|We offer a Brand New Dodge HD Diesel and GM NV4500.
The NV4500 transmission is generally considered to be the
most robust and reliable 5 speed transmission ever supplied in pickup trucks
(up to 1 Ton) It is a popular replacement in older trucks with 4
speeds. It is also a popular replacement for 5 speed transmissions used in
other 1 ton trucks, such as the Ford ZF or the Getrag (as used in Dodge
Diesels before Dodge went to the NV4500). It is also the most popular truck
5 speed to be used in building up extreme Jeeps, Broncos and other hard core
short wheelbase off road vehicles.
High Impact focuses on having QUALIFIED technical support
readily available to customers both in engineering their specific
NV4500 conversion systems, as well tech support both during and following the system
NV4500 Conversion Packages we have available
Conversion Packages Available (click on link below)
ratio NV4500 applications
Applications for 6.34 ratio NV4500s
are available in rebuild unit only. Price is $1,250 + $500 core charge.
Contact us for
applications you do not find listed!
Impact offers custom engineered conversion packages. Complete NV4500
installation packages are available for MANY vehicles. These include
needed Bellhousing or adapter, any needed clutch components, transfer
case adapters. Transmissions are custom configured with correct
input/output shaft as is optimum for the application.
The fine print: As
for "is it 100% Bolt-in", yes, all the components should
bolt together fine. However, I would never consider or assume
any installation of a transmission that did not come in the
vehicle was going to be 100% bolt in: 1. Might work out that way. 2.
Most cases have a few issues you will need to figure out on the fly.
3. Occasionally there is some issue we did not anticipate that turns
out to be a
hassle. That is rare. In any event, our customer service is always available
to help you resolve whatever issues may arise in your conversion. Our
Tech Support is generally quite a bit more knowledgeable than the
average Joe you get on the line!
into the following links for package pricing:
(Applies to the 5.61
Turnkey system installation
We do NOT have a Jeep or 4x4 shop ourselves and do
not work directly on customer vehicles. We do in many instances work with install shops, and
even have several we have worked with a lot and can sub install work to
for customers desiring our knowledge and engineering of the system while
wanting a complete turnkey install done professionally.
Recommendations regarding shops to do custom
work for you
I want to make a general observation, and like all general
observations, there will be exceptions. However: An Auto repair
business and a custom fabrication or 4WD shop are two very different
businesses. The repair business is involved in diagnosis and repair of
stock vehicles. They quote and work jobs out of references such as
MOTOR'S MANUAL. Custom 4x4 and fab shops specializing in doing things
to vehicles that DID NOT come that way from the factory. I know, there
are a lot of guys competent to do either, but rarely do I see one shop
that operates efficiently or well doing one when it is set up
primarily to do the other.
thus: TAKE CUSTOM WORK TO A SHOP THAT MAKES IT THEIR PRIMARY
BUSINESS TO DO CUSTOM WORK. If you cannot find the job listed in
MOTOR'S MANUAL consider it custom work.
Generally speaking, when you purchase one of our engineered
packages: You will be supplied with the primary ingredients to install
a NV4500 in your vehicle. The following are the main items to
Drive Shaft Modifications
In many conversions, the overall length of the installed
transmission will be different than the current transmission,
resulting in the need to modify your driveshafts. If you measure the
overall length of your drivetrain from the engine block back to the
mounting surface of the transfer case (in 4WD vehicles) or the
driveshaft yoke (in 2WD vehicles), it is then easy enough to add up
the components of the NV4500 package to go in. (Bellhousing, BH
adapter [if any], NV4500 main case, transfer case adapter [4wd] or 2WD
tailhousing. From this you can determine accurately whether driveshaft
modifications will be needed. Such driveshaft modifications can
usually be performed by a local driveshaft shop. Typical cost of such
mods are $2-250.
Crossmember location and/or modification: Most vehicles have a
crossmember (or in some Jeeps, the skidplate) supports the rear of the
driveline. It is usually located under the transmission tailhousing or
4WD transfer case adapter. (Some vehicles use bellhousing as to
frame mounts as a rear drivetrain support). In most cases the stock
crossmember will work with some modification. You can get a pretty
good idea of what is involved here by looking at your existing
crossmember and comparing it to the following description of what an
NV4500 likes to see:
NV4500 crossmember is located about 14" from the front of the
transmission (which on gas engines is about 7" from the rear of
the engine block when using a Dodge input NV4500 or 6.5 inches when
using a GM input NV4500). If yours will need to move, it is frequently
possible to simply unbolt the crossmember, move it forward or back,
re-drilling the frame at the desired location and bolting in place. An NV4500 crossmember must pass below and be the transmission
tailhousing or 4WD transfer case adapter. This tailhousing or adapter
is then bolted to the crossmember via a rubber or urethane isolation
mount. We have several different mount kits we supply in conversion
packages to facilitate this.
