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I’ve been wanting to convert my 2.5 2wd to 4wd, and I have some questions on what I can do to complete this.
My idea is as follows: I found an AX15 from a dodge dakota 2.5, so it’ll bolt up to my 2.5 and i’ll have a transmission that won’t blow up like my other one.
Now, is it possible to swap out the output shaft to one that supports a t-case? Assuming I can, is it possible to add a t-case and then hook everything up, but not have it connected to a front axle, and then swap in a front axle later on?
Im looking to do this swap in two parts, the first being adding the transmission and t-case (NP231) and then adding a front axle and connecting it all. I just don’t know how good it would be to have a t-case hooked up properly but not connected to the front axle.
Are you asking if you can convert a 2wd to a 4wd ax15? Is that what you mean by "swap output shafts"?
Things to consider:
The NP231 transfer case can have a 21 or 23 spline input. Also, short, medium, and long inputs.
The rear axle ratio should be 4.10. You have to match axle ratios, and most are 3.55.
You'll probably have a hard time finding the correct length driveshafts.
And no, you don't have to have a live front axle when you install a transfer case. You can just leave it in 2H.
Here is a 2wd AX15 from a Dakota with the belhousing removed and a 4x4 AX15 from a Jeep, as you can see the whole rear section and shaft would need to be changed to convert to a 4x4.
And (if that's what you meant) if you do want to change the output shaft and tail housing, you'd also have to completely disassemble the whole transmission to do so. The output shaft (main shaft) has gears, bearings, and synchro hubs on it that have to be pressed off/on. It's not impossible, just highly impractical.
And (if that's what you meant) if you do want to change the output shaft and tail housing, you'd also have to completely disassemble the whole transmission to do so. The output shaft (main shaft) has gears, bearings, and synchro hubs on it that have to be pressed off/on. It's not impossible, just highly impractical.
I figured as much. I just want the AX15 on my 2.5 for when I either swap in a 4.0 or something else later on down the line, but unless I can find a 2.5 4wd dodge dakota, I don’t know what i’ll do. I’m not interested in converting to an AW4, and i’m not even sure if it’s possible to bolt one up to a 2.5.
As far as the gears go, how hard is it to find a front axle with 4.10 gears in it? I know for a fact I have the Chrysler 8.25 with 4.10 gears and (21?) spline input, and I can regret the front axle before I put it in.
But, i’m assuming that the driveshaft for a 4wd AX15 is shorter than the existing one I have, and what about the front driveshaft? Is it easier to find than the rear driveshaft?
Well, I just looked at car-part.com, and it appears only 2wd was offered with the 2.5 in a 1996 Dakota, so that leaves me with either finding one from a 4.0 4wd with an AX15 and buying a junk transmission from a 2.5 AX15 and swapping the bell housings, or getting just the AX15 from a 4.0 4wd and getting the bellhousing online, but that’s a 500 dollar part alone
If you have any local u-pull it places, keep an eye out on those Dakotas. They're more common than you think. There's a Pull-A-Part near me that I can sign up for text/email notifications.
If you know what you want, then start buying parts as you find them. I found a 2wd 97 xj in the yard here, so I grabbed the external slave bellhousing, pedal assembly, and crossmember. Later on, I found a 90 with a 4wd ax15. I just slowly gathered parts as they appeared until eventually I had everything.
Finding a front D30 with 4.10 gears already installed usually isn't that easy. You'll have better luck finding those in TJs. Normally, TJ (really, any soft top jeep) parts command a premium too.
If anyone can tell me by looking at this VIN if this Dakota has the 2.5. It looks like it by the pictures at my pick-n-pull, and it has a manual trans. only problem is that it’s a 2000. Should work, right?
Question… how am I going to find a driveshaft for the AX15 if I have the 2.5? Because the 4.0 is longer so the trans should be pushed back some, right?
Nah. The ax15 sits in the same spot regardless of engine size.
The driveshaft dilemma is simple. For the rear, get a hack & tap SYE for your NP231 and use an AW4 front shaft. For the front, take another AW4 front shaft to a driveshaft shop and have them cut it down by about 1.5".
Nah. The ax15 sits in the same spot regardless of engine size.
The driveshaft dilemma is simple. For the rear, get a hack & tap SYE for your NP231 and use an AW4 front shaft. For the front, take another AW4 front shaft to a driveshaft shop and have them cut it down by about 1.5".
Another question. I’m 99% I have the 27 spline 8.25 rear, and is the AX15 and NP231 27 spline also? And isn’t the front driveshaft shorter than the rear driveshaft?
I apologize for me asking all of these questions. I just want to make sure everything fits the first time
The rear axle doesn't make a difference for anything except gear ratios. The spline count you're referring to on the axle is the axle shaft splined end where it goes into the carrier. The driveshaft connects to the axle via U-joint straps. The spline count won't matter for that.
It does, however, matter that you get the right transfer case. 4 cylinders got a 21 spline input on their transfer cases, and the ax15 has a 23 spline output. But since you'll be using an ax15, just use the 6 cylinder transfer case with the correct spline count for the transmission.
The front driveshaft IS shorter. The real issue is that the ax15 is shorter than the aw4. (I'm talking 4wd to 4wd here) So if you try to find the correct rear and front driveshaft, you'll find yourself trying to source a longer rear (than the aw4) shaft and a shorter front one. If you do the hack & tap (check out iron rock offroad) then you can use a standard ol' run of the mill aw4 front shaft in the rear. The front driveshaft will be shorter than an AW4 front shaft since the AX15 is shorter. So you'll have to have an AW4 front shaft trimmed down a little by a driveshaft shop.
Or you can try to find a set of driveshafts from an ax15 equipped XJ, but every junkyard I've been to usually damages the rear driveshafts because they pick the cars up with a forklift.
I went through this same ordeal with my last XJ. Was way easier to just order some driveshafts through Adams. Like agreen said, the issue here is the AX15s odd length shafts and the fact that they are a lot more rare than the AW4s means good luck finding them in a good used condition.
What if I just used a 4x4 AX5 from a Wrangler? I imagine since a lot of the Wrangler’s were sold with the 2.5 and the AX5, that it would be a hell of a lot easier to source the proper driveshafts for it
01-16-2022, 07:51 AM
4wd conversion questions
