Almost a guaranteed to find a 241 next to or in the bed of a pickup at the local u pull it yard. Great for 6 pinion planetary gears. Just make sure of the gear cut changes. They changes around 94’.
NP 231 Transfer Case Upgrades?
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- np231 rebuild transfer case
i was gonna try and put 1 together for that 205 under drive, if i can find the donors cheap.
I have the Tera-Low. I don’t think it was poorly designed. People just didn’t use it within the clearly stated parameters. Even now I’ve yet to see anyone accurately state those parameters on this forum, which are clearly stated in the Teraflex paperwork.
It is true that it has no support as of 2018.
just toss them bitches over the fence.........................around here, i tell um i'll buy all their busted units for 35$ea and they'll be out back with a hammer this afternoon.
Are you swapping the 241 planetary guts into the Jeep planetary? I ask because the 241 should be a 26 or 32 spline, where the Jeeps are 23/21 yeah? It's been awhile though.
You can also get a 23 spline planetary to swap the entire thing into the TJ case, from Dodge 231s, they also come with the wider chain set. Also have to pay attention to input stickout, there like 3 different lengths. Also the aforementioned sun gear cut changes.
That is the input. The planetary will slip right in using your existing parts as long as they are all after 94’ gear cut change.
Copy that. After I got a YJ-TJ gear cut swap problem (found out the hard way), I've never mixed the inputs and planetary. THanks for the info.
I meant grab the 6 pinion planetary from the Dodge, it'll also come with a 23 spline input, those actually may be cheaper than the 241s that always rub a hole on the case.
Right now I'm dealing with this to adapt a 231 to a 4L80 trans. We need to swap in the 32 spline input into the 231. Appreciate the help.
Should only need a 32 spline input. eBay has lots. Just make sure of gear cut. I think the gear cut can be verified by wide or narrow bearing on the input as well.
Last one we did on Kevin's was swap everything in to the 231 from a good JY 241 case, 7/8 clocking ring, and he slotted two holes in the trans, because the pattern was off.
This one we will be doing the AA short adapter, and doing a 32 spline input with 6 gear in his 231. Will be straightforward, if the 4WD output has enough length on it. If not, will have to get a 2wd trans and cut down the output. Customer wants an Atlas later, so I want to keep the 32 spline trans output.
It’s just a stronger change a gear, no lower ratio is gained unfortunately.
There was a design problem which allowed the planetary gearing to implode on itself if ran at too high of RPM's but as you are finding out with that lower gearing 90% of the time you really don't need to spin it that fast anymore. Having lower gearing allows you to drive with greater control. As you know the one time you want wheel speed is in mud or snow. And like I said I rev'd mine above that 3K threshold more than once with no ill affects. What exactly was the reason they would implode I don't know.
I would guess that the planetary gears just spun faster than their sleeve bearing could handle with the lubrication it was given. A little spitballing here, because I haven't compared it to a 241OR to see the size of the planet gears, but in order to get the 4:1 ratio within the constraints of the size of the case, Teraflex used a two step planet gear that had a very small gear interfacing with the annulus, and a larger one interfacing with the input gear.
Based on how little those gears look to the eye, I would guess they spin considerably faster than the 231 or 241OR do. I just don't know if that, or the pinion bearing design was the larger contributor.
Am I setting myself up for failure by thinking a front electable hub kit could get a TJ/LJ 2 low?
Pop the factory 231 into 4 low, leave the front hubs disengaged, and you have 2 low....
Pop the factory 231 into 4 low, leave the front hubs disengaged, and you have 2 low....
I honestly do not know. But your SWAG is as good as anything else.
That is more or less what the 2LO low kit is doing except that it's disconnecting the front drive inside the transfer case.
As has already been said the biggest improvement to the 231 is to swap out the 3 pinion planetary for a 6 pinion planetary.
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