
(c) Install springs and struts in hub (Fig. 81).
Use lots of petroleum jelly to hold them in place.
Then compress struts with your fingers and move
sleeve upward until struts are started in sleeve.
Verify that struts are engaged in sleeve before pro-
ceeding.
(d) Turn synchro assembly upright. Then move
sleeve into neutral position on hub and work struts
into sleeve at same time. Be sure struts are seated
and springs are not displaced during assembly.(6) Install first gear stop ring in 1-2 synchro hub
and sleeve (Fig. 82). Verify stop ring is seated and
engaged in hub and sleeve.
(7) Install 1-2 synchro assembly and stop ring on
mainshaft with the taper on the sleeve facing for-
ward. (Fig. 83).
(8) Install snap ring that secures 1-2 synchro on
mainshaft hub (Fig. 84). Verify snap ring is seated in
groove in mainshaft hub.
(9) Assemble second gear clutch cone, clutch ring
and stop ring (Fig. 85).
Fig. 80 1-2 Synchro Sleeve On Hub
1 - ALIGN WIDE SLOT IN SLEEVE WITH WIDE SPLINE OF HUB
2 - 1-2 SLEEVE AND HUB
Fig. 81 1-2 Synchro Struts And Springs
1 - WOOD BLOCKS
2 - HUB
3 - SLEEVE
4 - STRUTS AND SPRINGS (4 EACH)
Fig. 82 First Gear Stop Ring In Synchro Hub
Fig. 83 1-2 Synchro
1 - MAINSHAFT HUB
2 - 1-2 SYNCHRO ASSEMBLY
3 - TAPERED SIDE OF SLEEVE
21 - 70 MANUAL - NV4500BR/BE
MANUAL - NV4500 (Continued)

(37) Install fourth gear stop ring in 3-4 synchro
sleeve (Fig. 105).
(38) Install fourth gear clutch gear in stop ring
(Fig. 106).
(39) Roll gear case onto its left side.
(40) Grip mainshaft at pilot bearing hub and just
behind reverse gear. Then lift assembly and guide
rear of shaft through bearing bore at rear of case.
(41) Continue holding front of shaft but switch
grip at rear to shaft output splines. Lift mainshaft
assembly slightly, align gears and seat assembly in
case.
(42) Set transmission case upright (Fig. 107).
(43) Install drive gear thrust bearing on mainshaft
(Fig. 108). Use plenty of petroleum jelly to hold bear-
ing in place.
(44) Check alignment and mesh of mainshaft
gears. If gears are not aligned, roll case on side and
realign shaft and gears in case.DRIVE GEAR AND RETAINER
(1) Install bearing on drive gear with Installer
6448 (Fig. 109).
(2) Lubricate pilot bearing with petroleum jelly
and install it in drive gear bore.
(3) Install drive gear on mainshaft. Work gear
rearward until mainshaft hub is seated in pilot bear-
ing.
(4) Install bearing cup in front retainer with Han-
dle C-4171 and Installer C-4308 (Fig. 110).
(5) Install new oil seal in front bearing retainer
with Installer 6052 (Fig. 111). Use one or two wood
blocks to support retainer as shown. Lubricate seal
lip with petroleum jelly after installation.
(6) Clean contact surfaces of gear case and front
bearing retainer with a wax and grease remover.
Fig. 105 Fourth gear Stop Ring
1 - 3-4 SYNCHRO SLEEVE
2 - FOURTH SPEED STOP RING
Fig. 106 Fourth gear Clutch Gear
1 - FOURTH SPEED CLUTCH GEAR
Fig. 107 Mainshaft And Geartrain In Case
1 - MAINSHAFT AND GEARTRAIN ASSEMBLY
2 - FOURTH SPEED CLUTCH GEAR
Fig. 108 Drive Gear Thrust Bearing
1 - MAINSHAFT
2 - DRIVE GEAR THRUST BEARING
21 - 76 MANUAL - NV4500BR/BE
MANUAL - NV4500 (Continued)

(7) Apply MopartSilicone Sealer or equivalent to
flange surface of front bearing retainer (Fig. 112).
(8) Install front bearing retainer over drive gear
and start it into case.
(9) Start front bearing retainer in gear case. Verify
retainer lube channel is at the top-center(12
O'clock)position (Fig. 112).(10) Align front bearing retainer bolt holes and tap
retainer into place with plastic mallet. Installnew
retainer bolts and tighten to 30 N´m (22 ft. lbs.) (Fig.
113).
NOTE: Never reuse the old bolts.
Fig. 109 Front Bearing On Drive Gear
1 - INSTALLER 6448
2 - BEARING
3 - DRIVE GEAR
Fig. 110 Front Bearing Cup In Retainer
1 - INSTALLER C-4308
2 - HANDLE C-4171
3 - WOOD BLOCKS
4 - RETAINER
Fig. 111 Bearing Retainer Oil Seal
1 - INSTALLER 6052
2 - RETAINER
3 - WOOD BLOCK
Fig. 112 Location Of Front Retainer Lube Channel
1 - LUBE CHANNEL
2 - FRONT RETAINER
3 - APPLY GASKET MAKER HERE
BR/BEMANUAL - NV4500 21 - 77
MANUAL - NV4500 (Continued)

