(6) Drive out shift bushing and lever roll pin with
a hammer and punch (Fig. 17).
NOTE: Use proper size punch to avoid bending the
shift shaft.
(7) Pull shift shaft straight out of rear housing,
shift socket, fifth-reverse fork and 1-2 fork (Fig. 18).
(8) Remove shift socket from rear housing (Fig.
19).
(9) Remove shaft lever and bushing (Fig. 20).
(10) Rotate 3-4 fork around synchro sleeve until
fork clears shift arms on 1-2 and fifth-reverse forks,
then remove 3-4 fork (Fig. 21).
Fig. 17 SHIFT SHAFT LEVER & BUSHING ROLL PIN
1 - PIN PUNCH
2 - BUSHING AND LEVER
3 - SHIFT SHAFT
Fig. 18 SHIFT SHAFT
1 - SHIFT SHAFT
2 - 3-4 FORK
3 - SHAFT DETENT NOTCHES
Fig. 19 SHIFT SOCKET & ROLL PIN
1 - SHAFT BORE
2 - ROLL PIN
3 - SHIFT SOCKET
Fig. 20 SHIFT SHAFT LEVER & BUSHING
1 - SHAFT LEVER AND BUSHING
2 - 3-4 FORK
Fig. 21 3-4 SHIFT FORK
1 - 3-4 FORK
2 - 1-2 AND 5TH-REVERSE FORK ARMS
3 - 3-4 SYNCHRO SLEEVE
21 - 8 MANUAL TRANSMISSION - NV3500DR
MANUAL TRANSMISSION - NV3500 (Continued)
REAR HOUSING - 2WD
(1) On 2-wheel drive transmission, remove three
bolts that attach output shaft bearing retainer to
rear case (Fig. 25). Bolts are rear of shift tower open-
ing.
(2) Tap rear housing upward and off output shaft
bearing with a plastic/rawhide hammer (Fig. 26).
(3) Lift rear housing up and off geartrain (Fig. 27).
Fig. 26 SEPARATE REAR HOUSING & OUTPUT
SHAFT BEARING
1 - REAR HOUSING
2 - MALLET
3 - FIXTURE
Fig. 27 REAR HOUSING - 2WD
1 - REAR HOUSING
2 - SHIFT FORKS AND GEARTRAIN
Fig. 25 OUTPUT SHAFT
1 - OUTPUT SHAFT BEARING RETAINER BOLTS (THIRD BOLT
IS AT OPPOSITE SIDE OF CASE)
21 - 10 MANUAL TRANSMISSION - NV3500DR
MANUAL TRANSMISSION - NV3500 (Continued)
(11) Remove output shaft bearing snap ring (Fig.
41).
(12) On 2-wheel drive models, remove output shaft
bearing.
(13) Remove fifth gear (Fig. 42).(14) Remove fifth gear needle bearing. Spread
bearing just enough to clear shoulder on output shaft
(Fig. 43).
(15) Remove fifth-reverse synchro hub snap ring
(Fig. 44).
Fig. 41 OUTPUT SHAFT BEARING SNAP RING
1 - OUTPUT SHAFT BEARING
2 - BEARING SNAP RING
3 - SNAP RING PLIERS
Fig. 42 FIFTH GEAR
1 - FIFTH GEAR AND SYNCHRO RING
Fig. 43 FIFTH GEAR NEEDLE BEARING
1 - FIFTH GEAR NEEDLE BEARING
Fig. 44 FIFTH-REVERSE SYNCHRO HUB SNAP
RING
1 - FIFTH-REVERSE SYNCHRO HUB AND SLEEVE
2 - SYNCHRO HUB SNAP RING
3 - SNAP RING PLIERS
21 - 14 MANUAL TRANSMISSION - NV3500DR
MANUAL TRANSMISSION - NV3500 (Continued)
Inspect output shaft bearing retainer, the
U-shaped retainer must be flat and free of distortion.
Replace the retainer if the threads are damaged or if
the retainer is bent or cracked.
COUNTERSHAFT BEARINGS AND RACES
The countershaft bearings and races are machine
lapped during manufacture to form matched sets.
The bearings and races should not be interchanged.
NOTE: The bearing races are a permanent press fit
in the housings and are NOT serviceable. If a bear-
ing race becomes damaged, the front or rear hous-
ing must be replaced. A new countershaft bearing
will be supplied with each new housing for service
use.
REVERSE IDLER COMPONENTS
Inspect the idler gear, bearing, shaft, thrust
washer, wave washer and thrust plate. Replace the
bearing if any of the needle bearing rollers are worn,
chipped, cracked, flat-spotted or brinnelled. Also
replace the bearing if the plastic bearing cage is
damaged or distorted.
Replace thrust washer, wave washer or thrust
plate if cracked, chipped or worn. Replace idler gear
if the teeth are chipped, cracked or worn thin.
