
TRANSMISSION AND TRANSFER CASE
TABLE OF CONTENTS
page page
MANUAL TRANSMISSION - NV3500..........1
MANUAL TRANSMISSION - NV4500..........42
MANUAL TRANSMISSION - NV5600..........87
AUTOMATIC TRANSMISSION - 46RE........129
AUTOMATIC TRANSMISSION - 48RE........310
AUTOMATIC TRANSMISSION - 45RFE/545RFE. . 488
TRANSFER CASE - NV241 GENII...........591
TRANSFER CASE - NV271................623
TRANSFER CASE - NV243................658
TRANSFER CASE - NV273................687
MANUAL TRANSMISSION - NV3500
TABLE OF CONTENTS
page page
MANUAL TRANSMISSION - NV3500
DESCRIPTION..........................1
OPERATION............................1
DIAGNOSIS AND TESTING................3
REMOVAL.............................3
DISASSEMBLY..........................4CLEANING............................15
INSPECTION..........................15
ASSEMBLY............................17
INSTALLATION.........................38
SPECIFICATIONS.......................39
SPECIAL TOOLS.......................40
MANUAL TRANSMISSION -
NV3500
DESCRIPTION
The transmission is a medium-duty 5-speed, con-
stant mesh fully synchronized manual transmission
with fifth gear overdrive range. The transmission is
available in two and four-wheel drive configurations.
The transmission gear case consists of two aluminum
housings (Fig. 1). The clutch housing is an integral
part of the transmission front housing.
A combination of roller and ball bearings are used
to support the transmission shafts in the two hous-
ings. The transmission gears all rotate on caged type
needle bearings. A roller bearing is used between the
input and output shaft.
The transmission has a single shaft shift mecha-
nism with three shift forks all mounted on the shaft.
The shaft is supported in the front and rear housings
by bushings and one linear ball bearing. Internal
shift components consist of the forks, shaft, shift
lever socket and detent components
OPERATION
The manual transmission receives power through the
clutch assembly from the engine. The clutch disc issplined to the transmission input shaft and is turned at
engine speed at all times that the clutch is engaged.
The input shaft is connected to the transmission coun-
tershaft through the mesh of fourth speed gear on the
input shaft and the fourth countershaft gear. At this
point, all the transmission gears are spinning.
The driver selects a particular gear by moving the
shift lever to the desired gear position. This move-
ment moves the internal transmission shift compo-
nents to begin the shift sequence. As the shift lever
moves the selected shift rail, the shift fork attached
to that rail begins to move. The fork is positioned in
a groove in the outer circumference of the synchro-
nizer sleeve. As the shift fork moves the synchronizer
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 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 the friction cone and eventually
will slide over the teeth, locking the gear to the
mainshaft, or countershaft, through the synchronizer.
DRTRANSMISSION AND TRANSFER CASE 21 - 1

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. Leaks can occur at the
mating surfaces of the gear case, adaptor or exten-
sion housing, or from the front/rear seals. A sus-
pected leak could also be the result of an overfill
condition.
Leaks at the rear of the extension or adapter hous-
ing will be from the housing oil seals. Leaks at com-
ponent 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 dripping from the clutch
housing after extended operation. If the leak is
severe, it may also contaminate the clutch disc caus-
ing the disc to slip, grab and or chatter.
A correct lubricant level check can only be made
when the vehicle is level. Also allow the lubricant to
settle for a minute or so before checking. These rec-
ommendations 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.
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.
Shift component damage or damaged clutch pres-
sure plate or disc are additional probable causes of
increased shift effort. 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 gener-
ally 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 and bearing
damage.
REMOVAL
(1) Disconnect battery negative cable.
(2) Shift transmission into Neutral.
(3) Remove shift boot bezel screws and slide boot
upward on shift lever extension.
(4) Remove shift lever extension from the shift
tower and lever assembly.
(5) Raise vehicle on hoist.
(6) Remove skid plate, if equipped.
(7) Drain lubricant if transmission will be disas-
sembled for service.
(8) Mark propeller shaft/shafts and companion
flange yoke/yokes for installation reference and
remove propeller shaft/shafts.
(9) Disconnect harness from clips on transmission
housing.
(10) Remove transfer case linkage if equipped.
(11) Remove transfer case mounting nuts and
remove transfer case if equipped.
(12) Remove slave cylinder mounting nut and
remove cylinder (Fig. 2).
Fig. 2 SLAVE CYLINDER
1 - MOUNTING NUTS
2 - SLAVE CYLINDER
DRMANUAL TRANSMISSION - NV3500 21 - 3
MANUAL TRANSMISSION - NV3500 (Continued)

