Why Transfer Case Identification Matters
When you call us about a transfer case rebuild or replacement parts, one of the first things we need is the assembly number from the build tag. Year and model get us close, but "close" means wrong parts. The same truck can have a light-duty or heavy-duty transfer case depending on factory options, and the internal components — input shafts, bearings, planetary gears — changed multiple times within a model run without changing the external appearance.
If you're rebuilding a transfer case or ordering parts for one, find the tag first.
The Build Tag — Where to Find It
New Process (NPG) and New Venture (NVG) transfer cases have a round metal tag attached to the back of the rear case half. Stamped on the tag are:
- Model number (e.g., NV271D, NP241DHD, MP271)
- Assembly number — an 8-digit number plus two letters
- Build date
- Low range ratio (usually 2.72:1)
The assembly number is the critical piece. It tells us exactly what internal components your transfer case was built with — input shaft type, bearing width, planetary gear tooth profile, and more.
Tag Variations by Manufacturer
New Process Gear (Syracuse, NY): Red and silver tag with the NPG logo and "New Process Gear Syracuse, New York." Numbers are die-stamped.
Early Magna (Indiana): Same red and silver tag style, but "Syracuse N.Y." is usually absent. Numbers are typically dot-peened instead of die-stamped.
Current Magna Powertrain (Muncie, IN): Tag reads "Magna Powertrain" (top) and "Muncie IN" (bottom) in red, with dot-peened numbers.
Magna Mexico: Unpainted tag, just stamped with the ID numbers — no other markings.
The Identification Decal
SStarting in the mid-1990s, most transfer cases also have a factory-applied decal, usually on top of the front case or on the bottom edge of the rear housing. The decal has a barcode, serial number, Dodge assembly part number, and New Process assembly number..
These decals are designed to last, but by the time a transfer case needs service, they're usually gone or illegible. If the round tag is missing, look for the decal.
NNV4500 Transmission Build Tagss
While not a transfer case, the NV4500 5-speed manual transmission is one of the most common components we get calls about, and identification follows the same pattern. Two tags were installed at the factory:
- Metal ID tag — secured by two of the left PTO cover bolts
- ID decal — on the top cover
Per the factory service manual: "The tag provides the transmission model number, build date and part number. Be sure to reinstall the I.D. tag if removed during service. The information on the tag is essential to correct parts ordering." That last line is the factory telling you not to lose the tag — and yet most of them are missing by the time someone calls us.
The assembly number is critical because NV4500 internals changed multiple times. A 1997 NV4500HD for a Dodge diesel looks almost identical externally to a 1996, but internally the gears and gear ratios are different. If the transmission has been rebuilt or swapped, the original tags may be gone — and that means detective work before ordering parts.
What the Factory Service Manual Says
From the 2000 Dodge Ram factory service manual (we've OCR'd and digitized all of ours):
"An identification tag is attached to the rear case of every transfer case. The tag provides the transfer case model number, assembly number, serial number, and low range ratio. The transfer case serial number also represents the date of build."
That's the factory's own instruction: find the tag, read the numbers, order parts from those numbers. We follow the same process — the assembly number is what we use to look up exactly what's inside your transfer case.
1994–2002 Dodge Ram NP241D Transfer Case — DLD vs DHD
Dodge used New Process NP241DLD and NP241DHD transfer cases in 1994–2002 Ram heavy-duty 4x4 trucks. Both are 2-speed, neutral-capable, aluminum case, left-drop, chain drive, manual shift units with a 2.72:1 low range. They look the same on the outside.
- NP241DLD (Dodge Light Duty): Base transfer case for Ram 2500 and 1994–1997 Ram 3500
- NP241DHD (Dodge Heavy Duty): Optional on 1994–1997 Ram 3500 and 1997–2002 Ram 2500; standard on 1998–2002 Ram 3500
The build tag will tell you which you have. If the tag is missing, the assembly number may also be stamped on the rear case. The key internal differences are in the input shaft, planetary gear set, and mainshaft — the DHD uses heavier components rated for higher torque.
Wide vs. Narrow Tooth Planetary Gears
Early production 1994–1995 (and possibly some very early 1996) Ram 2500 and 3500 NP241D transfer cases have a wide-cut planetary gear set. Later production uses narrow-cut teeth. The gear diameters differ by 0.020"–0.025" between the two types. While the gears should ideally not be mixed, narrow-tooth input shafts have been successfully used in wide-tooth cases when wide-tooth replacements are unavailable — many thousands have been installed this way.
Input Shaft and Bearing Details
Input Bearing Width
Most NP231, NP233, NP241, and NP242 transfer cases use input bearings with the same inside and outside diameters, but two different widths were used:
- Narrow: 16mm (5/8") wide, single row, 14 balls
- Wide: 15/16" wide, double row, 24 balls
During the 1990s, New Process was building transfer cases that were externally interchangeable but used different input shafts and bearings internally. A narrow bearing won't work on an input shaft made for the wide bearing, and vice versa — but the combined shaft-and-bearing assemblies are fully interchangeable for similar applications. When you're replacing an input shaft for a conversion, you can change the bearing width by changing the shaft.
Clutch Tooth Profiles
The sliding range sleeve in most NPG/NVG 2-speed chain drive transfer cases engages clutch teeth on the back of the input shaft (high range) or the planetary carrier (low range). Two tooth profiles exist:
- Single-cut (1-way): Beveled in one direction. Most common on vehicles without locking hubs or central axle disconnect.
- Double-cut (2-way): Beveled equally both ways. Used on almost all transfer cases up through the mid-1990s, and after that primarily on applications with front axle disconnect.
For stock applications, both types work fine. When replacing a worn input shaft or range sleeve, match the original tooth profile unless you have a specific reason to change it.
Still Not Sure?
If the build tag and decal are both gone:
- Check for any stampings on the rear case half
- Note the number of bolts on the rear case and any external features (shift lever location, speedometer drive, front output type)
- Know your truck's year, model, engine, and transmission — that narrows the options significantly
- Take photos of the case from multiple angles
Send us the photos and info. We identify these every day. Call (866) 251-6762 or email sales@torqueking.com.
Tech Pages
Detailed transfer case identification pages organized by make:
- Chevy & GMC Transfer Case ID
- Dodge & Ram 4x4 Truck Parts
- Ford Transfer Case ID
- Jeep Transfer Case ID
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