
(17) Remove reverse gear and needle bearing (Fig.
46).
REVERSE IDLER
(1) Remove idler gear snap rings (Fig. 47).
(2) Remove thrust washer, wave washer, thrust
plate and idler gear from shaft.
(3) Remove idler gear needle bearing from shaft.
CLEANING
Clean the gears, shafts, shift components and
transmission housings with a standard parts clean-
ing solvent. Do not use acid or corrosive base sol-
vents. Dry all parts except bearings with compressed
air.
Clean the shaft bearings with a mild solvent such
as Mopar degreasing solvent, Gunk or similar sol-
vents. Do not dry the bearings with compressed air.
Allow the bearings to either air dry or wipe them dry
with clean shop towels.
INSPECTION
SHIFT LEVER ASSEMBLY
The shift lever assembly is not serviceable. Replace
the lever and shift tower as an assembly if the tower,
lever, lever ball or internal components are worn or
damaged.
SHIFT SHAFT AND FORKS
Inspect the shift fork interlock arms and synchro
sleeve contact surfaces (Fig. 48). Replace any fork
exhibiting wear or damage in these areas. Do not
attempt to salvage shift forks.
Check condition of the shift shaft detent plunger
and spring. The plunger should be smooth and free of
nicks or scores. The plunger spring should be
straight and not collapsed, or distorted. Minor
scratches or nicks on the plunger can be smoothed
with 320/400 grit emery soaked in oil. Replace the
plunger and spring if in doubt about condition. Check
condition of detent plunger bushings. Replace if dam-
aged.
Inspect shift shaft, shift shaft bushing, bearing,
shaft lever and lever bushing that fits over the lever.
Replace shaft if bent, cracked or severely scored.
Minor burrs, nicks or scratches can be smoothed off
with 320/400 grit emery cloth followed by polishing
with crocus cloth. Replace the shift shaft bushing or
bearing if damaged.
Replace the shaft lever and bushing if either part
is deformed, or worn. Do not attempt to salvage these
parts as shift fork binding will occur. Replace the roll
pin that secures the lever to the shaft.
Fig. 47 Reverse Idler Components
1 - SNAP RING
2 - FLAT WASHER
3 - WAVE WASHER
4 - THRUST WASHER
5 - REVERSE IDLER GEAR6 - IDLER GEAR BEARING
7 - IDLER SHAFT
8 - THRUST WASHER
9 - SNAP RING
10 - THRUST WASHER LOCKBALLS
Fig. 46 REVERSE GEAR & NEEDLE BEARING
1 - REVERSE GEAR AND NEEDLE BEARING
DRMANUAL TRANSMISSION - NV3500 21 - 15
MANUAL TRANSMISSION - NV3500 (Continued)

FRONT/REAR HOUSINGS AND BEARING
RETAINERS
Inspect the housings carefully. Look for cracks,
stripped threads, scored mating surfaces, damaged
bearing bores or worn dowel pin holes. Minor nicks
on mating surfaces can be dressed off with a fine file
or emery cloth. Damaged threads can be renewed by
either re-tapping or installing Helicoil inserts.
NOTE: The front housing contains the countershaft
front bearing race. The rear housing contains the
countershaft rear bearing race. These components
are NOT serviceable items. The front housing will
have to be replaced if the countershaft bearing race
is loose, worn or damaged. The rear housing will
have to be replaced if the countershaft rear bearing
race is loose, worn or damaged.
Inspect the input shaft bearing retainer. Be sure
the release bearing slide surface of the retainer is in
good condition. Minor nicks on the surface can be
smoothed off with 320/420 grit emery cloth and final
polished with oil coated crocus cloth. Replace the
retainer seal if necessary.
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.
Fig. 48 Shift Forks And Shaft
1 - SHIFT SHAFT
2 - SHAFT LEVER
3 - SHAFT LEVER BUSHING4 - 3-4 SHIFT FORK
5 - 1-2 SHIFT FORK
6 - FIFTH-REVERSE SHIFT FORK
21 - 16 MANUAL TRANSMISSION - NV3500DR
MANUAL TRANSMISSION - NV3500 (Continued)