Replace shaft if worn, scored or the bolt threads are
damaged beyond repair. Replace support segment if
cracked or chipped and replace the idler attaching
bolts if the threads are damaged.
Shift Socket
Inspect the shift socket for wear or damage.
Replace the socket if the roll pin or shift shaft bores
are damaged. Minor nicks in the shift lever ball seat
in the socket can be smoothed down with 400 grit
emery or wet/dry paper. Replace the socket if the ball
seat is worn or cracked. Do not reuse the original
shift socket roll pin. Install anewpin during assem-
bly. The socket roll pin is approximately 33 mm
(1-1/4 in.) long.
Output Shaft And Geartrain
Inspect all gears for worn, cracked, chipped or bro-
ken teeth. Also check condition of the bearing bore in
each gear. The bores should be smooth and free of
surface damage. Discoloration of the gear bores is a
normal occurrence and is not a reason for replace-
ment. Replace gears only when tooth damage has
occurred or if the bores are brinnelled or severely
scored.
Inspect the shaft splines and bearings surfaces.
Minor nicks on the bearing surfaces can be smoothed
with 320/420 grit emery and final polished with cro-
cus cloth. Replace the shaft if the splines are dam-aged or bearing surfaces are deeply scored, worn or
brinnelled.
ASSEMBLY
NOTE: Sealers are used at all case joints. Use
Mopar Gasket Maker or equivalent for all case joints
and Mopar silicone sealer or equivalent for the
input shaft bearing retainer.
SYNCHRONIZER
(1) Slide sleeve onto the hub, leaving enough room
to install the spring in the hub and strut in the hub
groove.
(2) Install first spring in the hub, then install a
strut over the spring. Verify spring is seated in the
spring bore in the strut.
(3) Slide sleeve onto the hub far enough to hold
the first strut and spring in place.
(4) Place detent ball in the top of the strut, then
press the ball into place with a small screwdriver.
Work the sleeve over the ball to hold it in place.
(5) Repeat procedure for the remaining springs,
struts and balls. Use tape or rubber bands to tempo-
rarily secure each strut and ball as they are
installed.
(6) Verify the synchro three springs, struts and
detent balls are all in place (Fig. 49).
Fig. 49 SYNCHRONIZER COMPONENTS
1 - SLEEVE
2 - HUB SHOULDER
3 - SPRING (3)
4 - STRUT (3)
5 - DETENT BALL (3)
6 - HUB
DRMANUAL TRANSMISSION - NV3500 21 - 17
MANUAL TRANSMISSION - NV3500 (Continued)
(8) Install front thrust washer on shaft and slide
washer up against gear and over lock ball (Fig. 80).
(9) Install wave washer, flat washer and remain-
ing snap ring on idler shaft (Fig. 80). Verify snap
ring is seated.
SHIFT SHAFT AND DETENT PLUNGER BUSHINGS/
BEARINGS
(1) Inspect shift shaft bushing and bearing for
damage.
(2) If necessary, the shift shaft bushing can be
replaced as follows:
(a) Locate a bolt that will thread into the bush-
ing without great effort.
(b) Thread the bolt into the bushing, allowing
the bolt to make its own threads in the bushing.
(c) Attach a slide hammer or suitable puller to
the bolt and remove bushing.(d) Use the short end of Installer 8119 to install
the new bushing.
(e) Bushing is correctly installed if flush with
the transmission case.
(3) If necessary, the shift shaft bearing can be
replaced as follows:
(a) Locate a bolt that will thread into the bear-
ing without great effort.
(b) Thread the bolt into the bearing as much as
possible.
(c) Attach a slide hammer or suitable puller to
the bolt and remove the bearing.
(d) Use the short end of Installer 8119 to install
the new bearing.
(e) Bearing is correctly installed if flush with the
transmission case.
(4) Inspect detent plunger bushings for damage.
NOTE: The detent plunger bushings are installed to
a specific depth. The space between the two bush-
ings when correctly installed contain an oil feed
hole. Do not attempt to install the bushings with
anything other than the specified tool or this oil
hole may become restricted.
(5) If necessary, the detent plunger bushings can
be replaced as follows:
(a) Using the long end of Installer 8119, drive
the detent bushings through the outer case and
into the shift shaft bore.
(b) Remove the bushings from the shift shaft
bore.
(c) Install a new detent plunger bushing on the
long end of Installer 8118.
(d) Start bushing in the detent plunger bore in
the case.
(e) Drive bushing into the bore until the tool
contacts the transmission case.
(f) Install a new detent plunger bushing on the
short end of Installer 8118.
(g) Start the bushing in the detent plunger bore
in the case.
(h) Drive bushing into the bore until the tool
contacts the transmission case.
