The New Process NP-271 and NP-273 are a series of heavy duty, chain driven transfer cases commonly found in Dodge and Ford pickup trucks. The NP-271 and NP-273 are nearly identical with mostly interchangeable parts; the NP-271 is a manual shift transfer case, while the NP-273 is an electric shift variant. The Dodge and Ford cases are very similar but use different input shafts to mate to their respective transmissions.
The New Process and New Venture Gear names are often used interchangeably. New Venture Gear was a joint venture between GM's Muncie transmission division and Chrysler's New Process Gear in the early 1990's. Although products were often identified as New Venture, transfer cases produced at the New Process plant in Syracuse, New York often retained the New Process logo and name on product tags. The New Process and New Venture names are therefore used synonymously, thus the NP-271 is identical to a NV-271 and the NP-273 is the same as a NV-273.
Ford began using the NP-271 and NP-273 transfer cases in the 1999 Super Duty. Four wheel drive F-250, F-350, F-450, and F-550 pickup and chassis cab trucks through the 2010 model year were equipped with one of these two transfer cases. Dodge and later Ram trucks used the pair of transfer cases beginning in 2003, but would adopt a BorgWarner unit following the 2012 model year. These transfer cases are found in four wheel drive Ram 2500, 3500, 4500, and 5500 pickup and chassis cab trucks.
These transfer cases have a relatively large, 1-1/2 inch wide chain. An oil pump mounted at the rear of the case and driven off the output shaft is used to keep the bearings lubricated. At approximately 120 lbs, the case is light relative to its robustness. A 6 pinion planetary gearset provides a 2.72 to 1 gear reduction in low range.
Identification
All New Venture/New Process transfer cases have an identification tag attached to the rear housing.
Nomenclature
New Venture/New Process transfer cases follow a distinct name convention. The preceding "NP" or "NV" indicates New Process Gear and New Venture Gear, respectively. The first number in the model name indicates the number of speeds (ranges). The following number designates the relative strength on a scale of 1 to 7 and the last number describes one or more attributes wherein:
- 1 = part time four wheel drive
- 2 = full time four wheel drive
- 3 = electronic shift
- 5 = Torsen-type differential transfer case
- 6 = computer controlled, multi-plate wet clutch transfer case
- 7 = GeroDisc transfer case
- 9 = viscous coupling transfer case
Note that the numbers 4 and 8 are not used. From this information, the NV-271 and NV-273 transfer case models break down to:
- NV = New Venture Gear (NP = New Process Gear)
- 2 = two speed transfer case (low and high ranges)
- 7 = highest strength designation
- 1 or 3 = part time four wheel drive or electric shift
- D, F
- D = Dodge
- F = Ford
Transfer Case Specs
| Manufacturer | New Venture Gear | |
|---|---|---|
| Designations | 271 | NV-271, NP-271, NV-271F, NP-271F, NV-271D, NP-271D, NVG-271, 271-D, 271-F |
| 273 | NV-273, NP-273, NV-273F, NP-273F, NV-273D, NP-273D, NVG-273, 273-D, 273-F | |
| Production Plant | New Process Plant, Syracuse, New York | |
| Applications | 2003 - 2010 Dodge Ram 2500, 3500, 4500, 5500 2011 - 2012 Ram Trucks Ram 2500, 3500, 4500, 5500 1999 - 2010 Ford F-250, F-350, F-450, F-550 Super Duty 1999 - 2005 Ford Excursion |
|
| Max GVWR | 17,500 lbs | |
| Type | Part time, chain drive | |
| Drop | Driver side | |
| Shift Type | 271 | Manual shifter |
| 273 | Electric motor | |
| Case Material | Cast aluminum | |
| High Range Ratio | 1.00:1 | |
| Low Range Ratio | 2.72:1 | |
| Input Splines | Dodge/Ram | 23 spline with automatic transmission, 29 spline with manual transmission |
| Ford | 24 spline with manual transmission, 31 or 34 with automatic transmission | |
| Weight | Approximately 120 lbs | |
| Lubrication | Internal oil pump driven off of the output shaft | |
| Fluid Spec | Dodge/Ram | MOPAR ATF+4 automatic transmission fluid |
| Ford | Motorcraft MERCON LV automatic transmission fluid [1] | |
| Fluid Capacity | 2.0 quarts (4 pints) [2] | |
| Service Intervals | Dodge/Ram | 60,000 miles/48 months under normal driving conditions 30,000 miles/24 months under "severe" service conditions [3] |
| Ford | 150,000 miles under normal driving conditions 60,000 miles under "severe" service conditions [3] |
|
[1] - Supersedes all previous specifications; see Ford transfer case fluid timeline
[2] - Always fill transfer case to bottom of fill plug opening
[3] - Includes frequent use of the four wheel drive system, operating in extremely hot temperatures; drain and replace transfer case fluid anytime it is submerged, water intrusion probable
Lubricants & Maintenance
Chrysler calls for MOPAR ATF+4 automatic transmission fluid in the Dodge/Ram variants of the NV-271 and NV-273 transfer cases. The Ford versions originally required MERCON automatic transmission fluid, but that has since been superseded and the modern specification is MERCON LV automatic transmission fluid. Ford MERCON V is never an acceptable ATF to use in a transfer case.
All NV-271/273 transfer cases have a 2.0 quart capacity regardless of application. Although Ford has less stringent service guidelines for these transfer cases, I strongly urge service at 60,000 mile intervals in all applications. If the four wheel drive system is used frequently or the vehicle is exposed to extremely hot temperatures (high loads from towing, long trips in high ambient temperatures), replacing the fluid every 30,000 miles is advised.
Fluid should also be checked periodically - these units have a small fluid capacity and thus even a small loss of fluid could negatively impact lubrication and cooling within the gearbox. Verifying the fluid level is as simple as removing the fill plug with the vehicle parked on a flat, level surface. The fluid level should reach the bottom of the fill plug opening.
Editor, Diesel Hub