(8) Assemble and install fifth synchro clutch gear
and stop ring in fifth gear hub (Fig. 124). Verify
parts are seated in fifth gear hub.
(9) Install clutch gear snap ring (Fig. 125).
(10) Align roll pin holes in shift fork with notches
in shift lug rail. Then install roll pins from top side
of fork (Fig. 122).
NOTE: Roll pins only fit one way due to small
shoulder at one end of each pin.
FIFTH GEAR NUT
(1) Install belleville washer onto the mainshaft.
(2) Install fifth gear nut over the mainshaft.
(3) Tighten the clamp bolt until the gap in the
clamp nut assembly is closed.
(4) Back the clamp bolt off one full turn.(5) Place 10-15 drops of Loctite 272 onto the main-
shaft threads where the fifth gear nut will be
engaged.
(6) Install fifth gear nut on mainshaft (Fig. 126).
(7) Hold mainshaft Socket 6993 4X2 or Socket
6984 4X4 while installing the fifth gear nut.
(8) Tighten fifth gear nut as much as possible with
Wrench 6743, long handle ratchet, breaker bar and
applicable socket wrench (Fig. 127).
(9) Lock mainshaft gears by shifting all synchro
sleeves into engaged position.
Fig. 124 FIFTH SYNCHRO CLUTCH GEAR AND
STOP RING
1 - STOP RING
2 - CLUTCH GEAR
Fig. 125 FIFTH SYNCHRO CLUTCH SNAP RING
1 - CLUTCH GEAR RING
2 - FIFTH SYNCHRO CLUTCH GEAR
Fig. 126 FIFTH GEAR NUT
1 - FIFTH GEAR
2 - FIFTH GEAR NUT
Fig. 127 FIFTH GEAR NUT
1 - WRENCH
2 - FIFTH GEAR NUT
3 - SOCKET
21 - 78 MANUAL TRANSMISSION - NV4500DR
MANUAL TRANSMISSION - NV4500 (Continued)
(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. 128).
(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. 129) 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.
Fig. 128 INSTALLING EXTENSION/ADAPTER
HOUSING
1 - GEAR CASE
2 - EXTENSION HOUSING
Fig. 129 SHIFT FORK PAD
1 - SHIFT FORK PADS
2 - FIFTH-REVERSE FORK
DRMANUAL TRANSMISSION - NV4500 21 - 79
MANUAL TRANSMISSION - NV4500 (Continued)
(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. 138) 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.
(7) Apply Mopar Lock N' Seal or equivalent to
threads of shift cover bolts.
(8) Install shift cover mechanism 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.
(11) Install transmission.
SHIFT COVER
REMOVAL
(1) Shift transmission into Neutral.
(2) Unscrew and remove the shift lever extension
from the shift
(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 shift cover.
(5) Remove the shift tower and isolator plate from
the transmission shift cover.
INSTALLATION
(1) Clean the mating surfaces of shift tower, isola-
tor plate and shift cover with suitable wax and
grease remover.
(2) Apply Mopar Gasket Maker or equivalent to
the sealing surface of the shift cover. Do not over
apply sealant.
(3) Install the isolator plate onto the shift cover,
metal side down.
(4) Install the shift tower onto the isolator plate.
No sealant is necessary between the shift tower and
the isolator plate.
(5) Verify shift tower, isolator plate and shift tower
bushings are properly aligned.
(6) Install bolts to hold the shift tower to the iso-
lator plate and the shift cover. Tighten the shift
tower bolts to 10.2-11.25 N´m (7.5-8.3 ft. lbs.).
(7) I
nstall shift lever extension, shift boot and bezel.
Fig. 137 EXPANSION PLUG LOCATION
1 - EXPANSION PLUGS
Fig. 138 SHIFT FORK PAD
1 - SHIFT FORK PADS
2 - FIFTH-REVERSE FORK
DRMANUAL TRANSMISSION - NV4500 21 - 87
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
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)
(6) Remove primary shift rail detent plunger (Fig.
9).
