ADAPTER HOUSING SEAL
REMOVAL
(1) Raise and support vehicle.
(2) Mark the propeller shafts and yokes for instal-
lation reference and remove the shafts.
(3) Support transmission with a transmission jack.
(4) Remove engine rear support.
(5) Remove transfer case.
(6) Remove adapter housing seal with a pry tool or
slide hammer mounted screw (Fig. 130).
INSTALLATION
(1) Install adapter housing seal with Installer
C-3860-A and Handle C-4171.
(2) Install transfer case.
(3) Install propeller shafts with reference marks
aligned.
(4) Fill transfer case and transmission to proper
level.
(5) Remove support and lower vehicle.
EXTENSION HOUSING SEAL
REMOVAL
(1) Mark the propeller shaft and yoke for installa-
tion reference.
(2) Remove the propeller shaft.
(3) Remove extension housing seal (Fig. 131) using
Remover C-3985-B.
(4) On heavy duty 4X2 vehicles, remove extension
housing seal with a pry tool or a slide hammer
mounted screw.(5) On light duty transmissions, remove the exten-
sion housing bushing with Remover 6957.
(6) On heavy duty transmissions, remove the
extension housing bushing with Remover 8155.
INSTALLATION
(1) Install housing bushing with Handle C-4171
(Fig. 132) and Installer.
²Light Duty - Installer 6951
²Heavy Duty - Installer 8161
Fig. 130 Adapter Housing (4±Wheel Drive Models)
1 - ADAPTER HOUSING
2 - SEAL
Fig. 131 EXTENSION HOUSING AND SEAL (4X2)
1 - EXTENSION HOUSING
2 - SEAL
Fig. 132 Extension Housing Bushing
1 - HANDLE
2 - INSTALLER
3 - EXTENSION HOUSING
DRMANUAL TRANSMISSION - NV4500 21 - 85
(2) Install housing seal with Handle C-4171 (Fig.
133) and Installer.
²Light Duty - Installer C-3972-A
²Heavy Duty - Installer 8154
(3) Install propeller shaft with reference marks
aligned.
(4) Check and fill transmission.
SHIFT MECHANISM
REMOVAL
(1) Remove transmission from vehicle.
(2) Remove shift mechanism cover bolts.
(3) Pry up shift mechanism cover at slots provided
in cover (Fig. 134).
(4) Raise cover enough to disengage it from align-
ment dowels in gear case (Fig. 135).
(5) Raise front of shift mechanism cover and lift
cover up and off gear case (Fig. 135).
FIFTH-REVERSE SHIFT FORK PADS
Three shift pads on the forks are held in place by
tension and a small locating tang (Fig. 136).
To remove the pads, grasp a pad with hand and tilt
it out and off the fork. If pad is difficult to remove by
hand, insert a screwdriver blade between the pad
and fork and pry the pad off.
EXPANSION PLUG
The expansion plugs at the rear of the shift rail
bores (Fig. 137) can be replaced if loose/leaking.
(1) Drill 6 mm (1/4 in.) diameter hole in center of
the plug to be removed.
(2) Pry plug out of cover with tapered punch.
Fig. 133 Pinion Seal
1 - HANDLE
2 - INSTALLER
Fig. 134 LOOSEN SHIFT MECHANISM
1 - SHIFT MECHANISM COVER SLOT
2-PRYTOOL
Fig. 135 SHIFT MECHANISM COVER
1 - SHIFT MECHANISM COVER
2 - ALIGNMENT DOWELS
Fig. 136 SHIFT FORK PAD LOCATIONS
1 - SHIFT FORK PADS
2 - FIFTH-REVERSE FORK
21 - 86 MANUAL TRANSMISSION - NV4500DR
EXTENSION HOUSING SEAL (Continued)
IDENTIFICATION
The transmission has two identification tags
attached to the driver side upper clutch housing (Fig.
2). One tag provides the transmission part number.
The second tag provides sequencing and build date
information. The information on the tags are essen-
tial to correct parts ordering.
