NP231

The NP231 is a part-time two-speed transfer case used across Jeep, Chrysler and GM light trucks. Remanufactured NP231 transfer cases in this category are exchange units and are listed by vehicle, input spline and output configuration.

What fits what

Jeep coverage runs 1987 through 2007: Cherokee and Comanche 1987-1990, Cherokee and Wrangler 1987-1995, Grand Cherokee 1993-1995, Wrangler TJ 1997-2006, and Liberty 2002-2007. Chrysler and Dodge coverage runs 1988 through 2001: Dakota 1988-2000, Durango 2000, and RAM 1500 1994-2001 in both manual and automatic transmission versions. GM coverage is S10 and S15 from 1992 through 1998, including extended cab.

How to identify yours

The tag number on the case is the definitive answer, and it is published on these listings – Chrysler and Jeep tags read like 52097522, 52098480, 52099310, 52105407AD, 53005382 or 53008207. After that, match the input: 23 spline is standard on most, but the exposed length differs, 0.84 inch on some and 1.55 inch on others. The rear output is either 27 spline or 32 spline, slip yoke style, and some 27 spline units use an exposed spline shaft with a rubber boot. The front output yoke is bolt-on, cup style or flat circular, and some units use a fixed front yoke. Check for a 1.75-inch speedo hole or none at all, a one-piece or two-piece tail housing, and the shift indicator switch type (two-pin, wire or vacuum) and its position above the shift shaft.

Read the notes on the Slip Yoke Eliminator units. Those are built with an SYE kit and a 1310 CV-style rear yoke, they are listed as not for stock applications, and they will require an aftermarket rear driveshaft that is not included.

Core charge and warranty

These are exchange units – a refundable core charge may apply and your old case goes back as the core. Each unit carries a 6-month limited warranty as standard. A 7-year / 1,000,000-mile extended warranty and a core fee waiver are available on request for qualifying remanufactured units, arranged at the time of purchase and not applied automatically. Call 216-250-6666 with your tag number before ordering.