Chrysler Vehicle User Manual page 1168

TJ
MANUAL - NV3550
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . 31
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
DIAGNOSIS AND TESTING . . . . . . . . . . . . . . . . 31
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . 33
CLEANING . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . . . 42
ASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
MANUAL - NV3550
DESCRIPTION
The NV3550 is a medium-duty, 5-speed, constant
mesh, fully synchronized manual transmission. The
transmission is a four-wheel drive configurations.
The transmission gear case consists of two alumi-
num housings. The clutch housing is a removable
component. It is not an integral part of the transmis-
sion front housing.
A combination of roller and ball bearings are used
to support the transmission shafts in the two hous-
ings. The transmission gears all rotate on caged type
needle bearings. A roller bearing is used between the
input and output shaft.
The NV3550 has a single shaft shift mechanism
with three shift forks all mounted on the shaft. The
shaft is supported in the front and rear housings by
bushings and one linear ball bearing. Internal shift
components consist of the forks, shaft, shift lever
socket and detent components.
The transmission drain plug is located on the bot-
tom and fill plug on the side.
The NV3550 identification and part number bar
code tags (Fig. 1) are located on the top of the trans-
mission, forward of the shift tower.
OPERATION
The driver selects a particular gear by moving the
shift lever to the desired gear position. This move-
ment moves the internal transmission shift compo-
nents to begin the shift sequence. As the shift lever
moves the selected shift rail, the shift fork attached
to that rail begins to move. The fork is positioned in
a groove in the outer circumference of the synchro-
nizer sleeve. As the shift fork moves the synchronizer
sleeve, the synchronizer begins to speed-up or slow
down the selected gear (depending on whether we are
MANUAL - NV3550
TABLE OF CONTENTS
page
INSTALLATION
SPECIFICATIONS
SPECIAL TOOLS
VEHICLE SPEED SENSOR
DESCRIPTION
OPERATION
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
INSTALLATION
1 - PART NUMBER TAG
2 - IDENTIFICATION TAG
3 - FRONT OF REAR HOUSING
up-shifting or down-shifting). The synchronizer does
this by having the synchronizer hub splined to the
mainshaft 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 the friction cone and eventually
will slide over the teeth, locking the gear to the
mainshaft 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.
MANUAL - NV3550
. . . . . . . . . . . . . . . . . . . . . . . . . 64
. . . . . . . . . . . . . . . . . . . . . . . 65
. . . . . . . . . . . . . . . . . . . . . . . 65
. . . . . . . . . . . . . . . . . . . . . . . . . 66
. . . . . . . . . . . . . . . . . . . . . . . . . . . 66
. . . . . . . . . . . . . . . . . . . . . . . . . 67
Fig. 1 NV3550 Identification
21 - 31
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