TeraFlex 4:1 reduction or NP241

[03silvertj]

Originally Posted by mrblaine

Before I did either of those cases with your drivetrain, I would get a doubler in front of the t-case, cut the motor mounts loose and slide the motor forward exactly the depth of the doubler.

No driveshaft mods, you have the room, you can modify the fan shroud, you can bend the trans shifter, and you need all the gearing you can get.

The Rubi case while being a great case, is a pig. It's not much smaller than an Atlas II and it's only 4-1. I've installed a few, the customers are very happy, but it's still a pig.

That is a great idea, I don't think I would have to modify the fan shroud either because it is an electric fan and the shroud may be a total of three inches long with a good 10 inches between the motor and shroud.

However... I travel a lot for work (by a lot I am gone 80% of the year) so this upgrade is going to be about 5 days before a trip to NC and AR with some friends for some wheeling. I know it probably isn't the smartest thing to choose an upgrade based on the amount of time it takes to install. But right now that is the case.

Honestly I think what I will do is go with the 241 or the Tera still (No still haven't made up my mind) and move the motor forward and add the doubler the next time I am home to work on the Jeep, because you are right with this motor I do need all the gear I can get, which is why I am wanting to do the 4:1 before the trip. I am tired of feathering the clutch, and that is with 4.88's in the diffs. Again thank you for that idea!

Kyle

[03silvertj]

Originally Posted by 2nuts4u

terra is junk!! i went rounds with them on my kit..there warranty well there is none.they have a clause that says you cant go over 25mph with it in low.my kit lasted 2 weeks..junk junk junk..i tore it apart and the little bronze bushings are cheap junk.
get the rubi case...32 spline outputs.wide chain,1350 yokes,10 times stronger case. there is no comparisent to the terra 231. the rubi case is 100 times better.

You also have a good point! About the yokes and overall better strength of the case! I think if I can find out if a drive shaft place in my area has a turn around time of less than a few days I will go the 241 route. I don't mind if the spedo doesn't work for this trip, but kinda need those drive shafts!

Also out of curiosity, what motor did you have when you trashed the Tera? As mentioned earlier I only have the 2.4L, which I think has a peak hp of 142 at the crank...

[nasvik]

Originally Posted by 03silvertj

The 2003-2006 model year SE's with the 2.4L have a NV1500 transmission which has the same spline count as the tranny behind the 6cyl. So in my case I could use one, unlike the 2.5L which had the AX-5 and a 21 spline out put shaft. So yes it was just the older 2.5's that you couldn't.

While I know you're right on the spline count, double check the length of the trans output shaft. At one point there was a difference between auto and manual transmissions. I had to get the correct 23 spline input gear for the tera case.

Originally Posted by mrblaine

Paul, try bumping up the vent tube size to 3/8"

Good idea. Will do that this AM before driving a smoking rig across the Bay Bridge to work again...

Paul

[stealthjeep1]

I had a Teralow 4:1 kit in my 97 TJ behind my AX-15. Mine was noisy too. Only in Low Range, but noisy yes. It was worse before it broke in some. Never had any leaking issues from mine, but the main input bearing at the planetary's failed twice. The first time it failed, I contacted Teraflex and they warranty'd it as it was within the time constraints. While they had it, they replaced my chain and all the bearings in it as well. All on their dime. A couple years later it failed again. You could have taken a picture of the two failures and not been able to tell the difference. I tried to get a hold of Teraflex with no success. Email, phone call. Nothing. So I went to Advance Adapters and purchased a 4.3:1 Atlas II. Much happier with that. As for your case, I would go with the 241 if possible. I have heard pretty good stuff about that TC.

[robert-r]

Originally Posted by 03silvertj

Was there a possibility that it was overfilled that caused it to puke ATF from the breather? To hot?

Nope. It had the correct amount of atf in it.

[03silvertj]

Originally Posted by nasvik

While I know you're right on the spline count, double check the length of the trans output shaft. At one point there was a difference between auto and manual transmissions. I had to get the correct 23 spline input gear for the tera case.



Good idea. Will do that this AM before driving a smoking rig across the Bay Bridge to work again...

