The New Venture Gear NV4500 at a glance
The New Venture Gear 4500, a 5-speed manual transmission manufactured by New Venture Gear, was used in General Motors and Chrysler products from 1992-2007. The NV4500 gained popularity as a 5-speed manual conversion and upgrade transmission in light trucks and SUVs from Dodge, Jeep, General Motors, Ford and Toyota.
When it was released, many hailed its strengths, particularly the high overdrive, though some have criticized its low gear as not being low enough for off-road use. The transmission is too long to retrofit to many Jeeps.
The NV4500 was first used by Dodge in 1992. It had a one-inch, 19-spline input shaft and an interlock mechanism built into the 1-2 synchronizer assembly, to prevent downshifts to first and second gears at higher speeds. The current gears on the Dodge and GM versions of the NV4500 are fully synchronized, including reverse, with synchronizer rings made of a carbon fiber composite. The NV4500; dual cone synchronizers are used for first and second gear.
There were many changes made during the production of the NV4500; two main variations were the NV4500LD, which was used with Dodge V8s and GM gas and diesel engines, and the NV4500HD, which was used in Dodge trucks powered by the Cummins diesel and V10 gas engines. The HD (Heavy Duty) version was unveiled in 1994, and had an increased input torque rating of 460 lb-ft, thanks partly to a 1 1/4” ten-spline input shaft.
Grissom wrote that the NV4500 manual transmission is prone to popping out of (or not getting into) fifth gear because the nut holding the gear on loosens up; he said he’d never seen the problem in other transmissions including the 3500. The problem may get worse, affecting other gears, later.
Leaks can be caused by overfills, as well as by seal issues. If a leak shows up at the rear of the extension or adapter housing, it is likely from the housing seals; if it shows up at the front, it could be the front bearing retainer or the retainer seal. Other leaks, where components meet, could be due to problems with the sealer or incorrect bolt tightening. Leaks can cause extensive damage if not fixed, and can destroy the clutch.
Normal noises include an audible whine at extreme speeds; other noises are usually due to lubricant issues. Hard shifting, noise, wear, and internal binding are usually caused by lubricant issues — dirty gear oil, low levels, or the wrong lubricant. Hard shifting can also be caused by clutch maladjustments or damaged clutch components.
Worn synchro rings can result in gear clash when going into forward gears (though they can stick somewhat in new or recently rebuilt transmissions, leading to hard or noisy shifting, which gets better as the rings wear in).
Synthetic gear oil is required, partly due to the carbon composite gear synchronizers. New Venture Gear recommended 75W-90 Castrol Syntorque Synthetic (not the same as Castrol Syntech), Mopar P/N 4974459 (Material Specification 9070) 75W85 manual transmission lubricant, and GM Synthetic Manual Transmission Fluid (P/N 12346190; in Canada 10953477). Alternate lubricants could ruin the synchronizers and void the warranty. Even oil that directly states compatibility with the Mopar and GM lubricants above could still void an OEM or rebuilders' warranty.
Vince Spinelli wrote: “The spec is for GL-4 lubricant, NOT the commonly available GL-5 that we've all been using in our front and rear axles these past few years. Use any high quality 75W85 GL-4 Synthetic Gear Oil. Items such as Mobil 1 Synthetic, Castrol Syntorq, or Valvoline Synpower will all do the job nicely. ... GL-4 (Gear Lubricant-4) contains about half the additives of GL-5. Higher concentration of Extreme Pressure additives in GL-5 gear oils may cause the softer metals, such as copper, brass and bronze ... to suffer premature wear / failure.” (See his gear oil article)
NV4500 Specifications and gear ratios
|Gear||Ratio||Notes and Specifications|
Dry weight: 195 lbs.
|Reverse||5.61 (1994-97) 39T|
|Reverse||5.04 (1998-up) 35T|
Important: these are believed to be the applications but some of these vehicles may have variants, and may not be interchangeable. A wrecking yard or dealer should have an interchange guide.
General motors used the NV4500 as RPO MT8 and MW3 in 8500 and GVWR light trucks from 1992-2006. 1992-2007 GM units used the corporate V8 bellhousing to engine bolt pattering. They had:
- Input shaft measuring 6 5/8" in length, 1.125" in diamete with 10 splines and a .590" diameter pilot
- 2WD use a fixed yoke output; 4WD use a 32 spline output
- 1992-94 RPO MT8 units had a different bellhousing bolt pattern than GM 4-speeds, as well as right hand mounted hydraulic slave cylinder with fork-mounted throwout bearing and unsynchronized reverse
1995-2007 RPO MW3 units had the Dodge transmission to bellhousing bolt pattern; a concentric internal hydraulic clutch slave cylinder with integrated throwout bearing; and synchronized reverse
All Dodge NV4500 units had:
- Dodge NV4500 transmission to bellhousing bolt pattern (shared with 1995-2005 GM light trucks)
- Dodge specific input shaft 7.5" long with a .725" diameter pilot shaft diameter and spline count varies
- Concentric internal hydraulic clutch slave cylinder with integrated throwout bearing
- 1992-1997 2WD gear drive speedometer in tailhousing. (Some 1998 may have gear drive)
- From 1998: 2WD had no speedometer gear (VSS in axle)
Standard duty 1992-2005 order code DDP:
- All years have Dodge small block bellhousing to engine bolt pattern
- 1992 only: 1" diameter 19 spline input shaft
- 1993-forward: 1.125" diameter 10 spline input shaft
- 1992-forward: 2WD 30 spline output
- 1992-2000: 4WD 23 spline output
- 2001-forward: 4WD 29 spline output
Heavy Duty 1994-2005 order code DDX:
- All years used with 5.9 Cummins Turbo Diesel and 8.0 V10
- All years 5.9 Cummins Turbo Diesel and 8.0 V10 bellhousing to engine bolt pattern
- All years 1.25" diameter 10 spline input shaft
- All years 2WD 31 spline output
- All years 4WD 29 spline output