Geonovast

Yup, the only issue you'll have is with the transmission crossmember. The AX-15 one has a dip in the middle, which will most likely be a necessity, being as the trans is from a YJ, and will be clocking the T-case up.

I'm in for a bit when I get paid Friday.

If same motor and transmission, yes.

Click Lock the CAD link in my signature, there's some diagrams that explain this.

Really depends on your budget, how long the truck can be down, and how comfortable you are rebuilding your own motor.

I think that's the definition of having too much money.

The CPS has it's own plug, and connects on top of the intake next to the valve cover. If it fits, it's the correct one.

When it comes the 4.0, they should be. They should both be 3.07, but it's always a good idea to double check. The 2.5s had different axle ratios depending on if you had a 4 or a 5 speed.

No, it wouldn't. Your MJ is a Renix system being an 88, and the 91 is a HO(Chrysler). The electronics are completely different. Nothing between the clusters will swap. If you find a full cluster from another Renix, you can swap that one in.

Yes, you can use your existing rear end. You'll need to use the 91's transmission crossmember, as the AX-15's has a dip in the middle. Everything should be pretty much bolt in. You'll need to pull up the carpet a bit to install the body side t-case linkage bracket. There are dimples for the holes you need to drill, so you don't even need to measure anything for that. Make sure you check the size of the tip of the transmission input shaft before you go sticking the AX-15 in. The change was in 92, but plenty of the switches on these trucks overlap years unofficially. Being a 91, it should be the same size as your 88's, but make sure. Worst part about your conversion is needing to have your 2wd driveshaft cut down to the proper length. Make sure you use the 4wd yoke off the XJ's driveshaft. The hole for the 4wd shift lever is already there, with a plate bolted over it. The damn things were designed to be converted to 4wd.

He didn't specify year, Pete. He could very well have an AX-15. I'd still go with his advice though, chappy. Replace those bolts and do some sort of ritual sacrifice with them. If you take them to a scrap yard, ask if you can watch them burn.

Whoa Whoa. You said AX-5. That's a 2.5/2.8 trans. What motor do you have? Only the 4.0 has the torx bolts. The 2.5 will have an 18mm just like all the other trans bolts. Also, the 2.5 has 6 bolts that go through the housing into the block. 4.0 only has 4.

By a.10 do you mean 4.10? If so, yes, it should have a factory 4.10 geared rear axle. You're better off with it. If you swap it over to 3.55, 5th gear will become all but useless to you. To make the axle work, you'd need to cut off the XJ perches and shock mounts, and weld perches on in the MJ locations. For the speedo, you'd simply need to swap in the correct gear in the transmission.

I doubt it. If they ever existed, one of us would have at least found a picture of one by now.

You may or may not have room to get a socket onto a regular hex bolt though, that may be why they went with torx. I remember it being a tight fit. Or they used torx because that hate us, like they did with the top 4.0 bellhousing bolts.

I don't know what the books are smoking, but the 2.5's starter bolts are definitely the same, they're fairly long, and bolt vertically up into the block. I don't see how that could have ever been changed later on without modifications to the bellhousing, which I've never seen evidence of. Unfortunately I only have personal experience pulling the starter on one 2.5, a 91. :dunno:

A quick Googling brought me to a Jeepforum post, which states that it's a 4" long 3/8" bolt, didn't say thread count. Here's the two side by side.

Last time I pulled a 2.5's starter, they were identical, and freakishly long. Don, I think the ones you posted are for a 4.0. The 2.5's starter mounts to the block.

Cake for my 21st Maybe you could talk her into making the whole cake an MJ, and just getting bigger bride and groom?

I believe the AW-4 switched to 23 in 1990.

Indiana doesn't do it, and I believe Arizona doesn't as well. Must be really crappy for people that work/live in one of those places and then live/work across the border.

$^*& DST. It was practical back in the day, but in a world that functions 24/7, it's completely pointless. All it does is cause confusion, and problems, especially with people who actually have things to do when it happens. The lovely 9 hour work day for us 3rd shifters is not appreciated just because office monkeys like their pretty sunshine. It's outdated, and serves no purpose, it needs to go away.

That grill is hideous.

No splines to worry about on the front shaft. Bolts on on both ends, has a slip joint in the middle. You'll need one from an 87+ 2.5 with a manual. 84-86 used the NP207, and had a CV joint on the T-case end instead of the double cardan U-joint system. Spline count issues come up with mating a T-case to a transmission, which you'll not have to worry about if you buy them already together.

The only way to tell the difference between the AX-4 and AX-5 is to count the gears... externally they are identical. I'm a little confused about your front driveshaft question. Front shafts having nothing to do with XJ/MJ, it's all about engine/trans.