NP231 vs NP242 Transfer Case – Which One Is Better?

If your Jeep requires a full-time NP241 or a part-time NP242, you must find answers to several questions about the key differences between each transfer case before purchasing.

For instance, do you know which one is better for you? How does it differ from the others? How will it affect the performance of your vehicle and your driving experience? If you have trouble deciding which option is right for you, I have a solution for you. You will find everything you need to know about the NP231 vs NP242 in this NP231 vs NP242 comparison guide.

NP231 Vs NP242– Detailed Comparison

NP231 and NP242 are two entirely different options since NP242 is a full-time option whereas NP231 is a part-time option. Each transfer case displays a different potential in different driving conditions. Before a comparative discussion of both transfer cases, let’s take a look at them briefly.

What Is NP 242?

There is no doubt that the NP 243 is one of the most versatile transfer cases you will ever buy for your Jeep. With its intuitive design and solid performance, it has proven to be one of the most reliable transfer cases for off-roading vehicles. There are five different driving modes with this transfer case, including full-time, part-time 4WD, 2WD, and 4WD.

The red and silver tag on the rear of the case identifies the NP242 transfer case. This case is compatible with both automatic and manual transmissions and is very adaptable to a wide range of factory transmissions. SM465, T18, and TH400 are some of the most popular transmissions that work with the NP242.

What Is The NP231 Transfer Case?

Dodge Rams, Jeeps, and SUVs have NP231 part-time transfer cases. With its aluminum body and chain drive, the transfer case is a great option for everyday driving conditions. It is a solid transfer case that is a perfect balance between reliability and performance. For large tires and high torque, this isn’t the best option in terms of power. NP231 has been upgraded and modified so that it can be used under a variety of driving conditions. There are front and rear outputs from the driver’s side. 2.83:1 is probably the lowest gear ratio in this range.

What Transfer Case Is Better 231 Or 242?

NP242NP231Horsepower: 243 hpHorsepower: 265 hp6250 rpm6800 rpmFull-timePart-timeLacks external locking hubsThe only part-time target case with external locking hubsMore gear options in low rageFewer gear options in the low range1-ton payload capacity2 tons payload capacity

It is a little hard to say anything straight while comparing NP242 and NP231 since both transfer cases are built with different purposes in mind. NP242 being the full-time transfer case is much more powerful than the NP231 which serves as only a part-time transfer case.

NP242 has applications in more tough applications like hauling loads, heavy towing applications, and tough trail riding. It can add more power than the NP231 and also offer better tolerance against extreme temperatures. On the other hand, NP 231 has better aftermarket support. The fewer moving parts and extra switch clutches reduce the overall maintenance requirements and chances of damage.

NP242 with more moving parts and linkage bending problems can put you in trouble. The aftermarket support is not good for 242 and rebuilding costs can be higher. If you ride in tough conditions like snow, NP 242 is a better option, of course for its power. Putting the NP242 in full time definitely worth it on the snowy and slushy roads.

It eliminates the need of switching back and forth on snowy and plain roads. The torque rating of NP231 is good and the 231’s 3-pinion gear set is rated for 600-lb-ft. NP242 is more versatile since its application is large and it works in both full-time and part-time modes.

We can safely conclude that NP242 is a better option for off-roading, trail riding, and towing. However, for everyday rides and light-duty applications NP231 with its better aftermarket support, low maintenance requirements, and impressive torque rating may win the race. Here is a comparison table that will further help you get an idea of which transfer case suits your needs best.

Major Difference Between The NP 231 And NP242

• NP 242 is the full-time while NP231 is the part-time transfer case.
• NP242 uses 6 pinion gears in the planetary for low range while NP231 uses 3 pinion gears.
• NP231 front yoke chain is 1-inch wide and the NP242 chain width is 1.25 inches.
• NP242 has 5 detents while NP231 has only 4 detents making their shifters entirely different from each other.
• NP231 features external locking hubs and NP243 doesn’t.
• The RPM rating of NP231 is higher than NP242.

Are All NP231 Transfer Cases The Same?

Not all NP231 transfer cases are created equal.NP231 has a total of nine versions from 1983 to 2001. All the variants of the NP231 t-case are identified by the serial number. The serial number has a specific letter at the end. The serial and part number of the transfer cases are usually mentioned on a sticker that is placed somewhere inside the transfer case. The nine variants of the NP231 transfer case are differentiated on the basis of the low-range gear readouts. NP 231 transfer cases from 1989 to 2001 are:

MP231, NP231A, NP231B,NP231C, NP231D, NP231E, NP231F NP231G, NP231H. NP231 being the oldest has no locking hubs and also lacks low-gear options. NP231A was equipped with internal locking hubs but it also doesn’t offer low-gear options. NP231C and later variants have low gear prevision and external locking hubs.

Frequently Asked Questions

Will A 231 Fit My YJ?

The latest versions of the top 231 offer a direct swap with YJ if it was originally equipped with NP242. The older variant of the 231 transfer case will also fit YJs with a little modification to the mounting brackets.

How Many Splines Is An NP231?

NP231 comes with 23 spline and 21 spline versions. Both of these spline options are available in long, short, and sometimes medium variations.

Is The NP231 A Good Transfer Case?

NP231 is one of the most reliable transfer cases ever produced. With incredible torque output, external locking hub, and provision of low gear options it is one of the best transfer cases that you can have.

Which Transfer Case Is Better: Internal V External Lock?

External locking hubs are better than internal locking hubs since they have more potential for towing, pulling, and hauling. Internal locking hubs have the advantage that they tend to engage at very low speeds of around 1-2 mph. If you have a manual transmission, an internal locking hub is better, but in an automatic transmission, an external locking hub is a good option.

Wrapping Up

I’m hopeful that this comparison guide will enable you to figure out what transfer case is best for your vehicle. If you are still confused you can put your queries on big jeep forums to get more concrete solutions. The choice of the transfer case highly depends upon the driving condition in which you mostly drive.