MANUAL TRANSMISSION - NV4500
TABLE OF CONTENTS
page page
MANUAL TRANSMISSION - NV4500
DESCRIPTION.........................42
OPERATION...........................42
DIAGNOSIS AND TESTING................43
REMOVAL.............................43
DISASSEMBLY.........................44
CLEANING............................60
INSPECTION..........................60
ASSEMBLY............................61
INSTALLATION.........................77
SPECIFICATIONS.......................79
SPECIAL TOOLS.......................79ADAPTER HOUSING SEAL
REMOVAL.............................83
INSTALLATION.........................83
EXTENSION HOUSING SEAL
REMOVAL.............................83
INSTALLATION.........................83
SHIFT MECHANISM
REMOVAL.............................84
INSTALLATION.........................85
SHIFT COVER
REMOVAL.............................86
INSTALLATION.........................86
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
21 - 42 MANUAL TRANSMISSION - NV4500DR

(21) Install Puller 6444 on the puller rods and
secure with nuts (Fig. 59). Tighten puller bolt to the
remove bearing.
(22) Remove bearing puller tools and rear main-
shaft bearing from output shaft.
(23) Remove reverse gear thrust washer (Fig. 60).
(24) Remove reverse gear and synchro components
as assembly (Fig. 61).CAUTION: Do not disassemble synchro compo-
nents unless they are damaged. If synchro sleeve
or struts require service, mark position of sleeve on
hub before removal. Correct sleeve position is
important as sleeve can be installed backwards
causing shift problems.
(25) Remove reverse gear bearing assembly from
mainshaft (Fig. 61).
(26) Remove reverse gear bearing spacer from
mainshaft (Fig. 62).
(27) Remove reverse clutch gear snap ring (Fig.
62). Heavy duty snap ring pliers will be required to
spread the ring far enough to remove it.
Fig. 59 MAINSHAFT REAR BEARING
1-JAWS
2 - COLLAR
3 - FLANGE
4 - MAINSHAFT
5 - PULLER
6 - TIGHTENING WRENCH
7 - HOLDING WRENCH
8 - RODS
Fig. 60 REVERSE GEAR THRUST WASHER
1 - REVERSE GEAR
2 - THRUST WASHER
Fig. 61 REVERSE GEAR, BEARING, AND STOP
RING
1 - FIRST GEAR
2 - REVERSE GEAR ASSEMBLY
3 - BEARING ASSEMBLY
4 - STOP RING
Fig. 62 REVERSE GEAR BEARING SPACER AND
FIRST GEAR SNAP RING
1 - CLUTCH GEAR SNAP RING
2 - REVERSE GEAR BEARING SPACER
DRMANUAL TRANSMISSION - NV4500 21 - 59
MANUAL TRANSMISSION - NV4500 (Continued)

(3) Install snap ring on mainshaft 1-2 synchro hub
to secure clutch cone (Fig. 81). Verify snap ring is
seated in hub groove and against clutch cone.
(4) Support mainshaft in upright position to install
remaining gears, snap rings and synchro compo-
nents. Shaft can be supported in gear case or hole
can be cut in workbench to support shaft.
(5) If 1-2 synchro hub and sleeve were disassem-
bled for service, reassemble hub, sleeve, struts and
springs as follows:
(a) Align and install sleeve on hub. Rotate sleeve
until it slides onto hub. Sleeve only fits one way
and will easily slide onto hub when long slot in
sleeve, aligns with long shoulder on hub (Fig. 82).
(b) Place wood blocks under hub that will raise
hub about 3.5 cm (1.375 in.) above surface of work-
bench. Then allow sleeve to drop down on hub (Fig.
83).
(c) Install springs and struts in hub (Fig. 83).
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.
Fig. 81 FIRST GEAR CLUTCH CONE SNAP RING
1 - FIRST GEAR CLUTCH CONE
2 - MAINSHAFT 1-2 SYNCHRO HUB
3 - CLUTCH CONE SNAP RING
Fig. 82 1-2 SYNCHRO SLEEVE ON HUB
1 - ALIGN WIDE SLOT IN SLEEVE WITH WIDE SPLINE OF HUB
2 - 1-2 SLEEVE AND HUB
Fig. 83 1-2 SYNCHRO STRUTS AND SPRINGS
1 - WOOD BLOCKS
2 - HUB
3 - SLEEVE
4 - STRUTS AND SPRINGS (4 EACH)
DRMANUAL TRANSMISSION - NV4500 21 - 65
MANUAL TRANSMISSION - NV4500 (Continued)