MAINSHAFT END PLAY
(1) Install mainshaft rear bearing cup in case and
over bearing. Tap bearing cup into place with plastic
mallet.
(2) Install rear bearing plate to hold mainshaft
and rear bearing in position (Fig. 114).
NOTE: Do not install any end play shims at this
time.
(3) Tighten rear bearing plate bolts securely.
(4) Place gear case in upright position on bench.
Either cut hole in bench to accept drive gear and
front retainer or use C-clamps to secure transmission
on bench.
NOTE: Do not leave transmission unsupported.
(5) Install Extension Rod 8161 into a suitable
threaded hole in rear of case.
(6) Mount dial indicator on extension rod and posi-
tion indicator plunger against end of mainshaft.
(7) Move mainshaft forward to remove all play
then zero dial indicator.
(8) Move mainshaft upward and record dial indica-
tor reading. Move mainshaft with pry tool positioned
between drive gear and case.
(9) End play should be 0.051-0.15 mm (0.002-0.006
in.). Select fit shims are available to adjust end play.
If end play adjustment is required, remove bearing
plate and install necessary shim.(10) Reinstall rear bearing plate with oil hole in
bearing plate at the top (Fig. 114).
(11) Apply MopartLock N' Seal or equivalent to
bearing plate bolt threads. Install and tighten bolts
to 23 N´m (200 in. lbs.).
(12) Install mainshaft fifth gear with Installer
6446 (Fig. 115). Gear is seated when it contacts rear
bearing.
Fig. 113 Front Bearing Retainer
1 - DRIVE GEAR
2 - FRONT BEARING RETAINER
Fig. 114 Rear Bearing Plate
1 - BEARING PLATE OIL HOLE (AT TOP)
2 - MAINSHAFT REAR BEARING PLATE
Fig. 115 Mainshaft Fifth Gear
1 - MAINSHAFT FIFTH GEAR
2 - INSTALLER 6446
21 - 78 MANUAL - NV4500BR/BE
MANUAL - NV4500 (Continued)

(4) Back the clamp bolt off one full turn.
(5) Place 10-15 drops of LoctiteŸ 272 onto the
mainshaft threads where the fifth gear nut will be
engaged.
(6) Install fifth gear nut on mainshaft (Fig. 125).
(7) There are two splined sockets available to
retain the mainshaft while installing the fifth gear
nut.
²4X2 mainshafts Socket 6993
²4X4 mainshafts Socket 6984
(8) Tighten fifth gear nut as much as possible with
Nut Wrench 6743, long handle ratchet, breaker bar
and applicable socket wrench (Fig. 126).
(9) Lock mainshaft gears by shifting all synchro
sleeves into engaged position.
(10) Tighten fifth gear nut with Nut Wrench 6743
and high capacity torque wrench. Tighten nut to 366-
380 N´m (270-280 ft. lbs.). Have helper hold trans-
mission steady if necessary.
(11) Torque the fifth gear clamp nut clamping bolt
to 13.5 N´m (10 ft. lbs.).
(12) Unlock the mainshaft gears by shifting all
synchro sleeves out of the engaged position.
EXTENSION/ADAPTER HOUSING
(1) Clean mating surfaces of extension/adapter
housing and gear case with a wax and grease
remover.
(2) Check alignment dowels in gear case and hous-
ing or adapter. Be sure dowels are in position and
seated.
(3) Apply MopartSilicone Sealer or equivalent to
gear case and housing mating surfaces.
(4) Align and install extension/adapter housing on
gear case (Fig. 127).
(5) Apply MopartLock N' Seal or equivalent to
threads of extension/adapter housing bolts.(6) Install and tighten housing bolts to 54 N´m (40
ft. lbs.).
(7) Install transfer case, if equipped.
(8) Install engine rear support. Refer to 9 Engine
for procedures.
(9) Install propeller shaft(s).
(10) Remove transmission support stand and lower
vehicle.
Fig. 125 Fifth Gear Nut
1 - FIFTH GEAR
2 - FIFTH GEAR NUTFig. 126 Fifth Gear Nut
1 - WRENCH 6443 OR 6743
2 - FIFTH GEAR NUT
3 - SOCKET 6443 OR 6743
Fig. 127 Extension/Adapter Housing
1 - GEAR CASE
2 - EXTENSION HOUSING
BR/BEMANUAL - NV4500 21 - 81
MANUAL - NV4500 (Continued)

