MF Steve!

Changed out the front inner corners to accept a 4.0L radiator and crossmember today. I skipped swaping the front frame crossmember, because I plan on doing the hidden winch, which will sit behind the bumper. The new crossmember will be 4" x 6" x 5/16" angle iron, and the radiator can sit right on top of that. Also dropped the motor in w/ the AW-4 attached, slid the mount bolts right in, and got all the rest of the wiring clicked in! A few better than Motorola Q quality pictures:

Never thought of that, thanks!

Now that I have the 4.0L and AW4 transmission in my '86 MJ (previously 2.5L and ax-5, 2wd,) I've noticed a major concern with the stock transmission crossmember. The question is basically this: Were there different crossmembers for different engine/transmission combinations? Or, is it the mounting locations on the uni-rails that are the difference? Right now the location that the crossmember bolts to is about 2 1/2" too far forward against the location of where the transmission mounts to it. Any insight would me most appreciated...

Am I missing something? Did you do this also? If so, I had no idea, and just thought it would be unique!

Thanks man...your build thread helped tremendously when looking into what was involved in the dash swap!

This is something I was concerned with up front. After removing the 2.5L, and looking at where the mount locations on the block are, they are very far forward. The 4.0L mounts are in the same exact spot, just more "balanced towards center on the block. I pulled the mounts and plates from the XJ, just to be sure, and have something that was in much better condition. So to answer your question in the simplest of terms, 2.5L and 4.0L use the same mounting locations, just pull the brackets and mounts from your 4.0L donor vehicle.

Alright, I'm bringin it back from the dead! I've made a good bit of progress since I joined up here/posted this thread. I've been leasing a 2000+ sq. ft. shop to work on this pig, and damn is it nice to have room to move, and not clutter up the garage at home! I've only really been working on it for the past month or so, but it has come a long way, and I've made lots of changes to my plans. I also have to say, the whole '86 firewall thing is blown WAY outta proportion. I massaged my firewall approx 3/4" and the 4.0L dropped right in. It's not even a clearance issue involving the head, it is the last tab coming off the back of the exhaust manifold that does the contacting. Anyways, don't be so discouraged about the '86! I bought an extremely mildly hit '99 XJ sport, 4.0L, 4x4, aw4, power everything, for $500. It was stripped of anything and everything I thought I would need or be able to sell, and it's now all in the MJ. What's been done so far: '86 MJ stripped '99 XJ stripped '86 MJ engine bay cleaned and painted black Transferred complete '99 wiring harness, PCM, and all accessories to keep everything working in the '99 style (keyless entry, power everything, even the multi speed wipers, etc.) '99 Dash conversion 4.0L swap (motor hot washed, painted CAT yellow w/ black accessories, header coated, and all accessories cleaned and re-installed) As far as changes go, I've decided to make my own front long arms, I'm sticking w/ the AW-4 for now (affordable,) keeping the NV231 transfer case. Here's a couple pix, I never take a lot...I'd rather be getting stuff done!

I too have wondered about this. I kept the front half of the liner along with the soundbar from the $500 wrecked '99 parts XJ I bought. I'm thinking the rear corner contour can me matched up with a little creativity. I'm thinking if you were to score around 2/3 of the way through the headliner from the back side, around every 1/2" or so, you could conform it to fit the curves. I'm gonna give it a shot anyways...

Yes, those are infact the same mirrors used on YJ full doors. I have two pairs laying around if anyone ever needs them. Totally freebies.

Right there w/ you TNT. Nothin like getting in the shop, firing up the welders and plasma and goin to town. Now if only I could quit blowin my money on everything else, and get my front 4-link fabbed up and bolted in!

As for the coil spring perches, look at the Ballistic Fabrication 4 in 1 spring, shock, track bar and control arm mount. They're $40 each, but you're getting everything all in one. Even if you didn't use the shock mount, as it is designed for a front axle, incorporating everything into one strong bracket wouldn't be a bad idea.

I too am sorry for the thread jack. I come from an off-roading forum where off-topic is all too popular. Anyways, I'm excited to see this go down. If it goes well, I may consider doing it...

The motor is still used in many applications. They range from as you said, bread vans, to small heavy equipment such as skid steers, and wood chippers. I have a friend who works on Volvo equipment, and he comes across them somewhat commonly. I just got an Isuzu 6cyl. diesel from him for free, with only 150 hours on it. Unfortunately people are realizing what they are worth, and they usually go for top dollar. If you have a tough time finding one, let me know, I'm sure I can help you out.

I've debated a diesel swap into my MJ project. I have an 86, so I'm still not sure if I'll be able to ditch the 2.5L and swap in a stroked out 4.0L as planned. I debated a small block Chevrolet, and even a Hemi. Here is what I can tell you about diesel swaps from my research: You'd never fit a 5.9 or newer Cummins in an MJ. For multiple reasons of course. Mainly the height of the motor. The massive oil pan would reduce clearance severely and also reak havoc on your suspension setup. The second primary reason being weight. The 6BT or 5.9 CTD is over 1000LBS, and you'd be looking at some serious sagging issues even with taller springs for compensation. There is however an MJ here in western PA, with a 4BT or 3.9 CTD in it. Around 200HP, 500ft/lb torque, and 30mpg. He's running that motor bolted up to an NV4500HD tranny, and around 6" of lift. Here's a picture: And a link to the diesel swap page, which also includes a full list of specs for the entire Jeep: http://www.4btswaps.com/forum/showthread.php?t=585

Sounds like you're talking about plugging a 220v welder into your dryer receptacle. What I did was buy a 5' dryer cord with bare wires on one end. I also bought a standard straight prong 220v box receptacle, and then wired the box accordingly. This will allow you to plug your 220v welder into any dryer plug receptacle.

Uhh...100% rust free for $300. No way in hell was I passing it up. I'll deal w/ fitment issues before i try and weld to rust!

I just built a set of rails for an XJ, and plan on modifying my design to fit my MJ. If noone comes up with a vendor to produce something that is a direct fit, and you guys like mine, let me know. I'd be up for making a bunch of them. Pix of the XJ set: Some of my other work:

Ah but there will be plenty of cutting, welding, and hammering! Damn '86 firewall!

After recently stripping the interior of my 2WD MJ, I noticed a cover plate over what looks to be a hole for a t-case shifter. Did all of the tubs, regardless of driveline have the hole cut for 4WD provisions, or was my MJ once a 4WD? Also, is there any type of VIN decoder for the MJ?

Not that it's much of a pricing difference, but there is a guy over on Pirate that is selling Clayton Off Road XJ front upgrade long arm kits for $800 shipped. Personally, I prefer the square tube over round for arms, it seems to hold up better. Could you possibly post a link or picture of the long arm chart you have?

I've not come across any more useful info on the 4.0L engine fitment issue. Anyone have anything? Anything at all???

My guess is Matt's ZJuggy that he broke again... Anyways, welcome to Comanche Club! Yeah, I was in on it. He seems to break the same spot over and over...Shear load from the first uca bolt snap absolutely weakened that upper mount. Anyways, I stopped by and welded it back together so he could get it off his trailer. The trailer I used to bring home my MJ...

If anyone knows about this...let me know. If it's true...let me know what I'd need to provide to figure out if my MJ is one of them.

Thanks for the info. Do you know of any threads that go into detail about the firewall trim? If it's a significant amount of cutting that might compromise the strength of the uni-body front half, I'd probably opt out. The only reason I'm asking is because I've got a 4.0L for next to nothing, that I planned on stroking out to 4.7L.