DODGE TRUCK 1993 Service Repair Manual

21
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NV4500
TRANSMISSION OVERHAUL

•
Fig. 66 Assembling

SPECIAL

Fig. 67 Removing Mainshaft Rear Bearing (23) Remove bearing puller tools.
(24) Remove reverse gear thrust washer (Fig. 68). (25) Remove reverse gear thrust washer locating
pin (Fig. 69). Rear Bearing Puller Tools
REVERSE

GEAR

J922M35
Fig. 68 Reverse Gear Thrust Washer Removal (26) Remove reverse gear and synchro components
as assembly (Fig. 70). It is not necessary to re­
move or disassemble synchro components unless they are damaged and need to be replaced. If synchro sleeve or struts require service, mark
position of sleeve on hub before removal. Cor­
rect sleeve position is important as sleeve can be
installed backwards causing shift problems.
(27) Remove reverse gear bearing assembly from
mainshaft (Fig. 70).

•

NV4500
TRANSMISSION OVERHAUL
21 - 21

Fig.
69
Removing
Thrust Washer Locating Pin (28) Remove reverse gear synchro stop ring and
clutch gear (Fig. 70).
FIRST
REVERSE

Fig.
70
Reverse
Gear, Bearing And
Stop
Ring
Removal
(29) Remove reverse gear bearing spacer from
mainshaft (Fig. 71). (30) Remove first gear snap ring (Fig. 71). Tension
of this snap ring is considerable. Heavy duty snap
ring pliers will be required to spread the ring far enough to remove it.
(31) Remove reverse clutch gear (Fig. 72).
(32) Remove first gear from bearing and mainshaft
(Fig. 73).
(33) Remove first gear bearing from mainshaft
(Fig. 74).

TRANSMISSION
CLEANING AND INSPECTION
Clean the gears, bearings shafts, extension/adapter
housing and gear case with solvent. Dry all parts ex­ cept the bearings with compressed air. Allow the
bearings to either air dry or wipe them dry with clean shop towels.
Fig.
71
Reverse
Gear Bearing
Spacer
And First Gear

Snap
Ring
Removal

J922M51

Fig.
72
Removing
Reverse
Clutch
Gear
FIRST

GEAR
J922M52

Fig.
73
Removing
First Gear
Inspect the reverse idler gear, bearings, shaft and
thrust washers (Fig. 75). Replace the bearings if the
rollers are worn, chipped, cracked, flat-spotted, or

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IV4500
TRANSMISSION
OVERHAUL

•

MAINSHAFT FIRST
SPACER SHAFT J9221-183 Fig.
75
Reverse
idler
Components
brinnelled. Or if the bearing cage is damaged or dis­
torted. Replace the thrust washers if cracked,
chipped, or worn. Replace the gear if the teeth are
chipped, cracked or worn thin.
Inspect the drive gear and bearings (Fig. 76). Mi­
nor scratches and burrs on the gear surfaces can be
reduced with an oil stone and 400 grit paper wetted
with oil. Replace either bearing if worn, or damaged.
Replace the gear if any teeth, splines, or bearing sur­
faces are also worn or damaged.
Inspect the front bearing retainer and bearing cup
(Fig. 77). Replace the bearing cup if scored, cracked,
brinnelled, or rough. Check the release bearing slide surface of the retainer carefully. Minor corrosion, nicks,
or pitting can be smoothed with 400 grit emery and pol­
ished out with crocus cloth. Wet the abrasive paper and
crocus cloth with oil when smoothing/polishing. Replace
the retainer if worn or damaged in any way. Inspect the countershaft and bearings (Fig. 78). Re­
place the bearings if worn, rough, flat spotted, or
heat checked. Check the countershaft gear teeth carefully. Small nicks, scratches, or burrs can be re-
MAINSHAFT FRONT
DRIVE GEAR J9221-181
Fig.
76 Drive Gear
Components

BEARING
OIL
FRONT BEARING CUP SEAL RETAINER
Fig.
77 Front Bearing Retainer
Components

REAR COUNTERSHAFT FRONT J922M84
Fig.
78 Countershaft And
Bearings

moved with an oif stone and 400 grit paper wetted
with oil. However, replace the shaft as an assembly if the forward gear is loose, or any of the teeth are
worn, cracked, broken, or severely chipped.
Be sure to check condition of the countershaft bearing

cups.
Replace either bearings cup if worn, or damaged.

