NP241OR- ROCTRAC & NP241J
In 2007, Jeep introduced the NP241J 2.72:1 low range as well as continued to use the Rubicon NP241OR RocTrac Transfer Case 4.0:1 low range.
The design of the Jeep NP241 is based off of the robust NP241 transfer case commonly found in full size Dodge/GM trucks. Much like the truck NP241, the Jeep 241 comes factory with a 32 splined rear output shaft equipped with a fixed yoke. The front driveshaft is located on the driver's side of the vehicle and is likewise offered with a 32 spline output.
As with most chain driven transfer cases, the 241 operates in four shift modes. The transfer case shifts in the following patterns: 2wd high, 4wd high, neutral, and 4WD low. The case can be identified by the silver and red metal identification tag that is riveted to the rear section of the transfer case. The RocTrac measures 15-1/4” in overall length and weighs in at about 92 lbs. The front of the transfer case uses the standard Jeep round circular 6 bolt pattern as found on the NP231.
Replacement Knobs for the JK are part numbers 715597 or 715598
Prior to 2012, all NP241's received a short 23 spline input shaft and were mated to either the 42RLE, NV3550 or the NSG370 transmissions. In 2012, Jeep retired the 42RLE and replaced it with the A580 five-speed automatic. The 241's used behind the A580 utilized a special 26 spline male shaft for the input.
Advance Adapters offers numerous transmission-to-transfer case adapters for the 23 spline version of the NP241; however, we do not offer any adapters for the 26 spline version of the 241.
The JK model of the 241's do not have a VSS provision since Jeep relocated the speedometer to the axle. It also should be noted that the shifter linkage was removed from the body and a cable shifter was utilized. We have seen numerous failures on this cable system mostly as a result of plastic heim joints being used. We offer an upgraded cable kit under 715596. This new heavy duty design was created for the off roader who is consistently shifting the transfer case in and out of its various ranges. The improved cable and mounting system offers both a durable and dependable system, replacing the easily worn out factory JK transfer case shifting system.
Over the years we have seen good success of NP241's even behind V8 power. Although the NP241 is significantly better than a NP231, it is not impervious to failure. It's still a chain driven transfer case and does not offer the twin stick features like an Atlas. To learn about the Atlas into a Jeep JK, click here for ATLAS-JK or to order a specific Atlas for the JK click here for Atlas Build
The other option for the JK’s with the 241 and the 42RLE automatic transmission is the addition of a Rubi-Crawler. This is a reduction box that provides you with a 2.72:1 low ratio in 2WD and 4WD in addition to an ultra-low range of 7.34 :1 or 10.88:1. The Rubi-Crawler can be installed into a Jeep within a day without any driveshaft modifications.
For more information click here for RUBI-CRAWLER