OPERATION
The driver selects a particular gear by moving the
shift lever to the desired gear position. As the shift
lever moves the selected shift rail, the shift fork
attached to that rail begins to move. The fork is posi-
tioned in a groove in the outer circumference of the
synchronizer sleeve. As the shift fork moves the syn-
chronizer sleeve, the synchronizer begins to speed-up
or slow down the selected gear (depending on
whether we are up-shifting or down-shifting). The
synchronizer does this by having the synchronizer
hub splined to the mainshaft or the countershaft in
some cases, and moving the blocker ring into contact
with the gear's friction cone. As the blocker ring and
friction cone come together, the gear speed is brought
up or down to the speed of the synchronizer. As the
two speeds match, the splines on the inside of the
synchronizer sleeve become aligned with the teeth on
the blocker ring and friction cone and eventually will
slide over the teeth, locking the gear to the main-
shaft or countershaft through the synchronizer.
DIAGNOSIS AND TESTING
LOW LUBRICANT LEVEL
A low transmission lubricant level is generally the
result of a leak, inadequate lubricant fill or an incor-
rect lubricant level check. A correct lubricant level
check can only be made when the vehicle is level.
Also allow the lubricant to settle for a minute or sobefore checking. These recommendations will ensure
an accurate check and avoid an underfill or overfill
condition. Always check the lubricant level after any
addition of fluid to avoid an incorrect lubricant level
condition.
Leaks can occur at the mating surfaces of the gear
case, adaptor or extension housing, or from the front/
rear seals. A suspected leak could also be the result
of an overfill condition. Leaks at the rear of the
extension or adapter housing will be from the hous-
ing oil seals. Leaks at component mating surfaces
will probably be the result of inadequate sealer, gaps
in the sealer, incorrect bolt tightening or use of a
non-recommended sealer. A leak at the front of the
transmission will be from either the front bearing
retainer or retainer seal. Lubricant may be seen drip-
ping from the clutch housing after extended opera-
tion. If the leak is severe, it may also contaminate
the clutch disc causing the disc to slip, grab and or
chatter.
HARD SHIFTING
Hard shifting is usually caused by a low lubricant
level, improper or contaminated lubricants. The con-
sequence of using non-recommended lubricants is
noise, excessive wear, internal bind and hard shift-
ing. Substantial lubricant leaks can result in gear,
shift rail, synchro, and bearing damage. If a leak
goes undetected for an extended period, the first indi-
cations of component damage are usually hard shift-
ing and noise.
Component damage, incorrect clutch adjustment or
damaged clutch pressure plate or disc are additional
probable causes of increased shift effort. Incorrect
adjustment or a worn/damaged pressure plate or disc
can cause incorrect release. If clutch problem is
advanced, gear clash during shifts can result. Worn
or damaged synchro rings can cause gear clash when
shifting into any forward gear. In some new or
rebuilt transmissions, new synchro rings may tend to
stick slightly causing hard or noisy shifts. In most
cases this condition will decline as the rings wear-in.
TRANSMISSION NOISE
Most manual transmissions make some noise dur-
ing normal operation. Rotating gears generate a mild
whine that is audible, but generally only at extreme
speeds. Severe highly audible transmission noise is
generally the initial indicator of a lubricant problem.
Insufficient, improper or contaminated lubricant
will promote rapid wear of gears, synchros, shift
rails, forks and bearings. The overheating caused by
a lubricant problem, can also lead to gear breakage.
REMOVAL
(1) Shift transmission into Neutral.
Fig. 2 IDENTIFICATION TAG LOCATION
1 - IDENTIFICATION TAGS
21 - 90 MANUAL TRANSMISSION - NV5600DR
MANUAL TRANSMISSION - NV5600 (Continued)
(2) Remove screws attaching shift boot to floorpan.
Then slide boot upward on the shift lever.
(3) Remove the bolts holding the shift tower to the
isolator plate and transmission gear case.
(4) Remove the shift tower and isolator plate from
the transmission gear case.
(5) Raise and support vehicle.
(6) Remove skid plate, if equipped.
(7) Mark propeller shaft/shafts and axle yokes for
installation reference.
(8) Remove propeller shaft.
(9) Disconnect and remove exhaust system as nec-
essary.
(10) Disconnect wires at backup light switch.
(11) Support engine with adjustable safety stand
and wood block.
(12) If transmission is to be disassembled for
repair, remove drain bolt at bottom of PTO cover and
drain lubricant from transmission (Fig. 3).
(13) Remove clutch slave cylinder splash shield, if
equipped.
(14) Remove clutch slave cylinder bolts and move
cylinder aside for clearance.
(15)
Remove wire harness from clips on transmission.
