1998 DODGE RAM 1500 Drive shaft

(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)

(24) Install clutch hub retaining ring (Fig. 162). Be
very sure retaining ring is fully seated in sun gear
ring groove.
(25) Slowly release press ram, remove compressor
tools and remove geartrain assembly.
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. 163). Be sure pin is
seated in hole in case before installing snap-ring.
(4) Install reaction plug snap-ring (Fig. 164). 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. 165).
(6) Support geartrain on Tool 6227-1 (Fig. 166). Be
sure tool is securely seated in clutch hub.
Fig. 165 Correct Rear Bearing Locating Ring
Position
1 - CASE ACCESS HOLE
2 - TAB ENDS OF LOCATING RING
Fig. 162 Clutch Hub Retaining Ring Installation
1 - SPECIAL TOOL 6227-1
2 - CLUTCH HUB RETAINING RING
Fig. 163 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. 164 Reaction Plug And Snap-Ring Installation
1 - REACTION PLUG SNAP-RING
2 - SNAP-RING PLIERS
DRAUTOMATIC TRANSMISSION - 48RE 21 - 231
OVERDRIVE UNIT (Continued)

(5) Install first clutch disc followed by first clutch
plate. Then install remaining clutch discs and plates
in same order.
(6) Install clutch pack pressure plate.
(7) Install clutch pack wire-type retaining ring
(Fig. 171).
INTERMEDIATE SHAFT SPACER 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 intermediate shaft
spacer as follows:
(a) Insert Special Tool 6312 through sun gear,
planetary gear and into pilot bushing in output
shaft. Be sure tool bottoms against planetary
shoulder.
(b) Position Gauge Tool 6311 across face of over-
drive case (Fig. 172). Then position Dial Caliper
C-4962 over gauge tool.(c) Extend sliding scale of dial caliper downward
through gauge tool slot until scale contacts end of
Gauge Alignment Tool 6312. Lock scale in place.
Remove dial caliper tool and note distance mea-
sured (Fig. 172).
(d) Select proper thickness end play spacer from
spacer chart based on distance measured (Fig.
173).
(e) Remove Gauge Alignment Tool 6312.
Fig. 171 Overdrive Clutch Pack Retaining Ring
Installation
1 - OVERDRIVE CLUTCH PACK RETAINING RINGFig. 172 Shaft End Play Measurement
1 - SPECIAL TOOL 6312
2 - SPECIAL TOOL 6311
3 - SPECIAL TOOL C-4962
Fig. 173 Intermediate Shaft End Play Spacer
Selection
DRAUTOMATIC TRANSMISSION - 48RE 21 - 233
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)

INSTALLATION
(1) Be sure overdrive unit Alignment Tool 6227-2
is fully seated before moving unit. If tool is not
seated and gear splines rotate out of alignment, over-
drive unit will have to be disassembled in order to
realign splines.
(2) If overdrive piston retainer was not removed
during service and original case gasket is no longer
reusable, prepare new gasket by trimming it.
(3) Cut out old case gasket around piston retainer
with razor knife (Fig. 176).
(4) Use old gasket as template and trim new gas-
ket to fit.
(5) Position new gasket over piston retainer and
on transmission case. Use petroleum jelly to hold
gasket in place if necessary. Do not use any type of
sealer to secure gasket. Use petroleum jelly only.
(6) Install selective spacer on intermediate shaft, if
removed. Spacer goes in groove just rearward of
shaft rear splines (Fig. 177).
(7) Install thrust bearing in overdrive unit sliding
hub. Use petroleum jelly to hold bearing in position.
CAUTION: Be sure the shoulder on the inside diam-
eter of the bearing is facing forward.(8) Verify that splines in overdrive planetary gear
and overrunning clutch hub are aligned with Align-
ment Tool 6227-2. Overdrive unit cannot be installed
if splines are not aligned. If splines have rotated out
of alignment, unit will have to be disassembled to
realign splines.
(9) Carefully slide Alignment Tool 6227-2 out of
overdrive planetary gear and overrunning clutch
splines.
(10) Raise overdrive unit and carefully slide it
straight onto intermediate shaft. Insert park rod into
park lock reaction plug at same time. Avoid tilting
overdrive during installation as this could cause
planetary gear and overrunning clutch splines to
rotate out of alignment. If this occurs, it will be nec-
essary to remove and disassemble overdrive unit to
realign splines.
(11) Work overdrive unit forward on intermediate
shaft until seated against transmission case.
(12) Install bolts attaching overdrive unit to trans-
mission unit. Tighten bolts in diagonal pattern to 34
N´m (25 ft-lbs).
(13) Connect the transmission speed sensor and
overdrive wiring connectors.
(14) Install the transfer case, if equipped.
(15) Align and install rear propeller shaft, if nec-
essary. (Refer to 3 - DIFFERENTIAL & DRIVELINE/
PROPELLER SHAFT/PROPELLER SHAFT -
INSTALLATION)
Fig. 176 Trimming Overdrive Case Gasket
1 - GASKET
2 - SHARP KNIFE
Fig. 177 Intermediate Shaft Selective Spacer
Location
1 - SELECTIVE SPACER
2 - SPACER GROOVE
3 - INTERMEDIATE SHAFT
DRAUTOMATIC TRANSMISSION - 48RE 21 - 235
OVERDRIVE UNIT (Continued)