In some popular conversions where they are useful, we offer
crossmember/skidplate adapter kits and/or complete replacement
crossmembers as a part of our conversion packages.
In most cases, skidplate equipped vehicles will simply need some
minor drilling and such to mount the NV4500.
IF your existing crossmember proves unsuitable, and a
pre-fabricated replacement is not available, you will need to
fabricate a new crossmember. This generally involves cutting, welding
and drilling steel tube, angle and/ or channel into a suitable shape,
and bolting this into the vehicle. You will need suitable pieces of
steel, a cut-off saw, electric drill and a welder. Estimate 2-3 hours
to fabricate a crossmember.
Shifter Location and Stick Lever modifications
The shifter stick on an NV4500 comes up roughly 9.5" from the
front of the transmission. There is a short stub on the transmission,
and the shifter lever (extension handle) attaches to and is removable
Take a look at where your current shifter stick comes up. If the
location is different, it may prove to require a different
location for the hole in the floorboards for the stick to come up
through. If this is the case, It will be necessary to measure and cut
a new hole in the floor in the appropriate location. The old hole may
be patched using a piece of sheet metal cut to size to cover the old
hole, and attached to the floor pan by sheet metal screws or pop
rivets. We recommend using silicon sealant glue (RTV) to seal this and
Factory shifter sticks come in different lengths and shapes. Many
transmissions had the shifter stick located forward on the transmission
case. This necessitated snaking the shifter lever back out from under
the dash, and then bending up. The NV4500 shifter will typically come
up to the rear of the dash, in clear space. In any case, we supply a
simple steel shifter stick that is easy to heat and re-bend if the
shape does need to be changed. (Factory NV4500 sticks incorporate
rubber in their design, and cannot be heated and reformed.
All NV4500s are equipped with an electric back-up switch. This switch
closes when the transmission is in reverse. If you desire to use this
switch to operate back-up lights, you will need the correct
connector-pigtail. This part is GM PN 12085485 or 14014559 or AC Delco
#PT107. The GM switch will fit the Dodge trans. TIP: When replacing a
Getrag with an NV4500 on a Dodge Cummins, the Getrag b/u switch will
fit the NV4500, and will thus still work with the existing electrical
Bellhousing and clutch:
The NV4500 has a bolt pattern that is unique to the NV4500. When
converting from a different transmission, an adapter plate or
replacement bellhousing will always be needed. In some cases the
conversion is based around an adapter plate attached to a factory
bellhousing (such as in Ford applications). In other cases a different
bellhousing will be required (sometimes an off the shelf factory
bellhousing is used, however in many cases a custom or an aftermarket
"conversion" bellhousing will be used, making the job
simpler and less costly.
In some cases, both methods are available, and pros and cons can be
weighed. The main advantage of the adapter plate method is that
usually the stock clutch and clutch linkage can be retained as-is. The
main advantage of the replacement bellhousing method is it will be
1" shorter (which matters really only in short wheelbase vehicles
where every inch counts), or in the simple fact of having fewer parts
in the stack up.
Clutch: As mentioned above, when using an adapter plate, the
existing clutch and clutch linkage will usually work as-is. It is of
course recommended to replace the clutch disc, pressure plate and
throwout bearing if they are not fresh. In the case of a conversion
bellhousing, in many cases the stock parts will still work. We have
tried to mention in the specific packages whether stock components may
be retained. Where stock components will not work, we have specified
suitable replacements as part of the conversion package.
Clutch Linkages: Considerations putting later systems into older
Our conversion packages will typically supply
a replacement pilot bearing suitable for the conversion in question.
2WD tailhousing/speedometer hookup
Our NV4500s can be supplied with several different output
configurations. Depending on what is in your vehicle, and your requirements,
one or the other may be superior. We will go over his with you at the
time of purchase, and determine which is optimal. The possibilities
Tailhousing with a fixed yoke (available configured for GM
electronic vehicle speed sensor (VSS), or blank, for axle mounted VSS).
13" tailhousing with a slip-yoke (Available configured for
mechanical speedo, electronic vehicle speed sensor (VSS), or blank,
for axle mounted VSS)
Notes: Mechanical speedo drive components needed: Dodge
Speedo Gear Applcations
4WD Adapter housing and output shaft
There are three factory configurations available. Depending on what
transfer case you desire to mate the NV4500 to, and what vehicle
you are putting it all into, different configurations would be
optimal. We will go over these factors with you at the time of
purchase to determine what is optimal for YOUR conversion. General
assumptions are made in the published packages, assuming stock Tcase
for the vehicle in question.