(6) Install fifth gear synchro ring in synchro hub
and sleeve (Fig. 55).
(7) Install fifth gear bearing. Spread bearing only
enough to clear shoulder on output shaft (Fig. 56).
Verify bearing is properly seated.(8) Install fifth gear on shaft and onto bearing
(Fig. 57).
(9) Invert output shaft and set the shaft in Collar
6310-1 so fifth gear is seated on the tool (Fig. 58).
(10) Install first gear bearing on output shaft (Fig.
58). Verify bearing is seated on shaft shoulder and is
properly joined.
Fig. 55 FIFTH GEAR SYNCHRO RING
1 - FIFTH-SPEED SYNCHRO RING
2 - FIFTH-REVERSE SYNCHRO ASSEMBLY
Fig. 56 FIFTH GEAR BEARING
1 - SHAFT SHOULDER
2 - FIFTH GEAR BEARING
Fig. 57 FIFTH GEAR
1 - FIFTH GEAR
2 - BEARING
Fig. 58 FIRST GEAR
1 - FIRST GEAR BEARING
2 - SHAFT SHOULDER
3 - COLLAR
4 - PRESS BLOCKS
DRMANUAL TRANSMISSION - NV3500 21 - 19
MANUAL TRANSMISSION - NV3500 (Continued)

(24) Install third gear needle bearing on shaft (Fig.
70).
(25) Install third gear on shaft and bearing (Fig.
71).(26) Install third speed synchro ring on third gear
(Fig. 72).
(27) Start 3-4 synchro hub on output shaft splines
by hand (Fig. 73).
CAUTION: The 3-4 synchro hub and sleeve can be
installed backwards if care is not exercised. One
side of the sleeve has grooves in it, this side must
faces the front of the shaft.
Fig. 70 THIRD GEAR BEARING
1 - THIRD GEAR BEARING
Fig. 71 THIRD GEAR
1 - THIRD GEAR
2 - BEARING
Fig. 72 THIRD GEAR SYNCHRO RING
1 - THIRD SPEED SYNCHRO RING
2 - THIRD GEAR
Fig. 73 3-4 SYNCHRO HUB ON OUTPUT SHAFT
1 - GROOVED SIDE OF SLEEVE
2 - 3-4 SYNCHRO ASSEMBLY
DRMANUAL TRANSMISSION - NV3500 21 - 23
MANUAL TRANSMISSION - NV3500 (Continued)

