86 Grand Wagoneer 4.0 swap

[carhartted]

I picked up an 86 wagoneer with a seized engine. My plan was to put it on a 1st gen cummins frame and run a 6bt. Unfortunately I've had to use all my Cummins parts to keep my other trucks running. So I just got a smashed up 93 Grand Cherokee. What needs to happen in order to put the 4.0 into the Wagoneer? Would it be best to use the Cherokee trans and transfer case or stick with the Wagoneer unit? I'd like to see stay away from driveline work if possible, it's quite expensive around here.

Thanks

[backroadin']

If the front diff drop is the same between the rigs, you can bolt the 4.0 right to your existing tranny. Otherwise, a complete driveline swap would save you from buying adapter plates. I'm assuming the waggy has a 360 in it now? If so, I think you might need the I-6 frame horns. I'm not sure if you'll need to move the tranny crossmember back a bit or not - if so you'll need shorter rear driveshaft, and might be able to use the front one off the 93. Good thing you have the whole parts rig - you'll need a bunch of little stuff here and there. I put a 4.0 block in my 73, and I used an 89 parts rig - but it was years ago so my memory is a little foggy. I think I had to use the older 258 style engine mount brackets and FSJ/CJ style motor mounts - the bosses for the older brackets should still be there on the 4.0 even though I think they only use two of the three you'll need for the older style mounts. (xj mounts are a totally different style). On the 89, one of the bossed was used for a knock sensor so I had to use a larger metric fine thread nut for that hole in the bracket - but I seem to think the 91-up didn't have a knock sensor there.
The 4.0 has no provision for a mechanical fuel pump so you'll need an inline one if you want to be carbed. Otherwise you'll need to have a high pressure fuel pump. I'm guessing you're fairly handy with a wrench so you probably already know all of that stuff.
If the 93 has a CPS and you want to keep in FI, it might be easier to keep the whole 93 drivetrain, but I don't know much about all the computer stuff. But the 4.0 will definetely bolt right up to your 86 tranny, which I assume is an auto. If stick, you'll probably need a different pilot bushing.

What's the 86 drivetrain, and what's the 93 drivetrain?

If your 86 for some reason is a 258, then the whole deal will almost be bolt in. There's alot of guys here that know more than me on all this stuff so hopefully they chime in.

[backroadin']

By the way - welcome to the forum!!

[carhartted]

Thanks. The project has been in the works for a while. The 86 has a 360 and the 93 has a 4.0. I can handle the nuts and bolts part of the swap. I just don't want to reinvent the wheel when it comes to the different parts I'll need.

I plan on keeping the fuel injection. Between the cps and the overdrive I'll try and run the complete drivetrain from the 93.

[wiley-moeracing]

You should be able to do it with little problems since you have the complete donor vehicle. will have to modify the drive shafts and shifters but that's about it.

[tgreese]

Position of the transmission and transfer case will have to change with the 4.0L. The 258 six was used in these Jeeps, and frame towers (motor mounts) and those motor mounts could be used to replace the V8 ones. replacement of a 258 with a 4.0L is almost a drop in, but it's more complicated with going from six to V8 or vice-versa. The six is longer and the front of the two engines sit in the same place. The core supports are different and the six has a narrower radiator with different outlet placement. Aside from plumbing and wiring, change in the trans/TC position and driveshaft length is the main difference. Likely you can buy a flex plate for the 258 and it will work - the sixes are neutral balance and the V8s are not, so not compatible. Brake booster interferes with the 4.0L intake IIRC, so hydroboost or a smaller booster may be needed.

This is a ZJ Grand Cherokee? IIRC these 4.0L have different mounts from the 258. I don't know the details, but I think that its discussed on the jeepstrokers forum. You may have to fab your own mounts, and the accessories may not align well. Maybe - worth researching before you start.

[carhartted]

It's a ZJ, I'll take a close look at the motor mounts. I have a core engine from what I was told was an XJ, with motor mounts. Thankfully I have the entire rig so I can use the ZJ radiator to help line things up better.

I've done a couple hydraboost setups so that should not be a problem either.

I'll plan on using the ZJ transmission to make mating the 4.0 a non issue. Sounds like motor mounts will be the big question. I'll know more when I get the ZJ apart.

Thanks for the replies.