No extra cost" Options include
Factory GM tailhousing with 32 spline output shaft
Factory Dodge tailhousing with 23 spline output shaft
Factory Dodge tailhousing with 29 spline output shaft
Extra Cost options include:
Aftermarket transfer case adapters (for use where a factory NV4500
setup will not work with your transfer case. We have a wide variety of
these available. A full list can be found on the "4WD transmission
- transfer case adapters" page.
Dodge style Cast Iron 4WD tailhousing: A direct replacement for the
aluminum part used on Dodge transmissions.
Installation Difficulty Disclaimer:
While every attempt has been made to make this as straight forward
a conversion as possible, please realize you are bolting a transmission
into your vehicle that is other than than the one it came with. You
must expect a certain amount of ingenuity and "make-it-fit"
to be required. We realize this is part of any conversion: Our tech
support is always available to go over any technically difficulties
you may encounter. And you will find us to be considerably more knowledgeable
than the usual joe you get on the line.
The package we use for that application will bolt the NV4500 to the
stock Ford bellhousing via an adapter plate. The adapter plate is
1" thick. The NV4500 main case is 12.375" long. The
tailhousing is 6.25", and the adapter to the Ford Tcase is
1.650". You could compare these numbers with the parts that are
Conversions from an Automatic
entail all of the above general conversion information. In addition,
you will need a flywheel and clutch components. If the package in
question uses a bellhousing adapter plate, a Factor bellhousing will
be needed. We have variations of all of our conversion packages to
supply all of these components.
pedal and linkage:
most cases it is easiest to bolt in the clutch linkage from your year
and model truck with a stick trans. We can supply master and slave
cylinders. The actual pedal assembly, and any mechanical linkages, are
either dealer items (in later model trucks) or junkyard items. We have
not found it practical to supply these items: These are pretty much
the only parts you will be on your own with. In some cases it is
practical to modify a pedal assembly out a different truck to work.
Advance Adapters carry a line of generic clutch pedal assemblies that
may work. These we can supply. In any event, we can discuss your
specific application and make suggestions and include any parts we can
supply into the package.
Clutch Linkages: Considerations putting later systems into older
converting from auto to stick on computer controlled vehicles
1992 Dodge and General Motors trucks started appearing in showrooms
with one of the most versatile transmissions ever to be offered in a
production truck: the New Venture Gear 4500. General Motors
applications include it as an option in 3/4 and 1-ton full size
trucks. Dodge standard duty units come in trucks with the 5.2
and 5.9 liter engine, while Dodge HD versions are used with Cummins
diesels and V10’s.
transmission is a fully synchronized (except reverse on GM models)
five-speed gearbox with all of the strength and low-gear benefits (and
then some) of the older granny four-speeds, with a 27-percent
overdrive. The cast iron case is combined with massive gear sets in an
almost compact 200lb package. This unit shifts with a smooth, short
action and very distinct shift gates. We consider it the premium
manual trans swap for 4x4 vehicles.
production Dodge NV4500 and GM NV4500 share the same gear ratios.
Early GM units (93-94) were built with a lower first gear ratio of
6.34 to 1.0. These low-geared GM boxes have since been discontinued
and are generally much more difficult to obtain. We are able to
provide new and remanufactured NV4500s with these early
in 95’, all GM units were built with the same gear ratios as the
GM; 93/up Dodge
Pounds of Torque
|4WD Adapter Housing
||30 spl Slip yoke
||31 spl Slip yoke
|Input shaft stickout
|Input shaft spline
Bearing Retainer Specification
|GM NV4500 1993-95
|GM NV4500 1996 and up
||none: Int Slave Cyl
|Dodge NV4500 Standard Duty
|Dodge NV4500 Heavy Duty
Bearing Race GM 96-up, and all Dodge Std Duty retainer: GM retainer is for internal slave and dodge retainer is for ext slave, but they will both fit NV4500s GM 96-up, and ALL Dodge std duty Dodge HD is a Different retainer.
GM 92-95 NV4500 uses a bearing retainer with a smaller outside diameter, and a smaller bolt circle, and is not
interchangeable with the other NV4500s.
All NV4500s use the same bearing race EXCEPT GM 96-up. This parts should be
replaced when a new tapered roller bearing is installed.
Tapered Roller Bearing
All NV4500s use the same tapered roller bearing. When changing shafts, however it is extremely difficult to get this part off the old shaft without damage, and thus is
the input seal is the same on ALL NV4500s. This part sis hard to remove from one retainer and put in another and should be replaced when
changing the retainer.
