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The NV4500 transmission is a heavy duty 5 speed
overdrive transmission. The 4500 is readily adapted to many
vehicles that originally were equipped with light duty 5 speeds,
3 speed manual transmissions, 4 speed manual transmissions or
automatic transmissions. The transmission has a cast iron
main case, large gears and weighs approximately 200 pounds.
NV4500 transmissions are original equipment on both Dodge and GM
vehicles up to one ton. The transmission was introduced during
the 1992 model year and still remains in production.
Manual
transmission to manual transmission conversions usually require
at least a new bellhousing and clutch lever. For most
applications a new transmission mount, clutch assembly and
transmission to transfer case adapter will also be required.
Modifications to the crossmember, floor pan, driveshafts, and
exhaust system are needed for some applications. Parts
costs for the basic adapter kits start at about $350 with an
average cost of about $650 plus the cost of the
transmission.
Automatic to NV4500 conversions are generally much more
expensive due to the numerous additional parts you will need.
Figure on a new flywheel, flywheel bolts, clutch assembly,
clutch bolts, bellhousing, clutch fork, clutch release system,
clutch pedal, brake pedal, transmission mount, transfer case
linkage, and hardware. You will need to cut the cab
floor/carpet to accept the shift tower, rewire the backup lights
and cruise control. Late model vehicles may require major
electrical changes including changing the engine computer.
In most cases you will also need to have driveline modifications
done. Some models will also require crossmember and/or
exhaust fabrication and/or relocation. Body lifts or
cab floor alterations may be needed for clearance. Unless
you have a donor truck to cannibalize most or all the parts
from, this is usually one expensive conversion. NV4500
conversions for gas engine trucks will typically run from
$3500-$5,000 for all new parts including the transmission.
BUYING A USED TRANSMISSION
Well
over 1 million NV4500 transmissions have been produced so
finding a used unit is not all that difficult. Some of
these can be save you big bucks over the cost of a
new transmission,
however, you can really get burned unless you buy wisely.
First
is the transmission you are looking at even compatible with the
proposed conversion? NV4500s' were built for numerous
applications. That great deal on e-Bay may take extensive
modification to fit your application or require a total rebuild.
Two
wheel drive transmissions are generally less expensive then 4x4
models. However to convert one of these to most 4x4
applications will require at least changing the mainshaft and
tailshaft housing.
Dodge
and GM were the primary users of the NV4500. Early GM
units differ from all other by having a wider gear ratio and
different bellhousing bolt pattern and index diameter.
Dodge transmissions have longer input shafts, but shorter output
shafts. Early GM and all Dodge applications used external
clutch slave cylinders, while later GM transmissions had a
internal concentric slave cylinder.
Any
transmission with 150,000 miles or more is almost certainly due
for a major overhaul which should include bearings, seals,
synchronizer rings, and small parts.
Kits are available with and
without tools for those who wish to do a rebuild themselves.
For a professional rebuild, beware of the rebuilder who uses
imported aftermarket parts. While some of these parts are
OK, many are not worth a hoot. We got badly burned by
major import parts like
mainshafts and small parts like shift fork pads. Many rebuilders
also substitute lower rated wheel bearings in place of the
premium original equipment bearing numbers. In any case, a
complete, quality, professional rebuild will most likely run
$1,000 or more.
Most
used transmissions do not come with a shift lever which can run
as high as $100. Some don't even have shift towers which
will cost another $100 plus.
So
beware of that great deal on a used (or rebuilt) NV4500 until
you thoroughly check the facts.
TWO
SPEED auxiliary OVERDRIVE transmissions
If you
have a Ford, Chevy, GMC, Jeep, or Toyota with a 4 speed
transmission and you want to add overdrive, a cheaper and more
versatile option is to install a Ranger 7" long, two speed auxiliary
transmission between the bellhousing and transmission. A
reliable and heavy-duty unit with both direct drive and a 27%
overdrive. Will convert your 4 speed to an 8 speed.
Allows you to "split" gears and is ideal for trailer towing
applications. Lowers engine rpm 27% in overdrive for
improved fuel economy, less engine wear, and reduced engine
noise. Contact
advanceadapters.com
Driveshaft modification are required. Crossmember must be
relocated 7" back. Floor modifications required.
Transfer case shifter mount must be fabricated.
 Two
Speed Auxiliary transmission fits between the bellhousing and
transmission. It weighs about 80 lbs, is rated for 420 ft-lbs.
of torque and can be used on vehicles with Gross Combined
Vehicle Weights of up to 25,000 lbs. |