(7) Remove clutch housing bolts (10) (Fig. 10) from
inside the housing.(8) Remove shift rail blocker bolt (Fig. 11) from the
side of the transmission gear case.
EXTENSION/ADAPTER HOUSING
(1) Remove bolts holding the extension/adapter
housing onto the transmission gear case.
(2) Remove extension/adapter housing from the
transmission gear case with Puller 8244 (Fig. 12).
NOTE: It may be necessary to straighten the housing
during removal due to the tendency for the reverse
idler shaft to bind into one side of the housing.
Fig. 9 PRIMARY SHIFT RAIL DETENT PLUNGER
1 - DETENT PLUNGER
Fig. 10 CLUTCH HOUSING BOLTS
1 - BOLTS (10)
Fig. 11 SHIFT RAIL BLOCKER BOLT
1 - BLOCKER BOLT
Fig. 12 TRANSMISSION CASE PULLER
1 - PULLER
2 - EXTENSION/ADAPTER HOUSING
DRMANUAL TRANSMISSION - NV5600 21 - 93
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
21 - 96 MANUAL TRANSMISSION - NV5600DR
MANUAL TRANSMISSION - NV5600 (Continued)
(5) Remove input shaft oil guide and retainer seal
(Fig. 50).
CLEANING - TRANSMISSION
Clean the gears, bearings shafts, extension/adapter
housing and gear case with solvent. Dry all parts
except the bearings with compressed air. Allow the
bearings to either air dry or wipe them dry with
clean shop towels.
INSPECTION
NOTE: Minor corrosion, nicks, or pitting can be
smoothed with 400 grit emery and polished out with
crocus cloth.
Inspect the reverse idler gear, bearings, shaft and
thrust washers. Replace the bearings if the rollers
are worn, chipped, cracked, flat-spotted or brinnelled.
Replace the gear if the teeth are chipped, cracked or
worn thin.
Inspect the front bearing retainer and bearing cup.
Replace the bearing cup if scored, cracked, brinnelled
or rough. Check the release bearing slide surface of
the retainer carefully. Replace the retainer if worn or
damaged in any way.
Inspect mainshaft bearing surfaces, splines, snap
ring grooves and threads. Replace the shaft if any
surfaces exhibit considerable wear or damage.
Inspect the countershaft and bearings. Replace the
shaft if any surfaces exhibit considerable wear or
damage.Inspect shift forks for wear and distortion. Check
fit of the sleeve in the fork to be sure the two parts
fit and work smoothly. Replace the fork if the roll pin
holes are worn oversize or damaged. Do not attempt
to salvage a worn fork. Replace shift fork roll pins if
necessary or if doubt exists about their condition.
The all bearings for wear, roughness, flat spots,
pitting or other damage. Replace the bearings if nec-
essary.
Inspect the blocker rings and fiction cones. replace
either part if worn or damaged in any way. Replace if
the friction material is burned, flaking off or worn.
Inspect synchro components wear or damage.
Replace parts if worn, cracked or distorted.
Inspect all of the thrust washers and locating pins.
Replace the pins if bent or worn. Replace the wash-
ers if worn or the locating pin notches are distorted.
Inspect the case and housing/adapter sealing and
mating surfaces are free of burrs and nicks. Inspcet
the alignment dowels in the case top surface and in
the housing/adapter are tight and in good condition.
Replace the gear case or housing/adapter if cracked
or broken.
ASSEMBLY
NOTE: Gaskets are not used in the transmission.
Use Mopar Gasket Maker or equivalent on all gear
case and extension housing sealing surfaces.
OUTPUT SHAFT
(1) Place second gear on bench with the synchro
clutch ring up.
(2) Install second gear synchro inner blocker ring
onto second gear (Fig. 51).
Fig. 50 OIL GUIDE AND SEAL
1 - INPUT SHAFT OIL GUIDE
2 - INPUT SHAFT OIL SEAL
Fig. 51 INNER BLOCKER RING
1 - INNER BLOCKER RING
2 - GEAR
21 - 106 MANUAL TRANSMISSION - NV5600DR
MANUAL TRANSMISSION - NV5600 (Continued)