EXPANSION PLUG
The expansion plugs at the rear of the shift rail
bores (Fig. 136) can be replaced if loose and/or leak-
ing.
(1) Drill 6 mm (1/4 in.) diameter hole in center of
each plug to be removed.
(2) Pry plug out of cover with tapered punch.
(3) Clean all chips from shift cover and plug bores.
Then clean plug bores with solvent and dry with
clean shop towel.
INSTALLATION
EXPANSION PLUG
(1) Apply small bead of sealer to outer edge of
each new plug. Use Mopartsilicone adhesive/sealer,
or equivalent.
(2) Position each new plug in bore and tap into
place with hammer and suitable size punch or socket.
FIFTH-REVERSE SHIFT FORK PADS
(1) Align pad locating tab.
(2) Snap pads into place and verify locating tabs
are locked-in.
SHIFT COVER
(1) Clean mating surfaces of shift cover and gear
case with wax and grease remover.
(2) Apply MopartSilicone Sealer, or equivalent, to
sealing surface of shift cover or gear case. Do not
over±apply sealer material. Excess can be squeezed
into gear case and could block lubricant feed holes in
time.
(3) Lubricate synchro sleeves with Castrol Syntorq
gear lubricant. Then apply light coat of petroleum
jelly to shift fork contact surfaces.
(4) Verify that the shift fork pads (Fig. 137) are
properly and securely positioned on the fifth-reverse
fork
(5) Verify that 1-2 and 3-4 synchro sleeves are in
neutral position. Also verify that forks in shift cover
are in neutral position.
(6) Align and install shift cover. If cover will not
seat, it is either not aligned on gear case dowels, or
shift forks are not aligned with sleeves and shift lug.
(7) Apply MopartLock N' Seal, or equivalent, to
threads of shift cover bolts.
(8) Install and tighten shift cover bolts to 27-31
N´m (216-276 in. lbs.).
(9) Install backup lamp switch and gasket in cover.
Apply sealer to switch threads before installation and
tighten switch to 22-34 N´m (193-265 in. lbs.).
(10) Install vent assembly, if removed. Apply an
adhesive/sealer to vent tube to help secure it in cover.
(11) Install transmission.
Fig. 135 Shift Fork Pad Locations
1 - SHIFT FORK PADS
2 - FIFTH-REVERSE FORK
Fig. 136 Expansion Plug Location
1 - EXPANSION PLUGS
Fig. 137 Fifth-Reverse Shift Fork Pads
1 - SHIFT FORK PADS
2 - FIFTH-REVERSE FORK
BR/BEMANUAL - NV4500 21 - 89
SHIFT MECHANISM (Continued)

SHIFT PATTERN
The shift pattern is in a modified H pattern (Fig.
2). Overdrive fifth and sixth gears are in line and
outboard of the first through fourth gear positions.
Reverse gear is to the right of fifth and sixth and for-
ward of the neutral gate.
GEAR RATIOS
GEAR RATIO
FIRST 5.63:1
SECOND 3.38:1
THIRD 2.04:1
FOURTH 1.39:1
FIFTH 1.00:1
SIXTH 0.73:1
REVERSE 5.63:1
IDENTIFICATION
The transmission has two identification tags
attached to the driver side upper clutch housing (Fig.
3).
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 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.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, 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 the friction cone and eventually will slide
over the teeth, locking the gear to the mainshaft, or
countershaft, through the synchronizer.
DIAGNOSIS AND TESTING - MANUAL
TRANSMISSION
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 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 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.
Fig. 2 Shift Pattern
Fig. 3 Identification Tag Location
1 - IDENTIFICATION TAGS
BR/BEMANUAL - NV5600 21 - 93
MANUAL - NV5600 (Continued)

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.
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 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 breakage.
REMOVAL
NOTE: Use a heavy duty scissors style transmis-
sion jack for remove of the transmission.
(1) Disconnect battery negative cable.
(2) Shift transmission into Neutral.
(3) Remove screws attaching shift boot to floorpan.
Then slide boot upward on the shift lever.(4) Remove the bolts holding the shift tower to the
isolator plate and transmission gear case.
(5) Remove the shift tower and isolator plate from
the transmission gear case.
(6) Raise and support vehicle.
(7) Remove skid plate, if equipped.
(8) Mark propeller shaft/shafts and axle yokes for
installation reference.
(9) Remove propeller shaft.
(10) Disconnect and remove exhaust system as
necessary.
(11) Disconnect wires at backup light switch.
(12) Support engine with adjustable safety stand
and wood block.
(13) If transmission is to be disassembled for
repair, remove drain bolt at bottom of PTO cover and
drain lubricant from transmission (Fig. 4).
(14) Remove clutch slave cylinder splash shield, if
equipped.
(15) Remove clutch slave cylinder bolts and move
cylinder aside for clearance.
(16) Remove wire harness from clips on transmis-
sion.
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.
(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.
Fig. 4 NV5600 Drain Bolt
1 - PTO COVER
2 - DRAIN BOLT
21 - 94 MANUAL - NV5600BR/BE
MANUAL - NV5600 (Continued)