Thinking about '86 MJ purchase..Swap 4.0 in?

[Incommando]

I am looking at an '86 LWB with the 2.8/AX5/207 drivetrain. Truck is decent but I am not in love with the drivetrain.

 

I have a '91 4.0 MJ as a donor for the 4.0, wiring, any front sheet metal that needs changing, and the TCM for an AW4. As the '91 is 2wd I have a later 23spline AW4 and matching 231.

 

Searching for swap gives me too much info ( around 10,000 returns) as the search function automatically ignores 2.8 and gives me everything with "swap" or "swapping" in it. I have read until my eyes are bleeding.

 

If anyone has anything bookmarked or advice I would appreciate it.

[btm24]

Try googleing it :-)

 

Its a very hard swap, looked into this before when a friend was looking at a 86. If I had my computer up ans running I would pass you a few links :fs1:

 

Brandon

[Pete M]

everything need to be changed, including: drivetrain, fuel pump, all wiring (interior too), hood and latches, etc, etc, etc. basically you'll be completely gutting the truck. :thumbsup:

[knever3]

3.4 from a firebird etc.

[Incommando]

Much worse than a Renix to OBD 1 swap?

 

The problem with the 3.4 is the AX5... :(

[Incommando]

found some info out there that the '86 MJ does not have the same firewall as an '86 Xj and does not have the same swap issues. Does anyone have any info from someone who a=has actually attempted this swap?

[mpace6a]

I have an '86 with the 2.8 in it, and posted on here a couple months back, basically, everyone said don't do it. You have to either play thor with the firewall, or cut and patch because it is shaped differently on '86 mjs :mad:

I originally intended to do the swap, but once i realized just how much cutting and fabricating went into it, I bailed and sold the parts XJ and bought a new 2.8 from an S10. If you have the fab skills needed, go for it, but I think you'd be better off with a camaro/firebird 3.4, which i was told would bolt up to the ax5. I personally went with the 2.8 again just as a quicky motor to get it on the road(still hasnt happened) until i can afford a mercedes inline 5 turbo diesel, or a bigger v6 and tranny.

here's the thread i posted a few months back, has some pics and more details i may have left out, hope it helps!

viewtopic.php?f=2&t=32881

[Incommando]

Thanks for the link. I am going to bite the bullet and do the 4wd swap on the 91 as I already have all of the pieces. Well, I had all of the pieces but sold them or lost them and now I have them again.... :D

 

I don't think the 3.4 will get me where I want to be namely a tow vehicle for the CJ. I will just have to live with the '91's rust or get the body done.

[Pete M]

just so you know, MJs don't make a great tow vehicle for other vehicles. they can be made to work, but there are much better and much safer rigs out there (pretty much any reasonably modern v8 fullsize truck will brake better, pull better, and weigh more).

 

but if you insist on this path, I'd highly recommend a double brake booster and rear disks. :thumbsup: and a 242 t-case so you can pull in 4wd.

[Incommando]

Well I am part of the way there as I have a '95 dual-diaphragm booster to swap on and my choice of 231 or 242 x-fers. The rear axle will be a 29-spline 8.25 I got from under a '98 XJ while the front is from the '95 the booster/m.c. came from.

 

The '91 was a great buy at $200. I have driven it on round-trips of 400 or so miles without a hiccup. The body is rough although the cab floor is surprisingly in good shape.

 

I am thinking of selling the KJ, which is actually a decent tow vehicle probably due to its 4000 # bulk, and picking up a new/newer DD. The MJ would become the occasional tow vehicle plus the inclement winter driver, another plus for the 242.

 

Decisions decisions.... but either way the 2.8/ax5 '86 no longer seems to be an option.