TWO WHEEL DRIVE
(1) Remove bolts/nuts mounting transmission to
the rear mount.
(2) Support and secure transmission with safety
chains to a transmission jack.
(3) Remove rear crossmember bolts and pry out
crossmember.
(4) Remove transmission clutch housing bolts at
the engine block.
(5) Slide transmission and jack rearward until
input shaft clears clutch disc and pressure plate.
(6) Lower transmission jack and remove transmis-
sion from under vehicle.
FOUR WHEEL DRIVE
(1) Disconnect transfer case shift linkage at trans-
fer case range lever.
(2) Support and secure transfer case with safety
chains to a transmission jack.
(3) Remove transfer case mounting nuts.
(4) Move transfer case rearward until input gear
clears transmission mainshaft.
(5) Lower transfer case assembly and move it from
under vehicle.
(6) Support and secure transmission with safety
chains to a transmission jack.
(7) Remove bolts/nuts attaching transmission
mount to rear crossmember.
(8) Remove rear crossmember bolts and pry out
crossmember.
(9) Remove transmission clutch housing bolts at
the engine block.
(10) Move transmission rearward until input shaft
clears clutch disc.
(11) Lower transmission and remove it from under
vehicle.
DISASSEMBLY
NOTE: Use Fixture 8241 for moving and handling
the transmission. The fixture supports the transmis-
sion at the center of gravity in order to ease mount-
ing the transmission into the build fixture.
(1)
Mount the transmission into Fixture 8230 (Fig. 4).
Fig. 3 NV5600 DRAIN BOLT
1 - PTO COVER
2 - DRAIN BOLT
Fig. 4 TRANSMISSION FIXTURE
1 - FIXTURE
2 - TRANSMISSION
DRMANUAL TRANSMISSION - NV5600 21 - 91
MANUAL TRANSMISSION - NV5600 (Continued)
(1) Apply a light coat of Mopar high temperature
bearing grease or equivalent to contact surfaces of
following components:
²input shaft splines.
²release bearing slide surface of front retainer.
²release bearing bore.
²release fork.
²release fork ball stud.
²propeller shaft slip yoke.
(2) Apply sealer to threads of bottom PTO cover
bolt and install bolt in case.
(3) Mount transmission on jack and position trans-
mission under vehicle.
(4) Raise transmission until input shaft is centered
in clutch disc hub.
(5) Move transmission forward and start input
shaft in clutch disc and pilot bushing/bearing.
(6)
Work transmission forward until seated against
engine block. Do not allow transmission to remain
unsupported after input shaft has entered clutch disc.
(7) Install and tighten transmission-to-engine
block bolts.
(8) Install clutch slave cylinder.
(9) Connect backup light switch wires.
(10) Position transmission harness wires in clips
on transmission.
(11) Install transmission mount on transmission or
rear crossmember.
(12) Install rear crossmember.
(13) Remove transmission jack and engine support
fixture.
(14)
Fill transmission with required lubricant (Fig.
96). Check lubricant level in transfer case if equipped.
TWO WHEEL DRIVE
(1) Install propeller shaft with referece marks
aligned.
(2) Install exhaust system components.(3) Remove support and lower vehicle.
(4) Shift transmission into third gear.
(5) Clean the mating surfaces of shift tower and
isolator plate with suitable wax and grease remover.
(6) Apply Mopar Gasket Maker or equivalent to
sealing surface of the transmission case. Do not over
apply sealant.
(7) Install isolator plate onto the transmission case
metal side down.
(8) Install shift tower onto the isolator plate. No
sealant is necessary between the shift tower and top
of isolator plate.
(9) Verify shift tower, isolator plate and the shift
socket are properly aligned.
(10) Install bolts to hold the shift tower to the iso-
lator plate and the transmission case. Tighten bolts
to 10.2±11.25 N´m (7.5±8.3 ft. lbs.).
(11) Install shift boot and bezel.
FOUR WHEEL DRIVE
(1) Install and secure transfer case on the trans-
mission jack.
(2) Raise and align transfer case input gear with
transmission mainshaft.
(3) Move transfer case forward and seat it on
adapter.
(4)
Install and tighten transfer case mounting nuts to
41-47 N´m (30-35 ft. lbs.) if case has 3/8 studs. If case
has 5/16 studs tighten to 30-41 N´m (22-30 ft. lbs.).