Bellhousing Bolt Pattern:
GM 1993-1995 10.078 across the top, 10.394 across the bottom,
GM 1996 + up 10.078 across the top, 9.738 across the
bottom, 6.043 vertically
Dodge (All) 10.078 across
the top, 9.738 across the bottom, 6.043 vertically
Shifter Stub Specification
The NV4500 shifter will have a short stub sticking up from the top
cover, There are 3 different methods by which a shifter extension
Dodge NV4500 1993-1999 A short, square stub sticks up
Dodge NV4500 1999-up Threaded stub, 12mm x 2.0 pitch threads
Threaded stub, 14mm x 1.5 pitch threads
You MUST use the correct synthetic lubricant. The GM part no. for the
correct oil is 12346190 (quart). The Dodge part number for the same
oil is 4874459 Use of ANY other oil in the NV4500 will lead to failure and also voids
any chance of a warranty claim.
Additional Info: Here is the response to an inquiry
that was sent to Castrol USA about where to get Castrol Syntorq in
Europe: "Castrol TAF-X 75W-90 GL-4 gear oil is made in the U.K.
and sold only in Europe. However, the equivalent in the
is Syntorq LT. Having said that, Syntorq LT SAE 75W-85, API GL -4 is a
premium high performance, synthetic gear lubricant for synchronized
manual transmissions. The all new "clean slate" approach
enables Syntorq LT to provide consistent performance and durability
under the most severe operating conditions due to its unique polymer
free formula. It has been designed primarily as a problem solving gear
lubricant for manual transmissions to provide reduced gearshift effort
at low temperatures. Syntorq LT is available through General Motors
(Part #12346190) and Chrysler (Part #4637579) dealerships. Please
contact your local dealership."
In some conversions, a Dodge input shaft is used in a GM trans, or
vice versa. When we supply the trans, it will come with the correct
input shaft in it for the application. If you already have the trans,
and need to change the input shaft, this is easily done from the front
of the unit and Does NOT require major disassembly of the trans. It is
recommended to check main shaft end play after the swap, incorrect
endplay can cause premature trans failure. To check end play, use a
magnetic base dial indicator, zero it in on the rear of the trans main
(output) shaft. use a small pry-bar or screwdriver to move the
mainshaft in and out of the trans, reading play on the dial indicator.
Should be .002-.006
Impact offers NV4500s transmissions with either 6.34 ratio
1st gear or 5.61 ratio first gear. For the first
two years of production of these transmissions in General Motors
vehicles, they were built with an extremely wide ratio 6.32 to one
not as smoothly drivable on the road, the 6.34 ratio unit is in many
cases the ultimate off-road off road manual trans. In vehicle using
dual transfer cases or extreme underdrives, the 5.61 unit is generally
better, as you don't need to squeeze that last little bit of low gear
out of the trans
The 6.34 ratio transmissions are available ONLY with the GM input
shaft, and the early GM NV4500 bolt pattern. They are not interchangeable
with the later GM or Dodge NV4500s. This is important to know as our
bellhousing adapter plates must use the Dodge input shaft (it is
longer). Therefore they MUST use either an early GM factory
bellhousing, or several aftermarket full bellhousings we offer to use
this transmission with AMC and GM engines. Conversions must be
specifically designed for this transmission. We CAN supply them with
GM or Dodge output housings/shaft.
Impact can provide NV4500 transmissions available in GM/Dodge
factory stock configurations, or custom configurations. This
means we can supply an NV4500 with, say a Chevy input
shaft, but with a 23 spline output shaft and the Dodge style tail
housing. Custom configurations in some cases lower the cost and complexity of a
conversion because in some cases one configuration will mate better to
the motor, but the another will mate up the the Tcase better.
Misc Tech Notes
Clutch Linkages: Considerations putting later systems into older
Master cylinder: The easiest master cylinder to bolt in to your
vehicle would be the one the one from YOUR year and model vehicle, it
will fit a stock firewall and clutch pedal. There are potential
problems here, however: The master cylinder must have a compatible
fluid displacement with the slave, otherwise proper clutch travel may
not be achieved. Also, late model parts have OEM specific fittings
that the aftermarket custom hose shops do not seem to have, so custom
hoses often involve cutting up two stock hoses and having them
coupled. And some late model hoses are only available from the dealer,
and as a PART of a COMPLETE assembly they will not break up. (Such as
a master cyl-hose combo, where they will not sell you only the hose).
In these cases we have found it easier to USE the OEM matched
master-hose-slave combo, and modify the brackets to mount the master
cyl to the firewall, and the modify the linkage rod as needed to the
pedal to get the correct travel for the slave cyl. This way you know
the hose fittings match up, and the master and slave are hydraulically
matched. Our packages are generally engineered in the manner that is
the closest to trouble free, although you are free to choose whatever
method you prefer for your project.