(20) Install synchro stop ring on third gear (Fig.
97). Verify stop ring is seated on cone taper.
(21) If 3-4 synchro was disassembled for service,
reassemble synchro components as follows:
(a) Align and install synchro sleeve on hub (Fig.
98).Front side of hub has a narrow groove
machined in it.
(b) Insert all three synchro struts in slots
machined in sleeve and hub (Fig. 98).
(c) Install and seat synchro springs (Fig. 98).
Use screwdriver to compress springs and seat them
in struts and hub as shown.(22) Start 3-4 synchro assembly on mainshaft with
the hub groove and sleeve groove both facing for-
ward. Tap assembly onto shaft splines until hub is
about 3 mm (0.125 in.) away from third gear stop
ring. Then align stop ring with synchro sleeve and
hub and seat synchro assembly with Installer C-4040
(Fig. 99).
(23) Verify 3-4 synchro hub is seated on shaft with
approximately 3 mm (0.125 in.) of shaft spline visi-
ble.
NOTE: If hub is not seated, stop ring lugs are mis-
aligned. Rotate ring until lugs are engaged in 3-4
hub slots.
(24) Verify that second and third gear rotate freely
at this point. If not, determine the cause and correct.
(25) Invert mainshaft in case or bench.
(26) Install first gear bearing on mainshaft.
(27) Install first gear on shaft with clutch hub side
of gear facing the front of shaft (Fig. 100). Verify tabs
on clutch ring are aligned and seated in first gear
hub.
NOTE: 1-2 synchro hub will not seat properly if
clutch ring tabs are misaligned.
Fig. 97 THIRD GEAR STOP RING
1 - SYNCHRO STOP RING
2 - THIRD GEAR
Fig. 98 SYNCHRO ASSEMBLY (3-4)
1 - STRUT (3)
2 - SPRING (3)
3 - 3-4 SLEEVE
4 - 3-4 HUB
Fig. 99 SEATING 3-4 SYNCHRO ASSEMBLY ON
MAINSHAFT
1 - 3-4 SYNCHRO HUB
2 - HUB GROOVE
3 - INSTALLER C-4040
DRMANUAL TRANSMISSION - NV4500 21 - 69
MANUAL TRANSMISSION - NV4500 (Continued)

(28) Install reverse clutch gear on first gear (Fig.
100). Verify clutch gear is seated on shaft splines.
(29) Install reverse clutch gear snap ring with
heavy duty snap ring pliers (Fig. 100). Verify snap
ring is seated in groove.
NOTE: Reverse gear will not fit properly if snap ring
is not seated.
(30) Install stop ring on clutch cone (Fig. 101). Ver-
ify stop ring is seated on cone taper.
(31) Install reverse gear bearing spacer on main-
shaft and seat against reverse clutch gear snap ring
(Fig. 102).
(32) Install reverse gear bearing on mainshaft
(Fig. 102).
(33) If reverse gear sleeve and struts were disas-
sembled for service, reassemble sleeve, struts and
springs as follows:
CAUTION: The reverse sleeve will fit either way on the
hub. Verify tapered side of the sleeve faces rearward.
(a) Position sleeve on hub so tapered side of
sleeve faces rearward. (Fig. 103).
(b) Rotate sleeve to align teeth on sleeve and
hub. Sleeve will slide easily into place on hub when
properly aligned.
(c) Install springs in gear hub (Fig. 103). Use
petroleum jelly to hold springs in place if desired.
(d) Compress first spring with flat blade screw-
driver and slide strut into position in hub slot.
Then work spring into seat in strut with small
hooked tool or screwdriver.
Fig. 103 REVERSE GEAR SYNCHRO ASSEMBLY
1 - REVERSE GEAR
2 - SLEEVE
3 - SPRING (3)
4 - STRUT (3)
5 - HUB
Fig. 100 FIRST GEAR AND CLUTCH GEAR
1 - FIRST GEAR
2 - REVERSE CLUTCH GEAR SNAP RING
3 - REVERSE CLUTCH GEAR
Fig. 101 CLUTCH GEAR STOP RING
1 - REVERSE GEAR STOP RING
2 - CLUTCH GEAR
3 - FIRST GEAR
Fig. 102 REVERSE GEAR BEARING AND SPACER
1 - REVERSE GEAR BEARING
2 - BEARING SPACER
3 - FIRST GEAR
21 - 70 MANUAL TRANSMISSION - NV4500DR
MANUAL TRANSMISSION - NV4500 (Continued)