OVERRUNNING CLUTCH
CAM/OVERDRIVE PISTON
RETAINER
DESCRIPTION
The overrunning clutch (Fig. 178) consists of an
inner race, an outer race (or cam), rollers and
springs, and the spring retainer. The number of roll-
ers and springs depends on what transmission and
which overrunning clutch is being dealt with.
OPERATION
As the inner race is rotated in a clockwise direction
(as viewed from the front of the transmission), the
race causes the rollers to roll toward the springs,
causing them to compress against their retainer. The
compression of the springs increases the clearance
between the rollers and cam. This increased clear-
ance between the rollers and cam results in a free-
wheeling condition. When the inner race attempts to
rotate counterclockwise, the action causes the rollers
to roll in the same direction as the race, aided by the
pushing of the springs. As the rollers try to move in
the same direction as the inner race, they are
wedged between the inner and outer races due to the
design of the cam. In this condition, the clutch is
locked and acts as one unit.
DISASSEMBLY
(1) Remove the overdrive piston (Fig. 179).
(2) Remove the overdrive piston retainer bolts.
(3) Remove overdrive piston retainer.
(4) Remove case gasket.(5) Tap old cam out of case with pin punch. Insert
punch through bolt holes at rear of case (Fig. 180).
Alternate position of punch to avoid cocking cam dur-
ing removal.
(6) Clean clutch cam bore and case. Be sure to
remove all chips/shavings generated during cam
removal.
CLEANING
Clean the overrunning clutch assembly, clutch cam,
low-reverse drum, and overdrive piston retainer in
solvent. Dry them with compressed air after clean-
ing.
Fig. 178 Overrunning Clutch
1 - OUTER RACE (CAM)
2 - ROLLER
3 - SPRING
4 - SPRING RETAINER
5 - INNER RACE (HUB)
Fig. 179 Overdrive Piston Removal
1 - OVERDRIVE CLUTCH PISTON
2 - INTERMEDIATE SHAFT
3 - SELECTIVE SPACER
4 - PISTON RETAINER
Fig. 180 Overrunning Clutch Cam
1 - PIN PUNCH
2 - REAR SUPPORT BOLT HOLES
21 - 236 AUTOMATIC TRANSMISSION - 48REDR

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. 191) 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. 192) 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:²The sun gear which is at the center of the sys-
tem.
²The planet carrier with planet pinion gears
which are free to rotate on their own shafts and are
in mesh with the sun gear.
²The annulus gear, which rotates around and is
in mesh with the planet pinion gears.
NOTE: The number of pinion gears does not affect
the gear ratio, only the duty rating.
OPERATION
With any given planetary gearset, several condi-
tions must be met for power to be able to flow:
²One member must be held.
²Another member must be driven or used as an
input.
²The third member may be used as an output for
power flow.
²For direct drive to occur, two gear members in
the front planetary gearset must be driven.
NOTE: Gear ratios are dependent on the number of
teeth on the annulus and sun gears.
Fig. 191 Piston Travel
Fig. 192 Planetary Gearset
1 - ANNULUS GEAR
2 - SUN GEAR
3 - PLANET CARRIER
4 - PLANET PINIONS (4)
DRAUTOMATIC TRANSMISSION - 48RE 21 - 241
PISTONS (Continued)

(10) Install the spacer ring and wave spring into
the retainer. Be sure spring is completely seated in
retainer groove.
(11) Install pressure plate (Fig. 214). Ridged side
of plate faces downward (toward piston) and flat side
toward clutch pack.
(12) Install first clutch disc in retainer on top of
pressure plate. Then install a clutch plate followed
by a clutch disc until entire clutch pack is installed
(4 discs and 3 plates are required) (Fig. 214).
(13) Install the reaction plate.
(14) Install selective snap-ring. Be sure snap-ring
is fully seated in retainer groove.
(15) Using a suitable gauge bar and dial indicator,
measure clutch pack clearance (Fig. 216).
(a) Position gauge bar across the clutch drum
with the dial indicator pointer on the pressure
plate (Fig. 216).
(b) Using two small screw drivers, lift the pres-
sure plate and release it.
(c) Zero the dial indicator.
(d) Lift the pressure plate until it contacts the
snap-ring and record the dial indicator reading.
Clearance should be 0.635 - 0.914 mm (0.025 -
0.036 in.). If clearance is incorrect, steel plates, discs,
selective snap ring and pressure plates may have to
be changed.
The selective snap ring thicknesses are:²0.107 - 0.109 in.
²0.098 - 0.100 in.
²0.095 - 0.097 in.
²0.083 - 0.085 in.
²0.076 - 0.078 in.
²0.071 - 0.073 in.
²0.060 - 0.062 in.
(16) Coat rear clutch thrust washer with petro-
leum jelly and install washer over input shaft and
into clutch retainer (Fig. 217). Use enough petroleum
jelly to hold washer in place.
(17) Set rear clutch aside for installation during
final assembly.
Fig. 215 Pressing Input Shaft Into Rear Clutch
Retainer
1 - INPUT SHAFT
2 - REAR CLUTCH RETAINER
3 - PRESS RAM
Fig. 216 Checking Rear Clutch Pack Clearance
1 - DIAL INDICATOR
2 - PRESSURE PLATE
3 - SNAP-RING
4-STAND
5 - REAR CLUTCH
6 - GAUGE BAR
Fig. 217 Installing Rear Clutch Thrust Washer
1 - REAR CLUTCH RETAINER
2 - REAR CLUTCH THRUST WASHER
21 - 250 AUTOMATIC TRANSMISSION - 48REDR
REAR CLUTCH (Continued)