The NP229 transfer case was manufactured by the New Process Gear Division of Chrysler, also known as the New Venture Gear Company. The unit was used by Jeep from 1982 through 1991 as their "Selec-Trac" option. NP229 Basics The NP229 is a part-time unit with an aluminum case. It is chain-driven and features an offset output. As a part-time 4WD case, it should only be used in 4WD mode when
