1998 DODGE RAM 1500 Over drive

(5) Slowly separate front of pan and reusable gas-
ket away from transmission allowing the fluid to
drain into drain pan.
(6) Hold up pan and remove remaining bolt hold-
ing pan to transmission.
(7) While holding pan level, lower pan and gasket
away from transmission.
(8) Pour remaining fluid in pan into drain pan.
(9) Remove screws holding filter to valve body
(Fig. 90).
(10) Separate filter from valve body and pour fluid
in filter into drain pan.
(11) Dispose of used trans fluid and filter properly.
INSTALLATION
(1) Position a new transmission oil filter onto the
valve body.
(2) Install the screws to hold the filter to the valve
body. Tighten the screws to 4 N´m (35 in.lbs.).
(3) Clean the gasket surfaces of the transmission
oil pan and transmission pan rail.
NOTE: The transmission pan oil gasket is reusable.
Inspect the sealing surfaces of the gasket. If the
sealing ribs on both surfaces appear to be in good
condition, clean the gasket of any foreign material
and reinstall.
(4) Position the oil pan gasket onto the oil pan.
(5) Position the oil pan and gasket onto the trans-
mission and install several bolts to hold the pan and
gasket to the transmission.(6) Install the remainder of the oil pan bolts.
Tighten the bolts to 13.6 N´m (125 in.lbs.).
(7) Lower vehicle and fill transmission. (Refer to
21 - TRANSMISSION/AUTOMATIC/FLUID - STAN-
DARD PROCEDURE)
STANDARD PROCEDURE - TRANSMISSION
FILL
To avoid overfilling transmission after a fluid
change or overhaul, perform the following procedure:
(1) Remove dipstick and insert clean funnel in
transmission fill tube.
(2) Add following initial quantity of MopartAT F
+4 to transmission:
(a) If only fluid and filter were changed, add3
pints (1-1/2 quarts)of ATF +4 to transmission.
(b) If transmission was completely overhauled,
torque converter was replaced or drained, and
cooler was flushed, add12 pints (6 quarts)of ATF
+4 to transmission.
(3) Apply parking brakes.
(4) Start and run engine at normal curb idle
speed.
(5) Apply service brakes, shift transmission
through all gear ranges then back to NEUTRAL, set
parking brake, and leave engine running at curb idle
speed.
(6) Remove funnel, insert dipstick and check fluid
level. If level is low,add fluid to bring level to
MIN mark on dipstick.Check to see if the oil level
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.
Fig. 90 Transmission Filter
1 - TRANSMISSION
2 - FILTER
21 - 204 AUTOMATIC TRANSMISSION - 48REDR
FLUID AND FILTER (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)

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)

(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)