Teraflex 4:1 Transfer case...
- Thread starter Loopy
- Start date
Just saw this.
I have personally had to rebuild three of these for a friend. One failed on Fordyce trail, had to get a stock 231J and swap the SYE off the Tera 231J case on the trail on my back under the Jeep over a holiday weekend. These are very susceptible to over-revving in top gear with the low range 4:1 planetary pinions failing. This shoots metal shavings throughout the case totally ruining the bearings, syncros and other parts when that happens. They will NOT warranty over-rev damage and consider it abuse if this happens. They will sell you a replacement at reduced cost but not cover damage caused by driving around in 4th or 5th gear 4:1 low range if you over-rev the box. There are warnings in the manual and on their website regarding this condition. Then again, I had another friend that never had any problems with his because he was overly anal about the over-revs in higher transmission gear ranges so if you have control over yourself, it is a cheaper option for lower crawl gearing. YMMV FWIW.
Other options if you are really desiring a 4:1 transfer case, consider these here:
A used Rubicon Rock-Track NVG-241OR 4:1 transfer case out of a 2003-2006 Rubicon model TJ/LJ. Used, these run about $1500-1800 give or take. I wouldn't pay any more than that because if you add about $800 to it, you're in Atlas II price ranges then. Best option if you flat tow your Jeep and want a strong quiet TC. Add a Tera-2-Low conversion kit to it for another $250 and you're G.T.G.
~~~~~OR~~~~~
An Advanced Adapters Atlas II in 3.8:1, 4.3:1 or 5:1 ratio. Gear driven, super stout, Twin-Stick control. Best there is PERIOD. 4-Speed models available for longer wheelbases. Flat tow capable models with an oil pump are rumored to be coming soon. Nuff said!
I have personally had to rebuild three of these for a friend. One failed on Fordyce trail, had to get a stock 231J and swap the SYE off the Tera 231J case on the trail on my back under the Jeep over a holiday weekend. These are very susceptible to over-revving in top gear with the low range 4:1 planetary pinions failing. This shoots metal shavings throughout the case totally ruining the bearings, syncros and other parts when that happens. They will NOT warranty over-rev damage and consider it abuse if this happens. They will sell you a replacement at reduced cost but not cover damage caused by driving around in 4th or 5th gear 4:1 low range if you over-rev the box. There are warnings in the manual and on their website regarding this condition. Then again, I had another friend that never had any problems with his because he was overly anal about the over-revs in higher transmission gear ranges so if you have control over yourself, it is a cheaper option for lower crawl gearing. YMMV FWIW.
Other options if you are really desiring a 4:1 transfer case, consider these here:
A used Rubicon Rock-Track NVG-241OR 4:1 transfer case out of a 2003-2006 Rubicon model TJ/LJ. Used, these run about $1500-1800 give or take. I wouldn't pay any more than that because if you add about $800 to it, you're in Atlas II price ranges then. Best option if you flat tow your Jeep and want a strong quiet TC. Add a Tera-2-Low conversion kit to it for another $250 and you're G.T.G.
~~~~~OR~~~~~
An Advanced Adapters Atlas II in 3.8:1, 4.3:1 or 5:1 ratio. Gear driven, super stout, Twin-Stick control. Best there is PERIOD. 4-Speed models available for longer wheelbases. Flat tow capable models with an oil pump are rumored to be coming soon. Nuff said!
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crackedcornish
TJ Enthusiast
Tj04
TJ Enthusiast
Tj04
TJ Enthusiast
Follow up question: if one had a 4:1, at 1500 rpms would it actually be much better than a 2.72:1 at say 3200? Jerry had told me under 2000 is lugging the 4.0, and it isn't getting its peak torque. Not sure if it applies to 4lo
crackedcornish
TJ Enthusiast
which would you rather have a broken tereflex 4:1 or a working 2.72 in your stock 231...if you must have 4:1, save your money and get an atlas, or at least a 241
Just to keep folks updated, Tera no longer makes or supports the 231 4-1 conversion either in parts or service. They have a small selection of parts left they will continue to sell until they are gone but after that, no more.
Why? They are big, expensive, you still need new drive shafts to convert to one, and when you are done, you still have a big heavy case that you can't twin stick. With the average cost of a used one nowadays, you're better off taking a very hard look at an Atlas. (and I'm no fan of the Atlas, they are big, heavy, expensive and not worth it, but if you going to piss over the "not worth it line" and hit a 241, arch your back a bit more and piss on the Atlas)
derekmac
TJ Addict
@mrblaine what would you recommend over an Atlas or 241? A buddy just had his 241 blow apart on the highway on his 06 Rubi, so he's looking for a new case. From what he's found, an Atlas isn't much more than a 241. He hasn't looked into other options as far as I know, but if there's something better, I'd like to be able to pass the info on to him.
The only other decent option is a flipped Dana 300 with a 4-1 gear set and twin sticks. By the time you find one, convert it and get it working you'll have Atlas money in it.
If I blew up a 241 and liked it, I'd try to find another one so I wouldn't have to redo everything.
Was he flat towing?
derekmac
TJ Addict
OK, thanks, I'll let him know that option as well. He'll probably end up with another 241 as the Jeep is his DD, and he was told it would take 5-6 weeks to get an Atlas.
No, he was driving it, said he heard/felt a loud bang. He pulled over, looked under it, and the case was split in multiple places.
The odds are 99.99% that he had a front driveshaft that has been chirping that he ignored. When the centering ball froze and locked up, it does so at an angle because the front axle is lower than the t-case. That acts like a big long handle wrench and just twists the case until it explodes and rips the whole left side off of the rest of the case. Forensic examination of the upper double cardan should reveal it locked up solid.
BLUF: The 241OR is a great choice for the everyday TJ guys/girls like most the members on here are. I'm a fan of a built 300 or 205 and of course an Atlas. I would venture that most members here don't need twin sticks. A 241OR is as close to bolt on as it gets and the user gets the awesome 4:1 gearing. Sure the others are awesome, just didn't think most guys here would need twins. Nothing wrong with them. I run a built 205 in one of my Crawlers and came from a JB built 300.
I'm a big fan of the 241OR. The Teralow kit has a history of having issues and not staying together. Teraflex doesn't even support the 4:1 231 kit any longer. So that rules out the 4:1 231. The easiest next option is a 241OR, yes it requires a front driveshaft and a rear driveshaft mod. But the rear slip yoke should be eliminated IMO on any TJ running 31" or bigger anyways. So it should just be a front ds mod and cable shifters.
The Dana 300 can be built by JB or any other supporting brand. But it also requires an adapter to bolt up on top of the 4:1 kit, plus the rebuild and any other mods you want to make it catered to your Jeep/application. The cable shifters are required for both cases. Plus there 300 has been known to have a weak case. Again the 241 shines via price point and ease.
205 is a great case but even mentioning the Dana 300 is starting to get into the more hardcore rock crawler realm much less a built 205 or Atlas.
The 241 is great for a TJ that is stock up to 35's. After 35's (IMO) its time to go a little more hardcore and stretch the wheels and swap in a better drivetrain to include something like a 300, 205, or Atlas.