(28) Press 3-4 synchro assembly onto output shaft
with shop press and suitable size pipe (Fig. 74).
NOTE: Tool presses on hub must be as close to
output shaft as possible but not contacting the
shaft splines.
(29) Installnew3-4 synchro hub snap ring (Fig.
75). Verify snap ring is seated in groove.(30) Install output shaft bearing.
(31) Install output shaft bearing snap ring with
heavy duty snap ring pliers (Fig. 76). Verify snap
ring is seated in shaft groove.
NOTE: Spread snap ring only enough to install it.
(32) Verify position of synchro sleeves before pro-
ceeding (Fig. 77). Grooved side of 3-4 sleeve must
face forward. First gear side of 1-2 sleeve must face
first gear. Tapered side of fifth-reverse sleeve must
face forward.
REVERSE IDLER ASSEMBLY
(1) Lubricate idler components with gear lube.
(2) Slide idler gear bearing on shaft (Fig. 78).
Bearing fits either way on shaft.
(3) Slide gear onto shaft. Side of gear with recess
goes to rear (Fig. 78).
(4) Place first lock ball in dimple at rear end of
idler shaft (Fig. 78). Petroleum jelly can be used to
hold ball in place if desired.
(5) Slide thrust rear thrust washer onto shaft and
over lock ball (Fig. 79).
(6) Install snap ring in groove at rear of shaft (Fig.
79).
Fig. 74 3-4 SYNCHRO ON OUTPUT SHAFT
1 - PRESS RAM
2 - PIPE TOOL
3 - 3-4 SYNCHRO
4 - THIRD SPEED SYNCHRO RING
Fig. 75 3-4 SYNCHRO HUB SNAP RING
1 - 3-4 SYNCHRO HUB SNAP RING
2 - HEAVY DUTY SNAP RING PLIERS
Fig. 76 OUTPUT SHAFT BEARING SNAP
1 - BEARING SNAP RING
2 - HEAVY DUTY SNAP RING PLIERS
21 - 24 MANUAL TRANSMISSION - NV3500DR
MANUAL TRANSMISSION - NV3500 (Continued)

MANUAL TRANSMISSION - NV4500
TABLE OF CONTENTS
page page
MANUAL TRANSMISSION - NV4500
DESCRIPTION.........................42
OPERATION...........................42
DIAGNOSIS AND TESTING................43
REMOVAL.............................43
DISASSEMBLY.........................44
CLEANING............................60
INSPECTION..........................60
ASSEMBLY............................61
INSTALLATION.........................77
SPECIFICATIONS.......................79
SPECIAL TOOLS.......................79ADAPTER HOUSING SEAL
REMOVAL.............................83
INSTALLATION.........................83
EXTENSION HOUSING SEAL
REMOVAL.............................83
INSTALLATION.........................83
SHIFT MECHANISM
REMOVAL.............................84
INSTALLATION.........................85
SHIFT COVER
REMOVAL.............................86
INSTALLATION.........................86
MANUAL TRANSMISSION -
NV4500
DESCRIPTION
The NV4500 is a five speed constant mesh manual
transmission. All gear ranges including reverse are
synchronized. Fifth gear is an overdrive range. The
transmission has a cast iron gear case and aluminum
shift cover.
Two versions are used, a standard duty for 5.7L
applications and a heavy duty for V10 and Cummins
diesel applications. Main difference is a larger diam-
eter input shaft, for the heavy duty model.
Tapered roller bearings support the drive gear,
mainshaft and countershaft in the gear case. Roller
bearings in the drive gear support the forward end of
the mainshaft. The mainshaft gears are all supported
on caged type roller bearings. Drive gear thrust reac-
tion is controlled by a needle type thrust bearing.
The bearing is located at the forward end of the
mainshaft.
The transmission is a top loader style. The shift
lever is located in a shifter tower which is bolted to
the shift cover and operates the shift forks and rails
directly. The shift forks and rails are all located
within the aluminum cover which is bolted to the top
of the gear case.
IDENTIFICATION
The transmission identification tag is attached to
the driver side PTO cover (Fig. 1).
The tag provides the transmission model number,
build date and part number. Be sure to reinstall the
I.D. tag if removed during service. The information
on the tag is essential to correct parts ordering.
OPERATION
The manual transmission receives power through
the clutch assembly from the engine. The clutch disc
is splined to the transmission input shaft and is
turned at engine speed at all times that the clutch is
engaged. The input shaft is connected to the trans-
mission countershaft through the mesh of fourth
speed gear on the input shaft and the fourth counter-
shaft gear. At this point all the transmission gears
are spinning.
Fig. 1 IDENTIFICATION TAG LOCATION
1 - PTO COVER
2 - I.D. TAG
21 - 42 MANUAL TRANSMISSION - NV4500DR