(5) Connect transfer case shift lever to range lever
on transfer case.
(6) Install propeller shafts with reference marks
aligned.
(7) Install transfer case skid plate, if equipped,
and crossmember. Tighten attaching bolts/nuts to 41
N´m (30 ft. lbs.).
(8) Install exhaust system components.
(9) Remove support and lower vehicle.
(10) Shift transmission into third gear.
(11) Clean the mating surfaces of shift tower, iso-
lator plate and transmission case with suitable wax
and grease remover.
(12) Apply Mopar Gasket Maker or equivalent to
the sealing surface of the transmission case. Do not
over apply sealant.
(13) Install isolator plate onto the transmission
case, metal side down.
(14) Install shift tower onto the isolator plate. No
sealant is necessary between the shift tower and top
of isolator plate.
(15) Verify that the shift tower, isolator plate and
the shift tower bushings are properly aligned.
(16) Install the bolts to hold the shift tower to the
isolator plate and the transmission case. Tighten the
shift tower bolts to 10.2-11.25 N´m (7.5-8.3 ft. lbs.).
(17) Install shift lever boot and bezel.
Fig. 96 FILL PLUG
1 - FILL PLUG
21 - 122 MANUAL TRANSMISSION - NV5600DR
MANUAL TRANSMISSION - NV5600 (Continued)
OUTPUT SHAFT FRONT BEARING
REMOVAL............................216
INSTALLATION........................216
OUTPUT SHAFT REAR BEARING
REMOVAL............................216
INSTALLATION........................217
OVERDRIVE CLUTCH
DESCRIPTION........................217
OPERATION..........................217
OVERDRIVE UNIT
REMOVAL............................218
DISASSEMBLY........................218
CLEANING...........................225
INSPECTION.........................225
ASSEMBLY...........................226
INSTALLATION........................235
OVERRUNNING CLUTCH CAM/OVERDRIVE
PISTON RETAINER
DESCRIPTION........................236
OPERATION..........................236
DISASSEMBLY........................236
CLEANING...........................236
INSPECTION.........................237
ASSEMBLY...........................237
PISTONS
DESCRIPTION........................239
OPERATION..........................239
PLANETARY GEARTRAIN/OUTPUT SHAFT
DESCRIPTION........................241
OPERATION..........................241
DISASSEMBLY........................242
INSPECTION.........................243
ASSEMBLY...........................244
REAR CLUTCH
DESCRIPTION........................247
OPERATION..........................248
DISASSEMBLY........................248
CLEANING...........................248
INSPECTION.........................248
ASSEMBLY...........................249
REAR SERVO
DESCRIPTION........................251
OPERATION..........................251
DISASSEMBLY........................251
CLEANING...........................251
ASSEMBLY...........................251
SHIFT MECHANISM
DESCRIPTION........................252OPERATION..........................252
SOLENOID
DESCRIPTION........................252
OPERATION..........................252
SPEED SENSOR
DESCRIPTION........................253
OPERATION..........................253
THROTTLE VALVE CABLE
DESCRIPTION........................253
ADJUSTMENTS - THROTTLE VALVE CABLE . 254
TORQUE CONVERTER
DESCRIPTION........................255
OPERATION..........................259
REMOVAL............................260
INSTALLATION........................260
TORQUE CONVERTER DRAINBACK VALVE
DESCRIPTION........................261
OPERATION..........................261
STANDARD PROCEDURE - TORQUE
CONVERTER DRAINBACK VALVE........261
TOW/HAUL OVERDRIVE SWITCH
DESCRIPTION........................261
OPERATION..........................262
DIAGNOSIS AND TESTING - OVERDRIVE
ELECTRICAL CONTROLS..............262
REMOVAL............................262
INSTALLATION........................262
TRANSMISSION RANGE SENSOR
DESCRIPTION........................263
OPERATION..........................263
DIAGNOSIS AND TESTING - TRANSMISSION
RANGE SENSOR (TRS)................264
REMOVAL............................265
INSTALLATION........................266
TRANSMISSION TEMPERATURE SENSOR
DESCRIPTION........................267
OPERATION..........................267
VALVE BODY
DESCRIPTION........................267
OPERATION..........................272
REMOVAL............................286
DISASSEMBLY........................287
CLEANING...........................298
INSPECTION.........................298
ASSEMBLY...........................299
INSTALLATION........................309
ADJUSTMENTS - VALVE BODY...........310
DRAUTOMATIC TRANSMISSION - 48RE 21 - 131
AUTOMATIC TRANSMISSION -
48RE
DESCRIPTION
The 48RE (Fig. 1) is a four speed fully automatic
transmissions with an electronic governor. The 48RE
is equipped with a lock-up clutch in the torque con-
verter. First through third gear ranges are provided
by the clutches, bands, overrunning clutch, and plan-
etary gear sets in the transmission. Fourth gear
range is provided by the overdrive unit that contains
an overdrive clutch, direct clutch, planetary gear set,
and overrunning clutch.