Paul

I did check on that as well. I found a thread on the "other forum" where a fellow 2.4L/NV1500 owner had measured the output shaft to be 1 and 3/8ths inches. Which is the short input. TeraFlex also confirmed this.

[mrblaine]

Originally Posted by 03silvertj

That is a great idea, I don't think I would have to modify the fan shroud either because it is an electric fan and the shroud may be a total of three inches long with a good 10 inches between the motor and shroud.

However... I travel a lot for work (by a lot I am gone 80% of the year) so this upgrade is going to be about 5 days before a trip to NC and AR with some friends for some wheeling. I know it probably isn't the smartest thing to choose an upgrade based on the amount of time it takes to install. But right now that is the case.

Honestly I think what I will do is go with the 241 or the Tera still (No still haven't made up my mind) and move the motor forward and add the doubler the next time I am home to work on the Jeep, because you are right with this motor I do need all the gear I can get, which is why I am wanting to do the 4:1 before the trip. I am tired of feathering the clutch, and that is with 4.88's in the diffs. Again thank you for that idea!

Kyle

If any of you are looking for the Box 4 Rocks AND a Dana 300, there is one for sale on the Inland Empire Craig's List. No affiliation, don't know the condition, but at 800 bucks, you're getting what looks to be a working 300 for 300 bucks. About the going rate for one that isn't trashed.

[01tj]

ive got a 2.5 with 488s and a tera low kit on 37 krawlers and works great. like said before i run synthetic atf to make it quieter

[03silvertj]

You guys keep mentioning the speed limitations for the Tera unit in 4low. Don't our stock transfer cases have the same limitations? I know the limit in 4hi is 55mph, I don't have my owners manual to reference it right now.

Really though, if I have to travel faster than 25mph I would be in 4hi.

I am still leaning toward the 241 though just for the upgrade in strength over the 231 overall, depending on the drive shaft turn around in my area.

[Bruce T]

Its not the speed so much as the input rpm. After mine exploded tera told me that it isn't supposed to be spun faster the 2500 rpm's. You can achieve that with any motor in low range. I personally know of 4 blown tera lows (one was mine) but I live in michigan where snow, mud, and sand are everywhere. I love my Atlas!

[03silvertj]

Interesting. Well spinning 2500 rpm's it another thing, you could do that climbing any ledge if you got happy with the skinny pedal. Makes me lean even more toward the 241...

[Flash- '00 TJ]

Originally Posted by 03silvertj

Interesting. Well spinning 2500 rpm's it another thing, you could do that climbing any ledge if you got happy with the skinny pedal. Makes me lean even more toward the 241...

It's not that you can't exceed 2500 RPMs. They just don't recommend it be done for extended periods of time.

Here is what it says in the installation guide:

High RPM Warning
Do not exceed 2500-3000 RPM for sustained periods of time when using the Low231 in low range.
Avoid high engine speeds when using the Low231 in low range in 4th or 5th gear with manual transmissions or with high gear automatics. This is common when driving in snow, mud, or sand. Because the gears are turning 50% faster and with the high gear ratio, it is possible for input speeds to reach 6500 RPM and cause damage to the transfer case.
We recommend using a lower gear in high-range for higher speeds rather than running the Low231 at extreme RPM’s.

http://www.teraflex.biz/low-231-hd-t...ong-input.html

[targa3859]

the 241 OR is hands down a better t-case it is stronger, you can switch gears without being at a dead stop, you can run at over 2500 rpm the gears and chain are much bigger and stronger, should be an easy choice?

[JustinSuth]

i know its a little OT but is there a 21 spline input for a 241ORfor us ax5 guys?

[03silvertj]

Originally Posted by JustinSuth

i know its a little OT but is there a 21 spline input for a 241ORfor us ax5 guys?

I don't think so. The Rubicon came out as a 2003 model which was the same year Jeep switched over to the 2.4L SE with the NV1500 5 speed manual which has the 23 spline output, then all of their transmissions has 23 spline outputs.

Maybe look into Advance Adapters?

[2nuts4u]

i run a stock 4.o. please listen and don't waist your money on a terra low kit..you will thank us later.

[lethaljeep]

Originally Posted by nriver

What ever you can find cheaper.