Test Four - Transmission In Reverse
This test checks pump output, pressure regulation
and the front clutch and rear servo circuits. Use 300
psi Test Gauge C-3293-SP for this test.
(1) Leave vehicle on hoist and leave gauge C-3292
in place at accumulator port.
(2) Move 300 psi Gauge C-3293-SP back to rear
servo port.
(3) Have helper start and run engine at 1600 rpm
for test.
(4) Move transmission shift lever four detents
rearward from full forward position. This is Reverse
range.
(5) Move transmission throttle lever fully forward
then fully rearward and note reading at Gauge
C-3293-SP.
(6) Pressure should be 145 - 175 psi (1000-1207
kPa) with throttle lever forward and increase to 230 -
280 psi (1586-1931 kPa) as lever is gradually moved
rearward.
Test Five - Governor Pressure
This test checks governor operation by measuring
governor pressure response to changes in vehicle
speed. It is usually not necessary to check governor
operation unless shift speeds are incorrect or if the
transmission will not downshift. The test should be
performed on the road or on a hoist that will allow
the rear wheels to rotate freely.
(1) Move 100 psi Test Gauge C-3292 to governor
pressure port.
(2) Move transmission shift lever two detents rear-
ward from full forward position. This is D range.
(3) Have helper start and run engine at curb idle
speed. Then firmly apply service brakes so wheels
will not rotate.
(4) Note governor pressure:
²Governor pressure should be no more than 20.6
kPa (3 psi) at curb idle speed and wheels not rotat-
ing.
²If pressure exceeds 20.6 kPa (3 psi), a fault
exists in governor pressure control system.
(5) Release brakes, slowly increase engine speed,
and observe speedometer and pressure test gauge (do
not exceed 30 mph on speedometer). Governor pres-
sure should increase in proportion to vehicle speed.
Or approximately 6.89 kPa (1 psi) for every 1 mph.
(6) Governor pressure rise should be smooth and
drop back to no more than 20.6 kPa (3 psi), after
engine returns to curb idle and brakes are applied to
prevent wheels from rotating.
(7) Compare results of pressure test with analysis
chart.Test Six - Transmission In Overdrive Fourth Gear
This test checks line pressure at the overdrive
clutch in fourth gear range. Use 300 psi Test Gauge
C-3293-SP for this test. The test should be performed
on the road or on a chassis dyno.
(1) Remove tachometer; it is not needed for this
test.
(2) Move 300 psi Gauge to overdrive clutch pres-
sure test port. Then remove other gauge and reinstall
test port plug.
(3) Lower vehicle.
(4) Turn OD switch on.
(5) Secure test gauge so it can be viewed from
drivers seat.
(6) Start engine and shift into D range.
(7) Increase vehicle speed gradually until 3-4 shift
occurs and note gauge pressure.
(8) Pressure should be 469-496 kPa (68-72 psi)
with closed throttle and increase to 620-827 kPa (90-
120 psi) at 1/2 to 3/4 throttle. Note that pressure can
increase to around 896 kPa (130 psi) at full throttle.
(9) Return to shop or move vehicle off chassis
dyno.
PRESSURE TEST ANALYSIS CHART
TEST CONDITION INDICATION
Line pressure OK during any
one testPump and regulator valve
OK
Line pressure OK in R but
low in D, 2, 1Leakage in rear clutch area
(seal rings, clutch seals)
Pressure low in D Fourth
Gear RangeOverdrive clutch piston
seal, or check ball problem
Pressure OK in 1, 2 but low
in D3 and RLeakage in front clutch area
Pressure OK in 2 but low in
R and 1Leakage in rear servo
Front servo pressure in 2 Leakage in servo; broken
servo ring or cracked servo
piston
Pressure low in all positions Clogged filter, stuck
regulator valve, worn or
faulty pump, low oil level
Governor pressure too high
at idle speedGovernor pressure solenoid
valve system fault. Refer to
diagnostic book.
Governor pressure low at all
mph figuresFaulty governor pressure
solenoid, transmission
control module, or governor
pressure sensor
Lubrication pressure low at
all throttle positionsClogged fluid cooler or
lines, seal rings leaking,
worn pump bushings,
pump, clutch retainer, or
clogged filter.
Line pressure high Output shaft plugged, sticky
regulator valve
Line pressure low Sticky regulator valve,
clogged filter, worn pump
21 - 142 AUTOMATIC TRANSMISSION - 46REDR
AUTOMATIC TRANSMISSION - 46RE (Continued)