOOL C-3995-A (OR SIMILAR TOOL)
3 - CLUTCH HUB
4 - PLATES
5 - PRESS BED
6 - SPECIAL TOOL 6227-1
Fig. 135 Direct Clutch Pack Snap-Ring Removal
1 - CLUTCH HUB
2 - SPECIAL TOOL 6227-1
3 - DIRECT CLUTCH PACK SNAP-RING
4 - PRESS PLATES
5 - CLUTCH DRUM
Fig. 136 Direct Clutch Hub Retaining Ring Removal
1 - SPECIAL TOOL 6227-1
2 - CLUTCH HUB RETAINING RING
3 - PRESS BED
4 - PRESS PLATES
21 - 222 AUTOMATIC TRANSMISSION - 48REDR
OVERDRIVE UNIT (Continued)

Page 1926 of 2627

(6) Release press load slowly and completely (Fig.
137).
(7) Remove Special Tool 6227-1. Then remove
clutch pack from hub (Fig. 137). Note the orientation
of the clutch discs. The clutch pack consists of 23 sin-
gle-sided discs and they must be installed in the
same orientation as they were removed.
GEARTRAIN
(1) Remove direct clutch hub and spring (Fig. 138).
(2) Remove sun gear and spring plate. Then
remove planetary thrust bearing and planetary gear
(Fig. 139).
Fig. 137 Direct Clutch Pack Removal
1 - SPECIAL TOOL 6227-1
2 - DIRECT CLUTCH HUB
3 - DIRECT CLUTCH PACK
Fig. 138 Direct Clutch Hub And Spring Removal
1 - DIRECT CLUTCH SPRING
2 - DIRECT CLUTCH HUB
Fig. 139 Removing Sun Gear, Thrust Bearing And
Planetary Gear
1 - PLANETARY GEAR
2 - PLANETARY THRUST BEARING
3 - CLUTCH SPRING PLATE
4 - SPRING PLATE SNAP-RING
5 - SUN GEAR
DRAUTOMATIC TRANSMISSION - 48RE 21 - 223
OVERDRIVE UNIT (Continued)

Page 1927 of 2627

(3) Remove overrunning clutch assembly with
expanding type snap-ring pliers (Fig. 140). Insert pli-
ers into clutch hub. Expand pliers to grip hub splines
and remove clutch with counterclockwise, twisting
motion.
(4) Remove thrust bearing from overrunning
clutch hub.
(5) Remove overrunning clutch from hub.
(6) Mark position of annulus gear and direct clutch
drum for assembly alignment reference (Fig. 141).
Use small center punch or scriber to make alignment
marks.(7) Remove direct clutch drum rear retaining ring
(Fig. 142).
(8) Remove direct clutch drum outer retaining ring
(Fig. 143).
Fig. 142 Clutch Drum Inner Retaining Ring Removal
1 - INNER RETAINING RING
2 - DIRECT CLUTCH DRUM
3 - ANNULUS GEAR
Fig. 143 Clutch Drum Outer Retaining Ring Removal
1 - OUTER RETAINING RING
Fig. 140 Overrunning Clutch Assembly Removal/
Installation
1 - OVERRUNNING CLUTCH
2 - NEEDLE BEARING
Fig. 141 Marking Direct Clutch Drum And Annulus
Gear For Assembly Alignment
1 - DIRECT CLUTCH DRUM
2 - HAMMER
3 - PUNCH
21 - 224 AUTOMATIC TRANSMISSION - 48REDR
OVERDRIVE UNIT (Continued)

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