(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 Mopar Silicone Sealer or equivalent to
gear case and housing mating surfaces.
(4) Align and install extension/adapter housing on
gear case (Fig. 129).
(5) Apply Mopar Lock N' Seal or equivalent to
threads of extension/adapter housing bolts.
(6) Install and tighten housing bolts to 54 N´m (40
ft. lbs.).
SHIFT MECHANISM
(1) Clean mating surfaces of shift cover and gear
case with wax and grease remover.
(2) Apply a small amount of Mopar silicone sealer
or equivalent to sealing surface of shift cover.
CAUTION: Do not over-apply an excesive amount
sealer. Excess can squeezed into gear case and
could block lubricant feed holes in time.(3) Lubricate synchro sleeves with CastroltSyn-
torq gear lubricant or equivalent. Then apply light
coat of petroleum jelly to shift fork contact surfaces.
(4) Verify shift fork pads (Fig. 130) are secure.
(5) Verify 1-2 and 3-4 synchro sleeves and forks in
shift cover are in neutral position.
(6) Align and seat shift cover on transmission.
NOTE: If cover will not seat, it may not be aligned
on gear case dowels or shift forks are not aligned
with sleeves and shift lug.
(7) Apply Mopar Lock N' Seal or equivalent to
threads of shift cover bolts.
(8) Install shift cover bolts and tighten to 27-31
N´m (216-276 in. lbs.).
(9) Apply sealer to backup lamp switch. Install
switch into cover and tighten 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.
INSTALLATION
NOTE: If a new transmission is being installed, use
all components supplied with the new transmission.
For example, if a new shift tower is supplied with
the new transmission, do not re-use the original
shift tower.
(1) Apply light coat of Mopar high temperature
bearing grease or equivalent to contact surfaces of
the following components:
²input shaft splines.
²release bearing slide surface of front retainer.
²release bearing bore.
²release fork.
Fig. 129 INSTALLING EXTENSION/ADAPTER
HOUSING
1 - GEAR CASE
2 - EXTENSION HOUSING
Fig. 130 SHIFT FORK PAD
1 - SHIFT FORK PADS
2 - FIFTH-REVERSE FORK
DRMANUAL TRANSMISSION - NV4500 21 - 77
MANUAL TRANSMISSION - NV4500 (Continued)
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 release bearing and clutch disc hub.
(5) Move transmission forward and start input
shaft in release bearing, clutch disc and pilot bush-
ing.
(6) Work transmission forward until seated against
clutch housing. Do not allow transmission to remain
unsupported after input shaft has entered clutch
disc.
(7) Install transmission bolts and tighten to 108
N´m (80 ft. lbs.).
(8) Install transmission mount on transmission or
rear crossmember.
(9) Install rear crossmember.
(10) Remove transmission jack and engine support
fixture.
(11) Position transmission harness wires in clips
on shift cover.
(12) Install clutch slave cylinder and install slave
cylinder shield, if equipped.
(13) Connect speed sensor and backup light switch
wires.
TWO WHEEL DRIVE
(1) Fill transmission with recommended lubricant.
Correct fill level is bottom edge of fill plug hole.
(2) Align and install propeller shaft.
(3) Lower vehicle.
(4) Clean the mating surfaces of shift tower, isola-
tor plate and shift cover with suitable wax and
grease remover.
(5) Apply Mopar Gasket Maker or equivalent to
the sealing surface of the shift cover. Do not over
apply sealant.
(6) Install the isolator plate onto the shift cover,
metal side down.
(7) Install the shift tower onto the isolator plate.
No sealant is necessary between the shift tower and
the isolator plate.
(8) Verify that the shift tower, isolator plate and
the shift tower bushings are properly aligned.
(9) Install the bolts to hold the shift tower to the
isolator plate and the shift cover. Tighten the shift
tower bolts to 10.2-11.25 N´m (7.5-8.3 ft. lbs.).
(10) Install the shift lever extension onto the shift
tower and lever assembly.
(11) Install shift boot and bezel.
(12) Connect battery negative cable.
FOUR WHEEL DRIVE
(1) Install transfer case shift mechanism on trans-
mission.
(2) Install transfer case on transmission jack.
Secure transfer case to jack with safety chains.
(3) Raise jack and align transfer case input gear
with transmission mainshaft.
(4) Move transfer case forward and seat it on
adapter.
(5) Install transfer case nuts and tighten to:
²If 3/8 studs 41-47 N´m (30-35 ft. lbs.).
²If 5/16 studs 30-41 N´m (22-30 ft. lbs.).
(6) Install transfer case shift mechanism to side of
transfer case.
(7) Connect transfer case shift lever to range lever
on transfer case.
(8) Align and connect propeller shafts.
(9) Fill transmission with required lubricant.
Check lubricant level in transfer case and add lubri-
cant if necessary.
(10) Install transfer case skid plate, if equipped
and crossmember. Tighten attaching bolts/nuts to 41
N´m (30 ft. lbs.).
(11) Install exhaust system components.
(12) Lower vehicle.
(13) Clean the mating surfaces of shift tower, iso-
lator plate and shift cover with suitable wax and
grease remover.
(14) Apply Mopar Gasket Maker or equivalent to
the sealing surface of the shift cover. Do not over
apply sealant.
