NP241

The NP241 is a heavy-duty two-speed transfer case built for three-quarter-ton and one-ton trucks and, in its Rock-Trac form, for the Jeep Wrangler. Remanufactured NP241 transfer cases here are exchange units, split by input spline and rear output.

What fits what

GM coverage runs 1988 through 2002: S10 and Suburban 1988-1989, Blazer and Suburban 1989-1991, K-series 1988-1994 and 1995-2002, 1500 with the 4L60E in 1993-1994, and K-series, Suburban and Yukon 1994-1999. Dodge and RAM coverage runs 1988 through 2002: W150 and W250 1988-1993, 2500 and 3500 in 1997, and 2500 and 3500 1998-2002. Jeep coverage is the Wrangler JK, 2007-2014, including the automatic transmission version.

How to identify yours

Front input spline count is the first split – 23, 27, 29 and 32 spline units are all listed here, and they are not interchangeable. The rear output is slip yoke style in 31 or 32 spline, and the 31 spline units are called out with a 1.608-inch outside diameter on the output shaft. The front output yoke is either flat circular or a 4-inch bell style. Then check whether the case has a PTO opening or PTO covers, whether there is a speedo hole, and whether the indicator switch is two-prong or three-prong (some rear slip output units are described as two-wire or three-wire). Jeep JK units are listed with and without the Rock-Trac option and carry a 2.72:1 low range. GM tag numbers on these cases include 15603967, 15604177, 15611485, 15622870, 15659718, 15675348, 15696731, 15733769, 15961729, 15965649, 15965651, 15982717 and 15982720.

Core charge and warranty

Exchange units: a refundable core charge may apply and your old transfer case is the core. Every unit carries a 6-month limited warranty as standard. For qualifying remanufactured units a 7-year / 1,000,000-mile extended warranty and a core fee waiver are available on request and must be arranged at the time of purchase – they are not automatic. Call 440-374-1039 with your tag number and spline count.