Transfer Case Identification
Transfer Case Specification Chart
Which transfer case is in my Jeep?
Early CJ models (CJ-3B, CJ5, CJ6) run the Dana Spicer 18 until 1971, the CJs of the 1970s the Dana 20, and from 1980 the Dana 300. Wrangler YJ and TJ and Cherokee XJ use the NP231 from 1988 to 1997, the Grand Cherokee ZJ the NP242 or NP249, the WJ/WG the NV242 or NV247. Years, vehicles and ratios of all types are listed in the chart below.
What does NP231 or NV242 mean?
NP stands for New Process Gear, NV for New Venture Gear. The first digit gives the number of speeds – 2 means high and low range – and the last digit the drive type: 1 is part-time 4WD, 2 is full-time 4WD. The full breakdown is in the nomenclature chart below.
| Year | Vehicle | Model | Ratio |
|---|---|---|---|
| 1940-1971 | CJ-3B, CJ5, CJ6 | Dana Spicer 18 | 2.46:1 |
| 1973-1979 | CJ7, SJ, Wagoneer | QuadraTrac BW1339 | 2.57:1 |
| 1972-1979 | CJ5, CJ6, CJ7 | Dana 20 | 2.03:1 |
| 1980-1986 | CJ5, CJ7, CJ8 | Dana 300 | 2.60:1 |
| 1984-1987 | XJ, YJ | NP207 | 2.60:1 |
| 1980-1990 | SJ, Wagoneer | NP208 | 2.61:1 |
| 1978-1982 | SJ, Wagoneer | NP219 | |
| 1981-1991 | XJ, MJ, SJ, Wagoneer | NP228/ NP229 | 2.61:1 |
| 1988-1997 | YJ, MJ, XJ, TJ | NP231 / NV231 | 2.72:1 |
| 1987-1997 | XJ, MJ | NP242 | 2.72:1 |
| 1993-1998 | ZJ, ZG | NP242 / NP249 | 2.72:1 |
| 1999-2004 | WJ, WG | NV247 | 2.72:1 |
| 1999-2004 | WJ, WG | NV242 | 2.72:1 |
Nomenclature
| Manufacturer | Number of Speeds/Gears | Strength | Type |
|---|---|---|---|
| NP = New Process Gear | 1 = One speed (high range) | 1 (low) to 7 (high) | 1 = Part-time 4WD |
| NV = New Venture Gear | 2 = Two speed (high and low range) | 2 = Full-time 4WD | |
| 3 = Electronic shift | |||
| 4 = Not currently used | |||
| 5 = Torsen-type differential | |||
| 6 = Computer controlled multi-plate wet clutch | |||
| 7 = GeroDisc | |||
| 8 = Not currently used | |||
| 9 = Viscous coupling |