The Novak Guide to the

New Process 208, 219, 228 & 229 Transfer Cases

as found in

FSJ & XJ Jeeps, 1980-1991

fsj_np208_219_228_229In 1980, the full-size Jeeps made a major shift in Jeeps 39 year history to a driver's side front differential and the widespread use of chain-driven transfer cases. These transfer cases include the New Process 208, 219, 228 and 229 models.

Features

Featuring chain-driven, planetary reduction in an aluminum case, the NP 2xx have a 2.61-to-1 low range and direct in high.

The NP208 was the simplest of these transfer cases. It featured the classic 2wd direct drive in High range and locked four-wheel-drive operation in both High and Low ranges. The NP208 was provided in the J Series from 1980-1987 and big Cherokee Jeeps from 1980-1983. The Jeep NP208 used a different case, bolt pattern and some different internal parts than the GM / Chevrolet and the Ford 208 versions.

The NP219 was a full-time 4wd transfer case. This transfer case was more complex than the 208 in that it used a viscous clutch. The NP219 was used for two years in Jeeps and then replaced by the 228/229 in 1982.

A New Process ID TagThe NP228 had a direct-drive 2wd mode. It used an internal, open differential for four-wheel-drive mode and high range and featured a fully locked mode in four-wheel-drive, low range. It featured vacuum actuation for mode operation and a conventional shifter linkage for range operation. This transfer case was used in the XJ Cherokees as the optional in lieu of the NP207.

The NP229 was similar to the NP228, but it featured an internal viscous coupling for full-time operation. This transfer case was offered in the FSJ Grand Wagoneer.

Identification

The NP transfer cases are easily identified by the numbering in its red and silver tag on the back. The model number and gear ratio will be listed.

Transmission Compatibility & Adaptability

The Jeep FSJ NP2xx transfer cases are found behind these factory transmissions:

Manuals

Automatics

Adaptation to better transmissions is often less costly than rebuilding the factory Jeep transmissions and provides serious performance and strength upgrades. The 2xx adapts very well to several popular transmissions, including:

 

Manuals

Adapting the 2xx to the SM-420 transmission Adapting the 2xx to the SM-465 transmission Adapting the 2xx to the T-18 transmission Adapting the 2xx to the NP-435 transmission
SM420 SM465 T18 NP435


Automatics

Adapting the 2xx to the TH-350 transmission Adapting the 2xx to the TH-400 transmission Adapting the 2xx to the 700R-4 transmission Adapting the 2xx to the 4L60-E transmission
TH350 TH400 TH700R4 / Early 4L60-E Later 4L60-E

 

Rebuilding the 2xx

The 2xx transfer cases are not difficult to rebuild and all consumable rebuild components are available for them, in addition to a majority of hard parts. Please contact us directly for these kits and components.

Input Gears and Compatibility

The NP2xx transfer cases in these Jeeps featured 23 splines, predominately, with the exception of those versions that were found behind the T18 transmission in the J Trucks, which had 31 splines.

Strength

The NP series transfer cases were quite tough and generally refined. New Process was smart to learn from previous chain-driven transfer case designs and incorporated what they knew into this 1/4+ Ton rated series of transfer cases.

Speedometer Gears

NP2xx speedometer gears are interchangeable to correct for tire size and axle ratio changes. See this page to learn more about this.