NV4500
TRANSMISSION OVERHAUL
21 - 23
Check condition of the mainshaft. Inspect all the
bearing surfaces, splines and threads. Also check condi­ tion of the snap ring grooves in the hub area and the speedometer drive gear teeth (Fig. 79). Minor scratches
or burrs can be removed with an oil stone and polished
with crocus cloth. However, replace the shaft if any sur­ faces exhibit considerable wear or damage.
GEAR
CASE
BEARING

SURFACES HUB
BEARING
NUT

SURFACES THREADS SPEEDOMETER

TEETH

SPLINES SPLINES SPLINES

J922M85

Fig.
79 Mainshaft Bearing And
Spline
Surfaces
Check condition of the gear case and extension or
adapter housing (Fig. 80). Be sure the alignment dowels
in the case top surface and in the housing/adapter are
tight and in good condition.
Run a tap through the gear case bolt holes if the
threads need minor cleanup. Helicoil inserts can be used to repair seriously damaged threaded holes if nec­
essary.
Be sure all case and housing/adapter sealing and
mating surfaces are free of burrs and nicks. This is especially important as gaskets are not used in the
NV4500. Minor nicks and scratches on the sealing surfaces can be dressed off with a fine tooth file or oil
stone.
Replace the gear case or housing/adapter if cracked
or broken. Do not attempt to repair this type of dam­ age by welding or brazing.
Check condition of the countershaft fifth gear com­
ponents (Fig. 81). This includes the shift lug and rail located in the gear case and the rail bushings.
Inspect the gear and hub assembly. Minor burrs can
be cleaned up with an oil stone. However, the gear and hub assembly should be replaced if the teeth or splines are excessively worn, or damaged. The synchro sleeve
should also be replaced if worn or damaged in any way.
Do not reuse synchro struts that are worn, or springs
that are collapsed or severely distorted. Replace worn distorted synchro parts to avoid shift problems after as­
sembly and installation.
The shift fork should be inspected for evidence of
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 over-
EXTENSION

HOUSING

(2-WHEEL
DRIVE)

ADAPTER

HOUSING
(4-WHEEL
DRIVE)
J9221-186

Fig.
80 Gear
Case
And Extension/Adapter
Housings
size or damaged. Do not attempt to salvage a worn
fork. It will cause shift problems later on. Replace
the shift fork roll pins if necessary, or if doubt exists about their condition.
The bearings should be examined carefully for wear,
roughness, flat spots, pitting, or other damage. Replace
the bearings if necessary.
Inspect the stop ring and clutch gear, replace ei­
ther part if worn or damaged in any way. Also be sure replacement parts fit properly before proceeding
with assembly.
Inspect the 1-2 synchro components (Fig. 82). The hub
weights and retainer springs are reusable if in good condition. However, replace the springs if distorted, or
broken and replace the weights if worn or damaged. Examine the hub and sleeve for wear or damage.
Replace the sleeve and hub if the splines are worn,
chipped or damaged. Replace the synchro struts if worn, or chipped. Also
replace the springs if collapsed, distorted, or broken. Inspect the mainshaft geartrain components (Fig.

83).
Check the teeth on all gears, hubs, clutch gears,
stop rings and clutch rings. The teeth must be in
good condition and not worn, cracked, or chipped. Re­
place any component that exhibits wear or damage. Examine the synchro stop rings, clutch rings and
clutch gears. Replace any part that exhibits wear,
distortion, or damage. Replace the clutch rings if the
friction material is burned, flaking off, or worn. 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. Check condition of the synchro struts and springs.
Replace these parts if worn, cracked, or distorted.

- 24 NV4500
TRANSMISSION OVERHAUL

•
Fig. 82 1-2 Synchro Components

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NV4500
TRANSMISSION
OVERHAUL

• LEGEND FOR

1.
MAINSHAFT
2. FIRST GEAR BEARING

3.
FIRST GEAR

4.
CLUTCH GEAR
5.
SYNCHRO STOP RING

6.
FIRST GEAR SNAP RING
7.
REVERSE
GEAR BEARING SPACER

8.
REVERSE
GEAR BEARING

9.
REVERSE
SYNCHRO SLEEVE

10.
SYNCHRO STRUTS AND SPRINGS
(3
EACH)

11.
REVERSE
GEARLINES
12.
THRUST WASHER
13. THRUST WASHER LOCATING
PIN
14.
MAINSHAFT REAR BEARING

15.
MAINSHAFT REAR BEARING CUP

16.
MAINSHAFT END PLAY SHIMS

17.
MAINSHAFT REAR BEARING PLATE

18.
MAINSHAFT
FIFTH
GEAR

19.
THRUST WASHER

20.
FIFTH
GEAR
NUT

21. MAINSHAFT SPLINE SEAL

22.
CLUTCH GEAR SNAP RING
23. FIRST
SPEED
CLUTCH GEAR

24.
FIRST GEAR SYNCHRO CLUTCH RING
FT GEMRTRAIN
25.
SYNCHRO HUB SNAP RING

26.
FIRST GEAR SYNCHRO STOP RING

27. 1-2
SYNCHRO SLEEVE

28.
SYNCHRO STRUTS AND SPRINGS
(4
EACH)

29.
1
-2
SYNCHRO HUB (INC. RETAINER
SPRINGS
AND WEIGHTS)

