The NSG370 transmission was introduced in 2005 as the first six-speed to ever equip a Jeep. The transmission was direct evidence of Chrysler's then-league with Daimler.
NSG is an acronym for the German "Neues Schaltgetriebe"; literally meaning "new switching transmission" or "new manual shifting transmission".
The 370 transmission replaced the similar-strength NV3550 and the light-duty NV1500 in the Wrangler and Liberty vehicles. The 370 was installed in other Chrysler and Mercedes products, such as the Crossfire and ML Series.
The NSG370 is a top-shifting, longitudinally-loaded transmission. It features six speeds with a direct drive fifth gear and an overdriven sixth gear. It is fully synchronized in all gears and has helically cut gears for all speeds.
The NSG370 has a cast aluminum case with generous ribbing. It's integral front bellhousing is available in a Jeep 4.0L I6 version and a Mopar 3.7L V6 version. The front bearing retainer has an integral throwout sleeve for a conventional throwout bearing.
Spline count for the input shaft is 10 splines x 1-1/8" diameter. The output shaft for Jeep applications has 23 splines.
NSG370 Specs at a Glance
The NSG370 is quite strong, featuring a 272 ft. lbs. input torque capacity, as claimed by the manufacturer. Output torque limits are between 1100-1300 ft. lbs., making it a good match for the NP231 and NP241OR transfer cases. The construction of the gears and visibly good level of engineering within the transmission would suggest that it should be quite durable.
However, individuals have reported problems with the 2005 model transmission popping out of reverse gear. This was widespread enough to garner the admission of DCx that an update may be needed, which consisted of a reverse gear kit (#05175903AA), itself comprised of a new reverse gear, slider and synchro ring, plus snap rings, an oil seal and countershaft seal plug, incidental to the tear-down required.
The 370 was factory married to the NP231, NP241OR and NP241J transfer cases. It features the common Jeep / Dodge 6-bolt transfer case mounting face for driver's side drop transfer cases. The 23 spline output shaft makes it compatible with the 23 spline version of the above transfer cases.
The 370 is factory compatible with the Jeep / AMC 4.0L I6 engine, when equipped with the right bellhousing. It is also compatible with the 3.8L V6 when equipped with its matching bellhousing.
Chevrolet and GM Gen. III+ Small Block V6 and V8 conversions to the NSG370 are done with excellent success.