1998 DODGE RAM 1500 Transmission lines

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

(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)

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 damaged.
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.
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 annulus gear on output shaft, if
removed. Then install annulus gear retaining snap-
ring (Fig. 147).
(3) Align and install clutch drum on annulus gear
(Fig. 148). Be sure drum is engaged in annulus gear
lugs.
(4) Install clutch drum outer retaining ring (Fig.
148).
Fig. 147 Annulus Gear Installation
1 - SNAP-RING
2 - OUTPUT SHAFT FRONT BEARING
3 - ANNULUS GEAR
Fig. 148 Clutch Drum And Outer Retaining Ring
Installation
1 - ANNULUS GEAR
2 - OUTER SNAP-RING
3 - CLUTCH DRUM
21 - 226 AUTOMATIC TRANSMISSION - 48REDR
OVERDRIVE UNIT (Continued)

(5) Slide clutch drum forward and install inner
retaining ring (Fig. 149).
(6) Install rear bearing and snap-ring on output
shaft (Fig. 150). Be sure locating ring groove in bear-
ing is toward rear.
(7) Install overrunning clutch on hub (Fig. 151).
Note that clutch only fits one way. Shoulder on clutch
should seat in small recess at edge of hub.
(8) Install thrust bearing on overrunning clutch
hub. Use generous amount of petroleum jelly to hold
bearing in place for installation. Bearing fits one way
only. Be sure bearing is seated squarely against hub.
Reinstall bearing if it does not seat squarely.
(9) Install overrunning clutch in output shaft (Fig.
152). Insert snap-ring pliers in hub splines. Expand
pliers to grip hub. Then install assembly with coun-
terclockwise, twisting motion.
Fig. 152 Overrunning Clutch Installation
1 - CLUTCH DRUM
2 - OVERRUNNING CLUTCH ASSEMBLY
3 - EXPANDING-TYPE SNAP-RING PLIERS
4 - CLUTCH DRUM
5 - ANNULUS GEAR
6 - OVERRUNNING CLUTCH ASSEMBLY SEATED IN OUTPUT
SHAFT
Fig. 149 Clutch Drum Inner Retaining Ring
Installation
1 - ANNULUS GEAR
2 - INNER SNAP-RING
3 - CLUTCH DRUM
Fig. 150 Rear Bearing And Snap-Ring Installation
1 - REAR BEARING
2 - SNAP-RING
Fig. 151 Assembling Overrunning Clutch And Hub
1 - CLUTCH HUB
2 - OVERRUNNING CLUTCH
DRAUTOMATIC TRANSMISSION - 48RE 21 - 227
OVERDRIVE UNIT (Continued)

(10) Install planetary gear in annulus gear (Fig.
153). Be sure planetary pinions are fully seated in
annulus gear before proceeding.
(11) Coat planetary thrust bearing and bearing
contact surface of spring plate with generous amount
of petroleum jelly. This will help hold bearing in
place during installation.
(12) Install planetary thrust bearing on sun gear
(Fig. 154). Slide bearing onto gear and seat it against
spring plate as shown. Bearing fits one way only. If it
does not seat squarely against spring plate, remove
and reposition bearing.
(13) Install assembled sun gear, spring plate and
thrust bearing (Fig. 155). Be sure sun gear and
thrust bearing are fully seated before proceeding.(14) Mount assembled output shaft, annulus gear,
and clutch drum in shop press. Direct clutch spring,
hub and clutch pack are easier to install with assem-
bly mounted in press.
(15) Align splines in hubs of planetary gear and
overrunning clutch with Alignment tool 6227-2 (Fig.
156). Insert tool through sun gear and into splines of
both hubs. Be sure alignment tool is fully seated
before proceeding.
Fig. 156 Alignment Tool Installation
1 - SPECIAL TOOL 6227-2
2 - PRESS PLATES
3 - ASSEMBLED DRUM AND ANNULUS GEAR
4 - SUN GEAR
Fig. 153 Planetary Gear Installation
1 - PLANETARY GEAR
2 - ANNULUS GEAR
Fig. 154 Planetary Thrust Bearing Installation
1 - SPRING PLATE
2 - PLANETARY THRUST BEARING
3 - SUN GEAR
Fig. 155 Sun Gear Installation
1 - SUN GEAR AND SPRING PLATE ASSEMBLY
21 - 228 AUTOMATIC TRANSMISSION - 48REDR
OVERDRIVE UNIT (Continued)