On that note I picked up a Tera 4:1 from Sam's offroad for around $850. Works great, no noise... well except at higher RPM's in low range.
They sell blemished ones that are cheaper and the only thing I noticed was that mine wasnt all shiney when I got it...
They only have these blemished ones from time to time so you would just have to check every now and then to see if they have any in stock.
http://www.sams4x4store.com/index.html

[SanDiegoCJ]

Originally Posted by Bruce T

Its not the speed so much as the input rpm. After mine exploded tera told me that it isn't supposed to be spun faster the 2500 rpm's. You can achieve that with any motor in low range. I personally know of 4 blown tera lows (one was mine) but I live in michigan where snow, mud, and sand are everywhere. I love my Atlas!

I know a guy that blew up his Tera-Low gears in his NP231 4 times.
The last time it fractured the case. He gave up in disgust and bought an Atlas II.

[Jeepman14wheel]

I have had a Tera Low for 5 years now, never even thought about the RPM limits. It is noisy but has never given up on me or puked out ATF fluid. I cannot say I have been nice to it at all...

[03silvertj]

Because there is little info out there about t-case swaps with my motor and tranny combo, I want to keep this updated for the next guy.

I know some of you are going to think I'm an idiot, and we will see I guess. I ended up going with the Tera unit. My reasoning is that I have about 5-6 days from the time I get home to the time the trip is to get everything ready, so I really didn't have the option to spend time getting drive shafts/yokes adjusted for the NP241.

I am going to continue to keep the thread updated. If I break it I'll let you fawkers know!

[03silvertj]

As I promised, I am going to update this thread. I know it's kind of old now but when I started researching this there wasn't much info, so I want to pass this on to others.

As I said, I went with the Tera 4:1 kit. At the same time I purchased and installed a SYE with the tom woods drive shaft. There was some confusion however with which part number I needed because there is almost no information available on the NV1500 5 speed manual transmission used in the 2003-2004 Jeep Wrangler SE's with the 2.4l DOHC engine. The part number needed ended up being "2104303" which is the 23 spline short input.

Installation wasn't too horrible. I did it all by myself on my garage floor with basic hand tools. I have NEVER done anything related to gearing before. So if you have some mechanical knowledge, I say it can be done.

Use: Well so far so good!!! I went on a recent trip to CO and really beat the heck out of it! I had a great time. The only problem was with the linkage. It was popping out of 4wd low every once and a while, that was resolved when I got home. The next off road test was at home in FL for a whole day of blasting through the mud holes at Richloam, I spent a lot of time in 4wd low at high RPM spinning the 37" pitbull rockers with no problems.

DISCLAIMER!!!!
I only have a 2.4l four popper... Not much power, which may have been my saving grace for not breaking it.

All in all, I am very happy with my purchase.

[Junior F-Nis]

Nearly July, hows your Terra kit doing? I'm looking to out either a 231 with TF in, or install a 241OR (if I can find one) in my 98 ZJ with Auto. Not sure if anyone has has experience with the ZJ 44RE auto working with the 241OR???

[bigbaggedbeast]

Originally Posted by going_postal

I have heard both good and bad about the Tera-Flex kit, some say no problems and have or are running one, and others say just a problem waiting to happen. Anyone have any real info to share?

it's a ticking time bomb i have seen to many break the case welds on the planetary gear when this happens if they have parts your only down 650 bucks IF they have them on the shelf of course they don't because so many break id put a max tire size of 35's on the unit if your ever going larger go a different route ..

[jeepinnorcal]

Originally Posted by 2nuts4u

i run a stock 4.o. please listen and don't waist your money on a terra low kit..you will thank us later.

X2 waste money big time

[Junior F-Nis]

Originally Posted by bigbaggedbeast

it's a ticking time bomb i have seen to many break the case welds on the planetary gear when this happens if they have parts your only down 650 bucks IF they have them on the shelf of course they don't because so many break id put a max tire size of 35's on the unit if your ever going larger go a different route ..

I think I've heard enough to turn me away from the TF kit. Trying to find out more about the 241OR (Rubicon T-case). My project just started this week on the ZJ, pulling the 249 case will tell me if I have a 23 spline or not, if so and the 241OR is a poss. I'm going with it. A grand saved over having to buy an Atlas is a grand for more cool parts.