The driver selects a particular gear by moving the
shift lever to the desired gear position. This move-
ment moves the internal transmission shift compo-
nents to begin the shift sequence. As the shift lever
moves the selected shift rail, the shift fork attached
to that rail begins to move. The fork is positioned in
a groove in the outer circumference of the synchro-
nizer sleeve. As the shift fork moves the synchronizer
sleeve, the synchronizer begins to speed-up or slow
down the selected gear (depending on whether the
driver is up-shifting or down-shifting). The synchro-
nizer 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 fric-
tion 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 syn-
chronizer sleeve become aligned with the teeth on
the blocker ring and the friction cone and eventually
will slide over the teeth, locking the gear to the
mainshaft, 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 so
before 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 isnoise, 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.
(2) Remove shift boot screws from floorpan and
slide boot upward on the shift lever.
(3) Remove shift lever extension from shift tower
and lever assembly.
(4) Remove shift tower bolts (Fig. 2).
Fig. 2 SHIFT TOWER
1 - SHIFT TOWER
2 - SHIFTER
3 - BOLTS
DRMANUAL TRANSMISSION - NV4500 21 - 43
MANUAL TRANSMISSION - NV4500 (Continued)

(5) Remove shift tower and isolator plate from
transmission shift cover.
(6) Raise and support vehicle.
(7) Remove skid plate, if equipped.
(8) Mark propeller shaft and axle yokes for instal-
lation reference and remove shaft/shafts.
(9) Remove exhaust system Y-pipe.
(10) Disconnect speed sensor and backup light
switch connectors.
(11) Support engine with safety stand and a wood
block.
(12) If transmission is to be disassembled, remove
drain bolt at bottom of PTO cover and drain lubri-
cant (Fig. 3).
TWO WHEEL DRIVE
(1) Remove bolts attaching transmission to rear
crossmember mount.
(2) Support and secure transmission with safety
chains to a transmission jack.
(3) Remove rear crossmember bolts and pry out
crossmenber.
(4) Remove clutch slave cylinder bolts and move
cylinder aside for clearance.
NOTE: The hydraulic linkage has a quick connect at
the slave cylinder. This fitting should not be discon-
nected.
(5) Remove transmission harness wires from clips
on transmission shift cover.
(6) Remove transmission to clutch housing bolts.
(7) Slide transmission and jack rearward until
input shaft clears clutch housing.
(8) 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. Then remove transfer case shift
mechanism from transmission (Fig. 4).(2) Support and secure transfer case to transmis-
sion jack with safety chains.
(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 transmission harness from retaining
clips on transmission shift cover.
(8) Remove bolts/nuts attaching transmission
mount to rear crossmember.
(9) Remove rear crossmember bolts and pry out
crossmenber.
(10) Remove clutch slave cylinder splash shield, if
equipped.
(11) Remove clutch slave cylinder bolts and move
cylinder aside for clearance.
NOTE: The hydraulic linkage has a quick connect at
the slave cylinder. This fitting should not be discon-
nected.
(12) Remove transmission to clutch housing bolts.
(13) Slide transmission and jack rearward until
input shaft clears clutch housing.
(14) Lower transmission jack and remove trans-
mission from under vehicle.
DISASSEMBLY
SHIFT MECHANISM
(1) Remove bolts holding shift tower to shift mech-
anism cover and remove tower.
Fig. 3 FILL AND DRAIN PLUGS
1 - PTO COVER
2 - DRAIN BOLT
3 - FILL PLUG
Fig. 4 TRANSFER CASE SHIFTER-TYPICAL
1 - TRANSMISSION
2 - TRANSFER CASE SHIFT MECHANISM
21 - 44 MANUAL TRANSMISSION - NV4500DR
MANUAL TRANSMISSION - NV4500 (Continued)