30.
SYNCHRO HUB SNAP RING
31. SECOND GEAR SYNCHRO STOP RING

32.
SECOND
SPEED
CLUTCH GEAR
33. SECOND GEAR SYNCHRO CLUTCH RING

34.
CLUTCH GEAR SNAP RING
35.
SECOND GEAR BEARING

36.
SECOND GEAR
37.
THRUST WASHER AND LOCATING
PIN
38.
THRUST WASHER SNAP RING

39.
THIRD
GEAR BEARING SPACER

40.
THIRD
GEAR
41.
THIRD
GEAR BEARING
ASSEMBLIES
(2)
42.
THIRD
GEAR SYNCHRO STOP RING

43.
3-4
SYNCHRO SLEEVE

44.
SYNCHRO STRUTS AND SPRINGS
(3
EACH)

45. 3-4
SYNCHRO HUB
46.
FOURTH
GEAR SYNCHRO STOP RING

47.
FOURTH
SPEED
CLUTCH GEAR

48.
DRIVE GEAR THRUST BEARING

TRANSMISSION
ASSEMBLY
AND ADJUSTMENT
Assembly
Information Gaskets are not used in the NV4500 transmis­

sion.
Use Mopar Gasket Maker, silicone adhe­
sive/sealer, or Loctite 518 on all gear case and
extension housing sealing surfaces.

Adjustment
Specifications
• Countershaft End Play: 0.051-0.15 mm (0.002-
0.006 in.)
• Mainshaft End Play: 0.051-0.15 mm (0.002-0.006 in.)

SPECIAL
TOOL SPECIAL TOOL Fig.
84 Installing Countershaft Front Bearing Cup
J9321-98

GEAR CASE ASSEMBLY (1) Install countershaft front bearing cup in case
with Tool Handle C-4171 and Installer Tool 6061-1 or C-4340 (Fig. 84).
(2) Install new bushings in shift lug rail bores
with Tool 6456 (Fig. 85). Seat bushings flush with

bores.

Fig.
85 Installing Shift Lug Rail
Bushings

(3) If case magnet was removed, install and secure
magnet in clip at bottom of case (Fig. 86).
Fig.
86 Gear
Case
Magnet
Installation

NV450I
TRANSMISSION OVERHAUL
21 - 27
COUNTERSHAFT AND REVERSE IDLER GEAR
INSTALLATION
(1) Install front bearing on countershaft with In­
staller Tool 6446 (Fig. 87).
Fig.
87 Countershaft Front Bearing
installation

(2) Lubricate countershaft front bearing cup and
cone with petroleum jelly.
(3) Position gear case on end with rear of case fac­
ing up (Fig. 88).
(4) Install countershaft in gear case (Fig. 88). Do
not install rear bearing on countershaft rear at
this time.
Fig.
88
Positioning
Countershaft In Gear
Case
(6) Install idler gear front thrust washer on boss in
gear case (Fig. 89). Coat thrust washer with liberal
quantity of petroleum jelly to hold it in place.
POSITION

IDLER

GEAR
Fig.
89
Positioning
Idler Gear Front Thrust
Washer
In
Case
(7) Install reverse idler gear in case (Fig. 90).
(8) Install idler gear rear thrust washer between
idler gear and case boss (Fig. 90).

REAR

THRUST

Fig.
90 Idler Gear And Thrust
Washer
Installation
(9) Align idler gear bearings and thrust washers
with drift. (10) Install reverse idler shaft (Fig. 91). Be sure
notched end of shaft is facing countershaft as shown.
Use shift cover bolt to hold and insert shaft in case

bore.

(11) Lift countershaft upward and position wood
block between front of shaft and case (Fig. 92). (12) Install rear bearing cone on countershaft with
Installer Tool C-4040 or 6446 (Fig. 93).
(13) Remove wood block from under countershaft
and lower countershaft front bearing into front bear­
ing cup. (14) Install new front bearing cap in gear case
(Fig. 94). Apply Mopar silicone adhesive/sealer to (5) Lubricate reverse idler gear bearings with pe­
troleum jelly and install first bearing, bearing spacer and second bearing (Fig. 89).

