NV4500 Transmission Overview
The NV4500 transmission is a heavy duty 5-speed that saw use in a number of Chrysler and GM trucks from 1992 – 2007. The NV designation stands for the New Venture Gear Corporation, which came about from a merger of General Motors’ Muncie transmission division, and Chrysler’s transmission division, which was called the New Process Corporation. After joining forces, this new joint transmission company created a number of gearboxes that were shared between the two automotive giants. The NV4500 was one of their first transmissions, and it was good enough to remain in production for almost 20 years. The NV4500 transmission is a heavy duty 5-speed manual gearbox that features a granny low first gear, with a fuel saving overdriven 5th gear. It has a constant mesh helical gear arrangement, and all forward gears are fully synchronized. Reverse gear was not initially synchronized, however later versions are. The transmission case is made from cast-iron, with an aluminum top cover and dual PTO ports. There were a number of different versions and configurations available, and the most common are the NV4500LD transmission and the NV4500HD transmission.
What Transmission Do I Have?
GM NV4500 Transmission
The 1992-1994 GM NV4500 transmission had an extremely low first gear ratio of 6.34, a 3.44 2nd gear, a 1.71 3rd gear and a 4.685” front bolt pattern. In 1995, the GM NV4500 received the same 5.61 first gear ratio and 6.043” bolt pattern that was found in the Dodge NV4500, along with a 3.04 2nd gear and a 1.67 3rd gear. A fully synchronized reverse gear was also added, and the front bearing retainer grew from 5.125” to 5.6” in diameter. Noticeable differences on the GM NV4500 4WD transmission include a 1 1/8” x 6 5/8” 10 spline input shaft (0.590” pilot tip), and a 32 spline output shaft, with an 8 1/8” tailhousing.
GM NV4500 Transmission Gear Ratios
1st = 6.34 | 5.61
2nd = 3.44 | 3.04
3rd = 1.71 | 1.67
4th = 1.00
5th = 0.73 | 0.75
R = 6.34 | 5.61 | 5.04 (after 1998)
Dodge NV4500 Transmission
Used in Dodge trucks from 1992 – 1997, the Dodge NV4500 had a higher gear ratio than the GM variant. It shared the same bellhousing bolt pattern as the 1995 – 2005 GM version. But all forward and reverse gears were fully synchronized with carbon fiber composite synchronizer rings, and dual cone synchronizers for first and second gear. The NV4500 1-2 synchronizer assembly also had an integrated interlock mechanism that would prevent accidental 2-1 down shifts at higher speeds. There was a concentric internal hydraulic slave cylinder with an integrated throwout bearing. And 1992 versions got a 19 spline, 1” diameter input shaft. 1993 and up models had a 1.25” diameter input shaft with 10 splines. 2WD versions got a 30 spline output shaft, 4WD got a 23 spline output shaft, but that was changed to a 29 spline shaft after 2001.
Dodge NV4500 Transmission Gear Ratios
1st = 5.61
2nd = 3.04
3rd = 1.67
4th = 1.00
5th = 0.75
R = 5.61 | 5.04 (after 1998)
NV4500 Transmission Gear Ratios
1st = 6.34 | 5.61
2nd = 3.44 | 3.04
3rd = 1.71 | 1.67
4th = 1.00
5th = 0.73 | 0.75
R = 6.34 | 5.61 | 5.04 (after 1998)
What Transmission Do I Have?
Common NV4500 Transmission Problems
- Worn synchronizer rings
- Dirty transmission fluid or overfilling the transmission fluid can lead to leaks, hard shifting and binding
- Popping out of or not going into fifth gear can be attributed to a loosened nut on the gear housing