(16) Install direct clutch spring (Fig. 157). Be sure
spring is properly seated on spring plate.
NOTE: The direct clutch in a 48RE transmission
uses 23 single-sided clutch discs.
(17) Assemble and install direct clutch pack on
hub as follows:
(a) Install direct clutch reaction plate on clutch
hub first. Note that one side of reaction plate is
counterbored. Be sure this side faces rearward.
Splines at rear of hub are raised slightly. Counter-
bore in plate fits over raised splines. Plate should
be flush with this end of hub (Fig. 158).(b) Install first clutch disc with internal splines
friction side up, followed by a disc with external
lugs friction side up. Continue alternating internal
and external discs until all discs have been
installed.
Fig. 158 Correct Position Of Direct Clutch Reaction
Plate
1-REACTION PLATE COUNTERBORE
2 - DIRECT CLUTCH REACTION PLATE (FLUSH WITH END OF HUB)
3 - CLUTCH HUB
Fig. 157 Direct Clutch Spring Installation
1 - SPECIAL TOOL 6227-2
2 - DIRECT CLUTCH SPRING
3 - CLUTCH HUB
4 - PRESS PLATES
DRAUTOMATIC TRANSMISSION - 48RE 21 - 229
OVERDRIVE UNIT (Continued)

(c) Install pressure plate. This is last clutch pack
item to be installed. Be sure plate is installed with
shoulder side facing upward (Fig. 159).
(18) Install clutch hub and clutch pack on direct
clutch spring (Fig. 160). Be sure hub is started on
sun gear splines before proceeding.WARNING: THE NEXT STEP IN GEARTRAIN
ASSEMBLY INVOLVES COMPRESSING THE DIRECT
CLUTCH HUB AND SPRING. IT IS EXTREMELY
IMPORTANT THAT PROPER EQUIPMENT BE USED
TO COMPRESS THE SPRING AS SPRING FORCE IS
APPROXIMATELY 830 POUNDS. USE COMPRES-
SOR TOOL C-6227-1 AND A HYDRAULIC-TYPE
SHOP PRESS WITH A MINIMUM RAM TRAVEL OF 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.
(19) Position Compressor Tool 6227-1 on clutch
hub.
(20) Compress clutch hub and spring just enough
to place tension on hub and hold it in place.
(21) Slowly compress clutch hub and spring. Com-
press spring and hub only enough to expose ring
grooves for clutch pack snap-ring and clutch hub
retaining ring.
(22) Realign clutch pack on hub and seat clutch
discs and plates in clutch drum.
(23) Install direct clutch pack snap-ring (Fig. 161).
Be very sure snap-ring is fully seated in clutch drum
ring groove.
Fig. 161 Direct Clutch Pack Snap-Ring Installation
1 - SPECIAL TOOL 6227-1
2 - DIRECT CLUTCH PACK SNAP-RING
Fig. 159 Correct Position Of Direct Clutch
1 - DIRECT CLUTCH PRESSURE PLATE
2 - CLUTCH PACK
3 - BE SURE SHOULDER SIDE OF PLATE FACES UPWARD
Fig. 160 Direct Clutch Pack And Clutch Hub
Installation
1 - CLUTCH HUB
2 - DIRECT CLUTCH PACK
3 - CLUTCH DRUM
21 - 230 AUTOMATIC TRANSMISSION - 48REDR
OVERDRIVE UNIT (Continued)

OD THRUST PLATE SELECTION
(1) Place overdrive unit in vertical position. Mount
it on blocks, or in workbench with appropriate size
mounting hole cut into it. Be sure unit is facing
upward for access to direct clutch hub. Also be sure
output shaft is not loaded and internal components
are moved rearward for accurate measurement.
(2) Determine correct thickness overdrive piston
thrust plate as follows:
(a) Position Gauge Tool 6311 across face of over-
drive case. Then position Dial Caliper C-4962 over
gauge tool (Fig. 174).
(b) Measure distance to clutch hub thrust bear-
ing seat at four points 90É apart. Then average
measurements by adding them and dividing by 4.
(c) Select and install required thrust plate from
information in thrust plate chart (Fig. 175).
(3) Leave Alignment Tool 6227-2 in place. Tool will
keep planetary and clutch hub splines in alignment
until overdrive unit is ready for installation on trans-
mission.
(4) Transmission speed sensor can be installed at
this time if desired. However, it is recommended that
sensor not be installed until after overdrive unit is
secured to transmission.
OVERDRIVE PISTON
(1) Install new seals on overdrive piston.
(2) Stand transmission case upright on bellhous-
ing.
(3) Position Guide Ring 8114-1 on outer edge of
overdrive piston retainer.
(4) Position Seal Guide 8114-3 on inner edge of
overdrive piston retainer.
(5) Install overdrive piston in overdrive piston
retainer by:
(a) Aligning locating lugs on overdrive piston to
the two mating holes in retainer.
(b) Lubricate overdrive piston seals with Mopart
ATF+4.
(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.
(6) Install intermediate shaft spacer on intermedi-
ate shaft.
(7) Install overdrive piston thrust plate on over-
drive piston.
(8) Install overdrive piston thrust bearing on over-
drive piston.
(9) Install transmission speed sensor and o-ring
seal in overdrive case.
Fig. 174 Overdrive Piston Thrust Plate Measurement
1 - SPECIAL TOOL 6311
2 - DIRECT CLUTCH HUB THRUST BEARING SEAT
3 - SPECIAL TOOL C-4962
Fig. 175 Overdrive Piston Thrust Plate Selection
21 - 234 AUTOMATIC TRANSMISSION - 48REDR
OVERDRIVE UNIT (Continued)