Comanche 2wd to 4wd

After about an hour of searching I have really more questions then I started out with. So here we go.

Im thinking of buying a 2wd '90 MJ. It has the I6 and Ax15. If I buy it I was going to do a Aw4 and NP 231 swap on it. So here are the questions:
-What years would I need to use for the donor parts? If I keep the tranny and tcase together, will it matter what years I use?
-Just how hard is it to wire a automatic from a manual? Is it unplug, plug and go? Are there any things that I dont need? This will be a trail rig, so I dont care if any lights go on.

My main worry are all the electronics that are involved. I dont know what they do, where they go, or anything. I need help, in more ways then one. Thanks for your time.

If you can find a cheap donor vehicle for the 4WD parts, that would be best. You'll get all of the little widgets, brackets and wiring that will nickel and dime you to death at the boneyards. Also, think of it as a 3-D wiring diagram/FSM.
BTW, I'm in the same boat right now. Got a 88 MJ body (thanks again, Pete) for free and am swapping the driveline and wiring out of a 91 XJ in it to make it a HO and 4WD. Needless to say, the wiring is freaking me out.....

Going from a stick to an automatic should be fairly simple. If you find a 87 - 90 4WD donor you need the front axle with vacumn setup and I beleive the TPS wiring and switch, also the NSS switch wiring. Under the passenger side dash you need the TCU; I don't know if the under dash wiring has a plug-in for the TCU (seems like the harness has everything - would make sense to have only 1).

It would be much much easier if you bought a 2wd auto to begin with, but the stick-to-auto and auto-to-stick swaps have been done before. They aren't for the squimish though. Either way, I highly suggest a shop manual if you're doing any wiring changes. Chiltons/Haynes sucks BIG time in that department.
Jeep on!
--Pete

ComancheClub.com

Slightly different animal, but I converted my '98 ZJ to 4wd. I had no choice but to use a '98 42RE because of electronics issues without it costing me bundles of time and $$$. The other hard parts, T-case, front axle... I sourced from around. I'm on my 3rd D30.

I didn't want headaches on wiring, so I kept it simple. You really should use a FSM to get the real details on the wiring.

I converted my 94 XJ to 4x4 about 6 months ago, useing a 89 XJ.

Although both were Auto trans. Wiring and controls were the same between the years. Swapped the front axle knuckles, brakes and bearings to the disco axle.

If you want any specfic pic's or questions PM me, I'll help if I can.

I swapped in a non computer controlled auto trans in my 2x4 to 4x4 conversion. It's only a 3 spd but that's what I wanted. 87 MJ 2.5L TF904 trans. any 23 spline input NP231 bolts to the TF904. The TF904 won't work with the 4.0L application due to the diffrent bolt patterns on the bellhousing.
I can check my Advanced adapters book to see if they make an adapter.
I doubt it... The hardest part was locating the tone ring for the CPS and fabbing up a mount for the CPS. This rig is trail only as well.

the wiring is doable, but a pain, so I didn't do it on my manual-to-auto swap, I just made my own tranny electronics. the mechanical portion is very straight forward.

The 904 torqueflite in wranglers (998 or 999) behind a 258 is a direct bolt on to a 4.0 block - same bolt pattern - no electronics except NSS. I have on behind the 4.0 in the MJ

I'd stick with the AW4. Drivetrain length is not an issue like wranglers, the AW4 is generally cheaper, the AW4 is stronger and more durable, and OVERDRIVE! do what it takes to swap the electrical, or build your own controls, or PM me about controls.