After rocking the 231 this winter, I can safely say that on icy roads my roommates 241 is awesome.

I have to shift the t-case way more than he does (just once), and his car is way more composed going through intersections and around snowy corners when under throttle. Best example is this unplowed roundabout that ices up like crazy at night. Mine sounds horrible going around in part-time 4-hi, and his sounds completely normal in fulltime 4-hi.

But, I dont doubt that the 231 is stronger off-road, just a trade off between on-road manners and off-road capability.

 

Ok, so I have a question here.


When doing some serious thick mudding - would I be best in 4 LOW or 4 part-time?


And what is the difference between using 4 low & 4 part time?


Ive got a 91 Cherokee, with the 242 and I run 33x12.50x15s


thanks

 

Low goes through a planetary gear which reduces the speed by 2.72 in both the 231 and 242. Torque however is multiplied. I have mudded in both high and low gear, you just have to go with what feels right in the situation.

 

I am so new to the Cherokee that I have trouble following all the acronyms.

but first and foremost, this FULL/PART time stuff....

so, the Cherokee is BACKWARDS to EVERY other shiftable 4x4?

when in "Full Time" in my Cherokee, I ONLY have 4x4 when there is wheel slip?
and when in "Part Time" my transfer case is locked into 4x4 the whole time?

(why would they label this backwards?)

 

2wd is obvious, part time is for offroad and slippery conditions like snowy roads, fulltime is anytime and anywhere.

 

The two names refer to usage scenarios, not how the mechanism actually operates. Part Time is suitable for use in only certain situations. Full Time is suitable for use in all conditions.

And both modes always engage power to all wheels. The difference is that Part Time locks front and rear drive shafts together, Full Time has a differential.

 

Ah.... I get it now!

thanks

I have new matched tires on mine, so never noticed any pavement hop when driving it in "PT"

as it is winter, and all the roads are snow/ice covered pretty much all the time right now, I'll drop it into "FT" and run it like that.

 

I just found this thread, and it has been very informative. One question lingers in my mind though, what is the swapability between both the 231 and 242? I have a 231 in my 91 but with all the snow we have gotten so far here in Calgary, the features of the 242 would be better suited for my use of my XJ.

Any ideas?

 

Easy. You need the transfer case, shift linkage, interior bezel, and the shift gate that sits under the bezel. You'll need to source an NP242 from a 91 or newer XJ so that the input gear is the same, although if you wind up with an old one you can just swap the gear over from your NP231. Good time to refresh seals and bearings!

 

That "Part Time" seems to confuse many people when they first try to figure out what it means. Once you wrap your head around it, it makes perfect sense.

 

Because if you're on a winter road with ice/snow patches it's a PITA to keep changing between PT and 2WD all the time. With FT you just leave it in 4WD FT and go.

 

Most modern day AWD systems are front wheel drive with automatic power transfer to the rear wheels when the ABS sensors detect wheelspin. That's not the same as the FT option on a 242.
FT drives all the four wheels all the time, but there is a differential between the front and rear drive shafts. With the diff, you can turn corners without tyre hop or - worse - the TC chain skipping over teeth. PT locks the diff so the TC then behaves like a 231.

 

I'll take the 242 all day every day.

I don't understand the claims that the 231 is stronger than the 242, because I've heard the opposite. But the 231 has better aftermarket support because it's more common. More companies make SYE's for the 231, while only Tom Woods makes an SYE for the 242.

I have a 242 in mine and the major difference is the Full Time option, which was already discussed in this thread.

 

It's an aftermarket perspective. Specifically, the NP242J is stronger than the NP231J (4 vs 3 rating from New Venture Gear). However there are several models of the NP231 that are much stronger, with upgrades like wider chains and additional planetary gears. They're all interchangeable. Also traditionally the NP242 only had a Hack-n-Tap SYE available.

On stock power though, or even mild upgrades, the only way to kill these boxes is by banging them off of rocks or running them dry.

 

Someone is giving away 242's ?? Put me on that list !