(15) Install the isolator plate onto the shift cover,
metal side down.
(16) Install the shift tower onto the isolator plate.
No sealant is necessary between the shift tower and
the isolator plate.
(17) Verify that the shift tower, isolator plate and
the shift tower bushings are properly aligned.
(18) Install the bolts to hold the shift tower to the
isolator plate and the shift cover. Tighten the shift
tower bolts to 10.2-11.25 N´m (7.5-8.3 ft. lbs.).
(19) Install the shift lever extension onto the shift
tower and lever assembly.
(20) Install shift lever boot and bezel.
(21) Connect battery negative cable.
21 - 78 MANUAL TRANSMISSION - NV4500DR
MANUAL TRANSMISSION - NV4500 (Continued)
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. 131).
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. 132) 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. 133) and Installer.
²Light Duty - Installer 6951
²Heavy Duty - Installer 8161
Fig. 131 Adapter Housing (4±Wheel Drive Models)
1 - ADAPTER HOUSING
2 - SEAL
Fig. 132 EXTENSION HOUSING AND SEAL (4X2)
1 - EXTENSION HOUSING
2 - SEAL
Fig. 133 Extension Housing Bushing
1 - HANDLE
2 - INSTALLER
3 - EXTENSION HOUSING
DRMANUAL TRANSMISSION - NV4500 21 - 83
(2) Install housing seal with Handle C-4171 (Fig.
134) 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 (Fig. 135).(3) Pry up shift mechanism cover at slots provided
in cover (Fig. 136).
(4) Raise cover enough to disengage it from align-
ment dowels in gear case (Fig. 137).
(5) Raise front of shift mechanism cover and lift
cover up and off gear case (Fig. 137).
Fig. 134 Pinion Seal
1 - HANDLE
2 - INSTALLER
Fig. 135 SHIFT MECHANISM BOLTS
1 - SHIFT MECHANISM COVER
2 - BOLTS
Fig. 136 LOOSEN SHIFT MECHANISM
1 - SHIFT MECHANISM COVER SLOT
2-PRYTOOL
Fig. 137 SHIFT MECHANISM COVER
1 - SHIFT MECHANISM COVER
2 - ALIGNMENT DOWELS
21 - 84 MANUAL TRANSMISSION - NV4500DR
EXTENSION HOUSING SEAL (Continued)
FIFTH-REVERSE SHIFT FORK PADS
Three shift pads on the forks are held in place by
tension and a small locating tang (Fig. 138).
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. 139) 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.
(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 Mopar silicone sealer or
equivalent to outer edge of each new plug.
(2) Position each plug in bore and tap into place
with hammer and 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 mechanism
cover and gear case with wax and grease remover.
(2) Apply a small amount of Mopar silicone sealer
or equivalent to sealing surface of shift mechanism
cover.
CAUTION: Do not use an excessive amount sealer.
Excess can squeezed into gear case and could
block lubricant feed holes in time.
(3) Lubricate synchro sleeves with CastroltSyn-
torq gear lubricant or equivalent. Then apply light
coat of petroleum jelly to shift fork contact surfaces.
(4) Verify shift fork pads (Fig. 140) are secure.
(5) Verify 1-2 and 3-4 synchro sleeves and forks in
shift cover are in neutral position.
(6) Align and seat shift mechanism cover on trans-
mission.
NOTE: If cover will not seat, it may not be aligned
on gear case dowels or shift forks are not aligned
with sleeves and shift lug.
Fig. 138 SHIFT FORK PAD LOCATIONS
1 - SHIFT FORK PADS
2 - FIFTH-REVERSE FORK
Fig. 139 EXPANSION PLUG LOCATION
1 - EXPANSION PLUGSFig. 140 SHIFT FORK PAD
1 - SHIFT FORK PADS
2 - FIFTH-REVERSE FORK
DRMANUAL TRANSMISSION - NV4500 21 - 85
SHIFT MECHANISM (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
DRMANUAL TRANSMISSION - NV5600 21 - 89
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
21 - 90 MANUAL TRANSMISSION - NV5600DR
MANUAL TRANSMISSION - NV5600 (Continued)
(8) Remove output shaft ball bearing assembly and
reverse thrust washer from the output shaft (Fig.
21).
(9) Remove reverse gear, reverse gear synchronizer
cone, reverse gear outer blocker ring and reverse
gear bearing (Fig. 22).(10) Remove reverse gear bearing sleeve from the
output shaft (Fig. 23).
NOTE: If necessary heat the sleeve slightly with a
heat gun. Do not use a torch to heat the sleeve or
damage to the output shaft may occur.
(11) Remove roll-pin securing the reverse shift fork
to the reverse shift rail witha6mm(7/32 in.) punch
and hammer.
Fig. 21 OUTPUT SHAFT BEARING AND THRUST
WASHER
1 - OUTPUT SHAFT BALL BEARING
2 - THRUST WASHER
Fig. 22 REVERSE GEAR COMPONENTS
1 - REVERSE GEAR
2 - REVERSE BEARING
3 - BLOCKER RING
4 - FRICTION CONE
Fig. 23 REVERSE BEARING SLEEVE
1 - REVERSE GEAR BEARING SLEEVE
DRMANUAL TRANSMISSION - NV5600 21 - 95
MANUAL TRANSMISSION - NV5600 (Continued)