OK i want your honest opinion. I keep on debating if i should switch my np231 out and get something stronger or just keep it. How many of you have had troubles with it and what are the specs on you heeps. Have any of you put the 4 to 1 in it.

Well I have had my XJ with it lift for 7 years and so far I havent had any probs with it yet. I would like to change it to a D300 but why since its still doing great. I have 35's running with the Tcase and its still fine.........peace

Ive got an NP231 in my yj, running an auto TF-999 and 35's, with no problems yet. I also ran an NP231, behind my peugot for 2.5 years before I swapped to the auto. No a single problem.
Scott :grinpimp:<><

Bigbadjeep, with 38s you must already have an SYE in that 231. If you sell the 231 with SYE for $800 and add the $1000 you would have spent on the Tera4:1 you are only a mere $500 shy of an Atlas.
But you will want a longer driveshaft too since the atlas is about another 2" shorter than an SYE equipped 231

I am pretty much running the same setup as you big black and I decided to go for the atlas.. Why, have a weak point in your drivline? Thats what I say. I mean the 231 with the tera-low works fine I know a buddy that has it, and he likes it alot but he also wishes he did the atlas you know. I just dont believe in upgrading something, that you might want to swap out later anyway do it once and do it right, and your done.....

By the way thers like 80 post's about this same subject on the the" atlas or tera-low" post, check that out it will answer alot of questions....:beer: :beer: :beer: :beer: :beer: :beer: :beer:

Originally posted by bigblackjeep
OK i want your honest opinion. I keep on debating if i should switch my np231 out and get something stronger or just keep it. How many of you have had troubles with it and what are the specs on you heeps. Have any of you put the 4 to 1 in it.

I dropped a 32 spline SYE kit in to it. I haven't had any problems with mine, even after I changed from 4-lo/4hi/2hi without stopping. And have been hard on it just driving on the trail. no chain stretch or anything.

The 4:1 kit... not worth it. I was looking at the same, but I could easily dump my SYE'd NP231 for $600, and get an Atlas 4.3:1. With what will soon to be 38's, I already have driveline issues, that 2" will help alot (1350CV is running at 23.5degrees static)

Originally posted by Cheg
Bigbadjeep, with 38s you must already have an SYE in that 231. If you sell the 231 with SYE for $800 and add the $1000 you would have spent on the Tera4:1 you are only a mere $500 shy of an Atlas.
But you will want a longer driveshaft too since the atlas is about another 2" shorter than an SYE equipped 231
First, its 1badjeep, second, Im only running 35's for now. My buddy rockbuggy is the one you are thinking of on 38's. And you are right, If I followed what you have planned in the way of selling my 231 and such, but the problem is, trying to get 800 bucks out of an np231 with 180,000 miles.. good luck :) At any rate, for now the 231 is just fine for my application, and will be fine after the axle swap and SOA with 36-38" tires too.
Scott :grinpimp:<><

great transcase- i have wheeled with it for 2 yrs steady now. lots of ROCKS. i did the SYE/CV. even my peugeot is holding strong! :) not to say there isn't something stronger- there will always be something bigger/better than what you got. as long as you got the gears to crawl slow and don't gun-it the 231 will hold fine.

I should also add, Im running a 32 spline output shaft/SYE kit and driveshaft from high angle driveline, so Im sure this helps a lot too.
Scott

Originally posted by 1badjeep
I should also add, Im running a 32 spline output shaft/SYE kit and driveshaft from high angle driveline, so Im sure this helps a lot too.
Scott

That and dont forget most importantly his jeep spends 99.9% of its time on road and mall parking lots. Ya' dont need much strength for those speed bumps and curbs. :flipoff2: :flipoff2: :flipoff2:

Originally posted by Rockbuggy


That and dont forget most importantly his jeep spends 99.9% of its time on road and mall parking lots. Ya' dont need much strength for those speed bumps and curbs. :flipoff2: :flipoff2: :flipoff2:

True, the np 231 with the 32 spline kit is plenty strong for the speed bumps, but his 35 might just :nuke: under the strains of a curb:D :D :D

fuh me tommy, is that a 231 in yer trousers? *snatch*

Just put aside $30 per paycheck for an atlas2 for the next 2 and a half years . I know you have atlasII envy. We all do. :D

231 is good for a while till you break that sweet chain in it so save and go Atlas or ORD doubler.

Originally posted by mfg4rox


True, the np 231 with the 32 spline kit is plenty strong for the speed bumps, but his 35 might just :nuke: under the strains of a curb:D :D :D

WOW.. always gotta be bringing that up eh? Im not even going to comment, except for this... we can't all be as "rich" as you.
Scott

While the AX-15 & NP231 aren't BAD gearbox tranny combo...My current TJ shopping cart is looking for a T18 & dana300 combo....

Mine has never given me any problems.

258/BA10-5/231w/Currie SYE.

Jake

When I bought my YJ I discovered that my NP231 had a hole in the bottom and had NO fluid in it. It had been run dry for god knows how long! I patched the hole and filled it up and ran it for six months with no problem till I replaced it with another 231. No problems at all! Its a tough Tcase! Also, it would seem that if the gearing is correct that larger tires should not stress the tcase or tranny, only the axles. Of course that is not true if your tires are too big for your gear ratio. Thats my opinion, correct me if I am wrong..