Dodge RAM 1500 1998 Owner's Manual page 1746

DR
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 . . . . . . . . . . . . . . . . . . . . . . . 81
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.
MANUAL TRANSMISSION - NV4500
TABLE OF CONTENTS
MANUAL TRANSMISSION - NV4500
page
ADAPTER HOUSING SEAL
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
INSTALLATION
EXTENSION HOUSING SEAL
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
INSTALLATION
SHIFT MECHANISM
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
INSTALLATION
SHIFT COVER
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
INSTALLATION
Fig. 1 IDENTIFICATION TAG LOCATION
1 - PTO COVER
2 - I.D. TAG
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.
. . . . . . . . . . . . . . . . . . . . . . . . . 85
. . . . . . . . . . . . . . . . . . . . . . . . . 85
. . . . . . . . . . . . . . . . . . . . . . . . . 87
. . . . . . . . . . . . . . . . . . . . . . . . . 87
21 - 43
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