cmarr6

Okay guys, here goes. I am going to swap out my t-case in my '85xj. It currently has the 229 in it and I think it is going bad. It is making some noise when engaged. I like the AWD aspect of the 229 but don't think its strong enough. I swapped in a 355 chevy thats puttin out some pretty good horses. I still have stock axles and everything except about a "3 inch lift and some 31's. I take it pretty easy most of the time cause I don't want to start breaking things and don't have the money right now to swap axles or anything. I probably will down the road, but for now it's just the t-case. I don't do any serious wheeling cause there is just nowhere to go around here but I would like to start experimenting in the future. Right now it's more of a winter/blizzard truck to get me to work or just in to town in bad winter weather. We can get some pretty serious blizzards around here and I have a job that I HAVE to get to in any kind of weather. My question is, which t-case should I swap in? The 231 or the 242? I've done some research and either on will bolt right up if I get the right spline counts and shaft length, right? I like the options of the 242 with the full time or the part time 4WD, I have a '91 with this t-case and really like it, but is the full time option via the viscous coupling similar to the 229? I think thats a weak point and could go out on me in the future with all the power of the V8. Or should I go with the 231 with just straight Part time 4WD, which is stronger and can eventually put a SYE in. I am torn and need some expert advice and opinions. Which t-case do I go with?

Lowrange2

NP231. I hate the 242.

Bolt it up and forget about it.

VTJeep

What's up with the 242 dislike? Not as strong as a 231 is all I've ever heard.. Thanks. Well, that and the lack of SYE options..

cmarr6

Why don't you like the 242? not to start anything, just want some expert opinions on pros and cons of each one. For my application, winter driving and some light off-road use, I like the idea of a Full-time and part-time option. If I do decide on the 231, there are several different versions. What ones will bolt up without mods? I have a TH350 tranny that I put the Novak adapter on to fit the 229. It has a 23 spline input shaft, but don't know if that would require the long, medium or short shaft 231? how can I tell without taking the t-case off.

thakmfb

242 actually has a diff of sorts in it. This is usually what goes bad in them, especially when put under heavy stress. 231 is plain and simple t-case high and low. As far as your adapter situation, you may have to locate at t-case first, then call Novak and tell them what year the t-case came out of and they can guide you in the right direction on if you will need an adapter or not for your application. They have pretty good customer service.

NorCalJeep

I'd go with the 231, only because it has more aftermarket support than the 242 (and i have the 242).

andrewmp6

The 231 is stronger gm used them in the 4x4 s10 i have seen a few live behide a small block for years.What trans are you running tho?

cmarr6

I am running a TH350. I bought the adapter kit from Novak that included a new 23 spline output shaft to fit the 229. I also have a 91 limited with the 242 in it and I like it so far. Haven't had much opportunity to use the 4WD options yet as this is the first winter I've had it.

Brandon77

I have the 242 and have owned my Jeep for a little over a year now. The only issue going on with mine is it slips in Reverse on a heavy load... but i have a spare in the garage. Iron Rock just came out with a 242 SYE kit. I don't really use the Full Time option because i am not sure when to use it... i heard you can destroy a 242 by using the Full Time option and the wrong times.
What is the main purpose of the full time option and when do you use it? Because a lot of guys i know can drive just as fast on a part time 4x4 as a full time 4x4 option on these XJ.

xjheep92

Full time 4x4 can be used anytime. That's why the name is full time. It allows the front and rear axles to spin at diff rates under power so there isnt binding like part time 4x4. It's good for winter or if you don't want to switch back and forth between 2 and 4 wheel depending on the road conditions. Perfect for a dd in new England. Not needed for off road.

Brandon77

Now see that's the only time i have ever used Full Time is when im driving up the mountain on snow/ice with a lot of turns. Other then that i use Part Time on the trails only. Does using Full Time give you better MPG vs Part Time?
Thanks

cmarr6

That's why I am leaning towards the 242. I don't do alot of off road wheeling, mostly winter driving, but would like to start some off roading if I can find somewhere around here. Im just worried about the power of the 355 tearing it up when I do use it. I really liked the full time aspect of the 229. I'm thinking the noise might just be coming from the ball-in-a-can driveshaft in the front of the 229. Does anyone know the spline count of the front output on the 229 and what other yolks I can use to swap it to a yolk style output? I heard the '91 and up 242 yolk from an AW4 equipped XJ should work. Is that correct. What others? I think I will try that first to see if that solves the noise issue. But I want to eventually swap out anyway.

xjheep92

The other thing to think about is ride height and slip yoke elimination. If I'm correct the tcase you have now has a fixed rear output shaft. Both the 231 and 242 dont. If you lift past 3" your gonna need a sye. There's a lot more aftermarket support for the 231. You can do it with the 242 but you have to do a hack and tap or pay tom woods a ton of money to do a pro hack and tap for you.

I just swaped my 242 for a 231 with sye off Craig's list I picked up for $200. I would have liked to keep full time 4x4 but couldn't afford tom woods and don't trust the self hack and tap

mdnov

Having 2 Cherokees, one with the 231 and one with the 242, in my opinion, the 231 is stouter and has more aftermarket goodies for it. Less parts to break.

Lowrange2

Ah, missed this thread.


This is why I do not like the 242. ^ They break rather easily.