Fig. 80 IDLER GEAR & SHAFT ASSEMBLY
1 - REAR OF SHAFT
2 - GEAR
3 - THRUST WASHER AND BALL
4 - WAVE WASHER
5 - FLAT WASHER
6 - FRONT OF SHAFT
7 - SNAP RING
8 - SNAP RING
21 - 26 MANUAL TRANSMISSION - NV3500DR
MANUAL TRANSMISSION - NV3500 (Continued)
(11) On 2-wheel drive transmission, thread one
Alignment Pin 8120 in center or passenger side hole
of output shaft bearing retainer. Then position
retainer on fifth gear as shown (Fig. 88).
(12) Assemble 1-2 and fifth reverse-shift forks (Fig.
89). Arm of fifth-reverse fork goes through slot in 1-2
fork.
(13) Install assembled shift forks in synchro
sleeves and verify forks are seated in sleeves (Fig.
90).
REAR HOUSING - 2WD
NOTE: Transmission shift components must be in
Neutral position to prevent damaging the synchro
and shift components when installing the housings.(1) Drive adapter housing alignment dowels back
into housing until dowels are flush with mounting
surface (Fig. 91).
Fig. 88 ALIGN OUTPUT SHAFT BEARING RETAINER
1 - ALIGNMENT PIN
2 - OUTPUT SHAFT BEARING RETAINER
Fig. 89 1-2 & FIFTH-REVERSE SHIFT FORKS
1 - 1-2 FORK
2 - 1-2 FORK ARM
3 - FIFTH-REVERSE FORK
Fig. 90 SHIFT FORKS IN SYNCHRO
1 - SYNCHRO SLEEVES
2 - FORK ARMS
3 - SHIFT FORKS
Fig. 91 REAR HOUSING DOWELS
1 - HOUSING ALIGNMENT DOWELS
2 - REAR HOUSING
3 - DOWEL FLUSH WITH SURFACE
DRMANUAL TRANSMISSION - NV3500 21 - 29
MANUAL TRANSMISSION - NV3500 (Continued)
(12) Install shift shaft bushing lock bolt (Fig. 117).
Apply Mopar Gasket Maker or equivalent to bolt
threads, shank and underside of bolt head before
installation.
CAUTION: If lock bolt cannot be fully installed the
shift shaft is not in Neutral, or the shaft bushing (or
lever) is misaligned.
(13) Lubricate then install shift shaft detent
plunger in housing bore. Lubricate plunger with
semi-synthetic/synthetic grease. Verify plunger is
fully seated in detent notch in shift shaft.
(14) Install detent spring inside plunger.
(15) Install detent plug in end of Installer 8123.
Position plug on detent spring and compress spring
until detent plug pilots in detent plunger bore. Drive
detent plug into transmission case until plug seats.
(16) Install backup light switch (Fig. 118).
(17) Install input shaft snap ring (Fig. 119).
(18) Installnewoil seal in front bearing retainer
with Installer 6448 (Fig. 120).(19) Apply bead of Mopar silicone sealer or equiv-
alent to flange surface of front bearing retainer (Fig.
121).
Fig. 117 SHAFT LOCK BOLT
1 - SHIFT SHAFT LOCK BOLT
2 - SHAFT SOCKET
Fig. 118 BACKUP LIGHT SWITCH
1 - BACKUP LIGHT SWITCH
Fig. 119 SHAFT SNAP RING - TYPICAL
1 - INPUT SHAFT SNAP RING
Fig. 120 BEARING RETAINER OIL SEAL
1 - INSTALLER
2 - FRONT BEARING RETAINER
Fig. 121 SEAL BEARING RETAINER - TYPICAL
1 - APPLY SEALER BEAD
2 - INPUT SHAFT BEARING RETAINER
DRMANUAL TRANSMISSION - NV3500 21 - 37
MANUAL TRANSMISSION - NV3500 (Continued)
MANUAL TRANSMISSION - NV4500
TABLE OF CONTENTS
page page
MANUAL TRANSMISSION - NV4500
DESCRIPTION.........................43
OPERATION...........................43
DIAGNOSIS AND TESTING................44
REMOVAL.............................44
DISASSEMBLY.........................46
CLEANING............................62
INSPECTION..........................62
ASSEMBLY............................63
INSTALLATION.........................80
SPECIFICATIONS.......................81
SPECIAL TOOLS.......................81ADAPTER HOUSING SEAL
REMOVAL.............................85
INSTALLATION.........................85
EXTENSION HOUSING SEAL
REMOVAL.............................85
INSTALLATION.........................85
SHIFT MECHANISM
REMOVAL.............................86
INSTALLATION.........................87
SHIFT COVER
REMOVAL.............................87
INSTALLATION.........................87
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
DRMANUAL TRANSMISSION - NV4500 21 - 43