1998 DODGE RAM 1500 Transmission shaft

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.
Fig. 112 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. 113 Checking Pump Gear Tip Clearance
1 - FEELER GAUGE
2 - INNER GEAR
3 - OUTER GEAR
DRAUTOMATIC TRANSMISSION - 48RE 21 - 215
OIL PUMP (Continued)

(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.
(6) Install new pump seal with Installer Tool
C-3860-A (Fig. 114). Use hammer or mallet to tap
seal into place.
(7) Install new o-ring on pump body. Lubricate oil
seal and o-ring with petroleum jelly.
(8) Cover pump assembly to prevent dust entry
and set aside for assembly installation.
OUTPUT SHAFT FRONT
BEARING
REMOVAL
(1) Remove overdrive unit from the vehicle.
(2) Remove overdrive geartrain from housing.
(3) Remove snap-ring holding output shaft front
bearing to overdrive geartrain. (Fig. 115).
(4) Pull bearing from output shaft.
INSTALLATION
(1) Place replacement bearing in position on
geartrain with locating retainer groove toward the
rear.
(2) Push bearing onto shaft until the snap-ring
groove is visible.
(3) Install snap-ring to hold bearing onto output
shaft.
(4) Install overdrive geartrain into housing.
(5) Install overdrive unit in vehicle.
OUTPUT SHAFT REAR
BEARING
REMOVAL
(1) Remove overdrive unit from the vehicle. (Refer
to 21 - TRANSMISSION/AUTOMATIC/OVERDRIVE
- REMOVAL)
(2) Remove overdrive geartrain from housing.
(3) Remove snap-ring holding output shaft rear
bearing into overdrive housing (Fig. 116).
(4) Using a suitable driver inserted through the
rear end of housing, drive bearing from housing.
Fig. 114 Oil Pump Seal
1 - SPECIAL TOOL C-3860-A
2 - PUMP BODY
3 - PUMP SEAL
Fig. 115 Output Shaft Front Bearing
1 - OUTPUT SHAFT FRONT BEARING
2 - SNAP-RING
3 - OUTPUT SHAFT
4 - GROOVE TO REAR
5 - OVERDRIVE GEARTRAIN
Fig. 116 Output Shaft Rear Bearing
1 - OUTPUT SHAFT REAR BEARING
2 - OVERDRIVE HOUSING
3 - SNAP-RING
21 - 216 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. 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)

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

OVERDRIVE PISTON
(1) Remove overdrive piston thrust plate (Fig.
121). Retain thrust plate. It is a select fit part and
may possibly be reused.(2) Remove intermediate shaft spacer (Fig. 122).
Retain spacer. It is a select fit part and may possibly
be reused.
(3) Remove overdrive piston from retainer (Fig.
123).
Fig. 120 Overdrive Piston Thrust Bearing Removal/
Installation
1 - THRUST BEARING
2 - OVERDRIVE PISTON
3 - THRUST PLATE
Fig. 121 Overdrive Piston Thrust Plate Removal/
Installation
1 - OVERDRIVE PISTON
2 - OVERDRIVE PISTON SPACER (SELECT FIT)
Fig. 122 Intermediate Shaft Spacer Location
1 - INTERMEDIATE SHAFT
2 - INTERMEDIATE SHAFT SPACER (SELECT FIT)
Fig. 123 Overdrive Piston Removal
1 - PISTON RETAINER
2 - OVERDRIVE PISTON
DRAUTOMATIC TRANSMISSION - 48RE 21 - 219
OVERDRIVE UNIT (Continued)

(3) Remove TorxŸ head screws that attach access
cover and gasket to overdrive case (Fig. 129).
(4) Remove access cover and gasket (Fig. 130).
(5) Expand output shaft bearing snap-ring with
expanding-type snap-ring pliers. Then push output
shaft forward to release shaft bearing from locating
ring (Fig. 131).(6) Lift gear case up and off geartrain assembly
(Fig. 132).
(7) Remove snap-ring that retains rear bearing on
output shaft.
(8) Remove rear bearing from output shaft (Fig.
133).
Fig. 129 Access Cover Screw Removal
1 - TORX SCREWDRIVER (T25)
2 - ACCESS COVER SCREWS
Fig. 130 Access Cover And Gasket Removal
1 - ACCESS COVER AND GASKET
Fig. 131 Releasing Bearing From Locating Ring
1 - EXPAND BEARING LOCATING RING WITH SNAP-RING
PLIERS
2 - ACCESS HOLE
Fig. 132 Removing Geartrain
1 - GEARTRAIN ASSEMBLY
2 - GEAR CASE
Fig. 133 Rear Bearing Removal
1 - OUTPUT SHAFT
2 - REAR BEARING
3 - SNAP-RING
DRAUTOMATIC TRANSMISSION - 48RE 21 - 221
OVERDRIVE UNIT (Continued)

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)

(9) Mark annulus gear and output shaft for assem-
bly alignment reference (Fig. 144). Use punch or
scriber to mark gear and shaft.
(10) Remove snap-ring that secures annulus gear
on output shaft (Fig. 145). Use two screwdrivers to
unseat and work snap-ring out of groove as shown.
(11) Remove annulus gear from output shaft (Fig.
146). Use rawhide or plastic mallet to tap gear off
shaft.
GEAR CASE AND PARK LOCK
(1) Remove locating ring from gear case.
(2) Remove park pawl shaft retaining bolt and
remove shaft, pawl and spring.
(3) Remove reaction plug snap-ring and remove
reaction plug.
(4) Remove output shaft seal.
CLEANING
Clean the geartrain and case components with sol-
vent. Dry all parts except the bearings with com-
pressed air. Allow bearings to air dry.
Do not use shop towels for wiping parts dry unless
the towels are made from a lint-free material. A suf-
ficient quantity of lint (from shop towels, cloths, rags,
etc.) could plug the transmission filter and fluid pas-
sages.
Discard the old case gasket and seals. Do not
attempt to salvage these parts. They are not reus-
able. Replace any of the overdrive unit snap-rings if
distorted or damaged.
Minor nicks or scratches on components can be
smoothed with crocus cloth. However, do not attempt
to reduce severe scoring on any components with
abrasive materials. Replace severely scored compo-
nents; do not try to salvage them.
INSPECTION
Check condition of the park lock components and
the overdrive case.
Check the bushings in the overdrive case. Replace
the bushings if severely scored or worn. Also replace
the case seal if loose, distorted, or damaged.
Examine the overdrive and direct clutch discs and
plates. Replace the discs if the facing is worn,
severely scored, or burned and flaking off. Replace
the clutch plates if worn, heavily scored, or cracked.
Fig. 144 Marking Annulus Gear And Output Shaft
For Assembly Alignment
1 - OUTPUT SHAFT
2 - HAMMER
3 - PUNCH
Fig. 145 Annulus Gear Snap-Ring Removal
1 - OUTPUT SHAFT
2 - ANNULUS GEAR
3 - SNAP-RING
Fig. 146 Annulus Gear Removal
1 - OUTPUT SHAFT
2 - ANNULUS GEAR
DRAUTOMATIC TRANSMISSION - 48RE 21 - 225
OVERDRIVE UNIT (Continued)