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N¥4500
TRANSMISSION
OVERHAUL

COUNTERSHAFT
SHIFT

COVER
BOLT
REVERSE

IDLER

SHAFT

Fig.
91
Reverse
idler
Shaft
Installation

WOOD,
BLOCK

J9221-165

COUNTERSHAFT
Fig.
92
Supporting
Countershaft
With
Wood
Block

flange and lip of new cap. Then seat cap in case bore
with wood block and mallet. (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. 95). Tap cup into
place with plastic mallet if necessary.

ADJUSTING
COUNTERSHAFT
END
PLAY
(1) Install countershaft rear bearing plate (Fig.

96).
Be sure plate is seated in notch in reverse idler
shaft before tightening bearing plate bolts.
(2) Rotate countershaft 4-5 times to seat bearings.
(3) Mount dial indicator on case. Then position in­
dicator plunger on end of countershaft and zero indi­
cator dial needle (Fig. 97).
COUNTERSHAFT

SPECIAL

TOOL
6446

REAR

BEARING

_ J9221-166

Fig.
93 Installing Countershaft Rear Bearing
FRONT

BEARING
CAP

(SEAT

WITH

WOOD
BLOCK)
^ , ( /
J9221-172

Fig.
94 Countershaft Front Bearing Cap
Installation
COUNTERSHAFT
REAR

BEARING
CUP

J9221-167

Fig.
95 Countershaft Rear Bearing Cup
Installation
(4) 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.).
(5) Remove countershaft rear bearing plate.
(6) Select and install end play shim that will pro­
vide minimum countershaft end play. Position shim
on rear bearing cup (Fig. 98). (7) Reinstall countershaft rear bearing plate (Fig.

96).
Be sure plate is seated in reverse idler shaft notch before installing bolts. Also be sure end play

•

NV4600 TRANSMISSION OVERHAUL
21 - 29

COUNTERSHAFT
REAR

BEARING
PLATE
IDLER
SHAFT

J9221-168

Fig.
96 Countershaft Rear Bearing
Plate
installation

DIAL
INDICATOR
INDICATOR
MOUNTING
ARM
AND

BASE

J922M69 Fig.
97
Measuring
Countershaft End Play

REAR

BEARING
CUP
END

PLAY
SHIM
(SELECTIVE) Fig.
98 Installing Countershaft End Play
Shim

shims are still in position before tightening bearing
plate bolts. (8) Apply 1-2 drops Mopar Loc N' Seal or Loctite
242 to threads of rear bearing plate bolts. Then in­
stall and tighten bearing plate bolts to 23 Nnn (200
in. lbs.) torque.

SHIFT
LUG AND
RAIL
INSTALLATION
(1) Lubricate shift lug, rail and bushings with Cas-
trol Syntorq. (2) Insert shift lug rail part way into case.
(3) Install shift lug on rail. Note position of
(4) Position shift rail so roll pin notches are at ap­
proximately 5 o'clock position (Fig. 99).
(5) Install roll pin that secures lug to rail (Fig. 99).
NOTCHES

(FOR 5TH GEAR SHIFT FORK ROLL PINS) LUG
RAIL
SHIFT
LUG
J922M71 Fig.
99 Shift Lug And Rail
Installation
MAINSHAFT
AND
GEARTRAIN ASSEMBLY

CAUTION:
The
reverse,
1-2 and 3-4
synchro compo­ nents
can be
assembled
and
installed incorrectly
if

care
is not
exercised. Some components
can be in­

stalled backwards resulting
in
shift problems. Refer
to
the
assembly procedures
for
component
identifi­
cation
and
location.

(1) Lubricate mainshaft bearing surfaces and all
bearing assemblies with Castrol Syntorq or with pe­
troleum jelly.
(2) Install first snap ring in rearmost groove of
mainshaft hub (Fig. 100). This snap ring locates first speed clutch gear on shaft. A total of four of these
snap rings are used to secure various components on
the mainshaft 1-2 synchro hub. The snap rings are all the same size and are interchangeable.
(3) Install first gear bearing assembly on main-
shaft (Fig. 100).
(4) If desired, mainshaft can be placed in upright
(vertical) position and supported with wood blocks
(Fig. 101). Reverse gear components are easier to in­
stall with shaft upright. (5) Install first gear and bearing on shaft (Fig.

101).
Clutch hub side of gear faces front of shaft.