GEAR CASE
(1) Remove countershaft front bearing cap with
hammer (Fig. 40).
(2) Remove countershaft front bearing cup with
Remover 6454 and Handle C-4171 (Fig. 41).(3) Remove roll pin that secures shift lug on shift
rail in case (Fig. 42). A small pin punch can be mod-
ified by putting a slight bend in it to drive pin com-
pletely out of shift rail (Fig. 42).
(4) Remove shift lug rail.
Fig. 40 COUNTERSHAFT FRONT BEARING CAP
1 - HAMMER
2 - BEARING CAP
Fig. 41 COUNTERSHAFT FRONT BEARING CUP
1 - REMOVER
2 - HANDLE
Fig. 42 SHIFT LUG ROLL PIN
1 - PUNCH
2 - 30É BEND
3 - PIN PUNCH MODIFICATION
4 - SHIFT LUG
5 - SHIFT RAIL
DRMANUAL TRANSMISSION - NV4500 21 - 55
MANUAL TRANSMISSION - NV4500 (Continued)
(14) Remove wood block from under countershaft
and lower countershaft front bearing into front bear-
ing cup.
(15) Lubricate countershaft rear bearing cup and
cone with petroleum jelly.
(16) Install countershaft rear bearing cup in gear
case and over rear bearing (Fig. 72). Tap cup into
place with plastic mallet if necessary.
(17) Install countershaft rear bearing plate (Fig.
73).
NOTE: Verify plate is seated in notch in reverse
idler shaft before tightening bearing plate bolts.(18) Apply Mopar silicone adhesive/sealer or equiv-
alent to flange and lip of new cap. Installnewfront
bearing cap in gear case (Fig. 74) with Handle
C-4171 and Installer C-3972-A.
COUNTERSHAFT END PLAY
(1) Rotate countershaft 4-5 times to seat bearings.
(2) Mount dial indicator on case. Then position
indicator plunger on end of countershaft and zero
dial indicator (Fig. 75).
(3) Raise countershaft with screwdriver and note
end play reading on dial indicator. End play should
be 0.051 - 0.15 mm (0.002 - 0.006 in.).
Fig. 72 COUNTERSHAFT REAR BEARING CUP
1 - COUNTERSHAFT REAR BEARING CUP
Fig. 73 COUNTERSHAFT REAR BEARING PLATE
1 - COUNTERSHAFT
2 - REAR BEARING PLATE
3 - IDLER SHAFT
Fig. 74 COUNTERSHAFT FRONT BEARING CAP
1 - FRONT BEARING CAP
Fig. 75 MEASURING COUNTERSHAFT END PLAY
1 - DIAL INDICATOR
2 - COUNTER SHAFT
3 - INDICATOR MOUNTING ARM AND BASE
DRMANUAL TRANSMISSION - NV4500 21 - 65
MANUAL TRANSMISSION - NV4500 (Continued)
(5) Install new oil seal in front bearing retainer
with Installer 6052 (Fig. 112). 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.
(7) Apply Mopar Silicone Sealer or equivalent to
flange surface of front bearing retainer (Fig. 113).
(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. 113).(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.
114).
NOTE: Never reuse the old bolts.
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. 115).
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. 115).
(11) Apply Mopar Lock N' Seal or equivalent to
bearing plate bolt threads. Install and tighten bolts
to 23 N´m (200 in. lbs.).
Fig. 112 BEARING RETAINER OIL SEAL
1 - INSTALLER
2 - RETAINER
3 - WOOD BLOCK
Fig. 113 LOCATION OF FRONT RETAINER LUBE
CHANNEL
1 - LUBE CHANNEL
2 - FRONT RETAINER
3 - APPLY GASKET MAKER HERE
Fig. 114 FRONT BEARING RETAINER
1 - DRIVE GEAR
2 - FRONT BEARING RETAINER
DRMANUAL TRANSMISSION - NV4500 21 - 75
MANUAL TRANSMISSION - NV4500 (Continued)
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.
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 bushing.
(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 - 80 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. 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)
MANUAL TRANSMISSION - NV5600
TABLE OF CONTENTS
page page
MANUAL TRANSMISSION - NV5600
DESCRIPTION.........................88
OPERATION...........................90
DIAGNOSIS AND TESTING................90
REMOVAL.............................90
DISASSEMBLY.........................91
CLEANING - TRANSMISSION.............106
INSPECTION.........................106
ASSEMBLY...........................106
INSTALLATION........................121
SPECIFICATIONS - NV5600..............123SPECIAL TOOLS.......................123
ADAPTER HOUSING SEAL
REMOVAL............................128
INSTALLATION........................128
EXTENSION HOUSING SEAL
REMOVAL............................128
INSTALLATION........................128
SHIFT COVER
REMOVAL............................129
INSTALLATION........................129
MANUAL TRANSMISSION -
NV5600
DESCRIPTION
The NV5600 is a six speed constant mesh manual
transmission (Fig. 1). All gear ranges including
reverse are synchronized. First and second gears uti-
lize dual cone synchronizers in order to aid shifting.
Sixth gear is an overdrive range. The transmission
uses cast iron for the gear case and extension/
adapter housing and aluminum for the clutch hous-
ing.To drain the trans remove the bottom PTO cover
bolt. Fill the trans through the plug to the rear of the
PTO cover (Fig. 1). Dry fill is approximately 4.5 liters
(9.5 pints) or to the bottom edge of the fill plug hole.
The gear ratios are: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
21 - 88 MANUAL TRANSMISSION - NV5600DR
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)