General Information: In 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. This 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 creeper gear four-speeds, plus 27-percent overdrive. The cast iron case is combined with massive gearsets in an almost compact 200lb package. As far as driveability is concerned, this unit surpasses the rest with smooth, short action and very distinct shift gates. It has become an extremely popular manual-trans swap and kits are available for Jeep CJ's, Wranglers and Cherokees; Toyota Land Cruisers; and 66'-77' Broncos.

Commonly referred to as simply NV4500, the transmission is identified by Dodge Truck as NVG4500, while Chevrolet and GMC designate it as the MT8 and MW3. The manufacturers' code names for the two transmissions are different and so are some of the internals, yet both gearboxes are made at the same New Venture Gear assembly plant. General Motors applications include it as an option in 3/4 and 1-ton fullsize trucks with a GVWR of more than 8500 pounds. GM also built about 20,000 (rare) 2WD, 1/2 Ton trucks with a 4.3 V-6, that used an NV4500 to increase their towing capacity. Dodge versions are used in 3/4 and 1-ton trucks, mostly with Cummins diesels and V10's.

Gear Ratios:
The Dodge NV4500 and GM NV4500 currently share the same gear ratios. Early GM units (pre 96') 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 more difficult to obtain. Beginning in 95', all GM units were built with the same gear ratios as the Dodge unit. The current GM and Dodge NV4500's are sold new with zero mileage and carries a set of gear ratios which are much more streetable than the early GM model.

Design:
The NV4500 cannot be compared to older 4 speed boxes when it comes to engineered performance. We constantly receive questions regarding the NV4500 in comparison to an older NP435 or SM465. Due to large gears and bearings and a thick cast iron case, the old 4 speed boxes have a long, well deserved history of being super durable. In many cases, the NV4500 features larger gears, better bearings, and heavier duty output shafts. The shifting characteristics of the fully synchronized Dodge NV4500 (even reverse) are excellent. Short, crisp shifts make the NV4500 a luxury to operate compared to the long throw, clunky shifting of earlier 4 speed boxes. The following are a few specifications taken from NVG data.

The bellhousing bolt patterns of all NV4500's are different than any older GM 4 speed bellhousing. This means you cannot bolt a NV4500 directly to an older GM bellhousing. In the early years of the NV4500, the GM and Dodge units did not share a common bolt pattern on the front of the case. In 95' and newer models, the front case bolt patterns of all NV4500's were retooled to the Dodge configuration. Input bearing retainers and input gear sizes/lengths remain different among the Dodge and GM variety as do tailhousings and output shaft spline specifications.

The NV4500 is a top loader style transmission. The lever located in the top shift cover operates the shift forks and rails directly. The shift forks and rails are all located within the aluminum top cover which is bolted and dowel pinned to the top of the gear case. The control handle that protrudes out of the top of the transmission cover has been changed three different times. The handle that fits onto the top of the transmission can be purchased from us directly or from your local GM or Dodge dealership. Tapered roller bearings support the input shaft, main shaft, and counter shaft in the gear case. Drive gear thrust reaction is controlled by a needle-type thrust bearing which is located between the input shaft and main shaft. The main shaft gears are all supported on cage-type roller bearings. This particular design provides excellent lubrication and a minimal amount of gear noise.

Lubrication:
The synchronizer design of the NV4500 demands a specific 90W synthetic oil. The leading cause of GM and Dodge warranty claims on NV4500's are failures due to improper oil choice. The factory service manual for the NV4500 indicates the first oil fill is a lifetime factory fill. If you receive a new NV4500 and it is empty it should be filled with the factory specified oil and not changed unless contamination occurs. The easily identifiable look and smell of the OEM synthetic oil is like no other oil. The GM part no. for the correct oil is 12346191. Use of ANY other oil in the NV4500 will lead to failure and also voids any chance of a warranty claim

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