The transmission contains a front, rear, and direct
clutch which function as the input driving compo-
nents. It also contains the kickdown (front) and thelow/reverse (rear) bands which, along with the over-
running clutch and overdrive clutch, serve as the
holding components. The driving and holding compo-
nents combine to select the necessary planetary gear
components, in the front, rear, or overdrive planetary
gear set, transfer the engine power from the input
shaft through to the output shaft.
The valve body is mounted to the lower side of the
transmission and contains the valves to control pres-
sure regulation, fluid flow control, and clutch/band
application. The oil pump is mounted at the front of
the transmission and is driven by the torque con-
verter hub. The pump supplies the oil pressure nec-
essary for clutch/band actuation and transmission
lubrication.
21 - 132 AUTOMATIC TRANSMISSION - 48REDR
IDENTIFICATION
Transmission identification numbers are stamped
on the left side of the case just above the oil pan gas-
ket surface (Fig. 2). Refer to this information when
ordering replacement parts.
GEAR RATIOS
The 48RE gear ratios are:
1st.................................2.45:1
2nd................................1.45:1
3rd................................1.00:1
4th.................................0.69:1
Rev.................................2.20:1
OPERATION
The application of each driving or holding compo-
nent is controlled by the valve body based upon the
manual lever position, throttle pressure, and gover-
nor pressure. The governor pressure is a variable
pressure input to the valve body and is one of the
signals that a shift is necessary. First through fourth
gear are obtained by selectively applying and releas-
ing the different clutches and bands. Engine power is
thereby routed to the various planetary gear assem-
blies which combine with the overrunning clutch
assemblies to generate the different gear ratios. The
torque converter clutch is hydraulically applied and
is released when fluid is vented from the hydraulic
circuit by the torque converter control (TCC) solenoid
on the valve body. The torque converter clutch is con-
trolled by the Powertrain Control Module (PCM). The
torque converter clutch engages in fourth gear, and
in third gear under various conditions, such as when
the O/D switch is OFF, when the vehicle is cruising
on a level surface after the vehicle has warmed up.
The torque converter clutch can also be engaged in
the MANUAL SECOND gear position if high trans-
mission temperatures are sensed by the PCM. The
torque converter clutch will disengage momentarily
when an increase in engine load is sensed by the
PCM, such as when the vehicle begins to go uphill or
the throttle pressure is increased. The torque con-
verter clutch feature increases fuel economy and
reduces the transmission fluid temperature.
Since the overdrive clutch is applied in fourth gear
only and the direct clutch is applied in all ranges
except fourth gear, the transmission operation for
park, neutral, and first through third gear will be
described first. Once these powerflows are described,
the third to fourth shift sequence will be described.
1 - TORQUE CONVERTER 10 - OVERDRIVE CLUTCH
2 - INPUT SHAFT 11 - DIRECT CLUTCH
3 - OIL PUMP 12 - PLANETARY GEAR
4 - FRONT BAND 13 - INTERMEDIATE SHAFT
5 - FRONT CLUTCH 14 - OVERDRIVE OVERRUNNING CLUTCH
6 - REAR CLUTCH 15 - DIRECT CLUTCH SPRING
7 - PLANETARIES 16 - OVERDRIVE PISTON RETAINER
8 - REAR BAND 17 - OIL PAN
9 - OVERRUNNING CLUTCH 18 - VALVE BODY
Fig. 2 Transmission Part Number And Serial
Number Location
1 - PART NUMBER
2 - BUILD DATE
3 - SERIAL NUMBER
21 - 134 AUTOMATIC TRANSMISSION - 48REDR
AUTOMATIC TRANSMISSION - 48RE (Continued)