Eagle

Ahhhh, there in-lies a problem. I don't have any of the MJ axle stuff. What do you mean you don't have any of the MJ axle stuff? Isn't there an axle under your truck now? If so, you have the "stuff." The XJ rear axle is set up different from the MJ. Aside from the XJ having the springs over the axle, on the XJ the lower shock absorber mounts are brackets welded to the axle tubes. On the MJ, the lower ends of the shocks mount to pins on the spring plates. When using an XJ axle, you either cut the shock brackets off and throw them away -- or you could just leave them, if you won;t be doing heavy off-road stuff. You could cut the XJ spring pads (perches) off and re-use them. Or you could buy new ones. The best deal going for spring perches, if you buy new, is the pair from the Mopar Performance Catalog. They are beefy, slightly longer than the stock ones, and less than half the price of anybody else's. If they are still available, the part number is P4120074

We obviously have a failure to communicate. Chrysler introduced the HO (High Output) version of the 4.0L engine in the 1991 model year. That's the year the heads, manifolds, and ports all changed. Considering that 2001 was the LAST year of the XJ, I'm not sure what you had in mind by calling an 01 or older "pre HO." Your engine is a Renix 4.0L. It was used from 1987 through 1990 in the Cherokee and Comanche only. That's ideally what you should be looking for. You could get an HO engine and put your head on it ... but that presupposes that your valves, guides and seals are all in good shape.

I don't think it looks at all like an MJ. But then, a Cheromanche doesn't look like an MJ, either. This thing, in fact, looks a lot more like an Isuzu Amigo on steroids than it does like an MJ. I think it looks good and it appears to have been VERY well done, but it doesn't look remotely like an MJ, or even like a "pickup truck." Why waste an MJ tailgate on it?

You don't measure oil consumption by time, you measure it by miles. How many miles did you drive in that time, and at what speeds?

:agree: That seems to sum it up pretty well.

I like it, but I wouldn't compare it to a Comanche. It's really the ZJ version of the Cheromanche. So I guess it would have to be called a Grand Cheromanche.

The block is essentially the same but the ports on the HO heads are shaped differently and raised up higher. Some people have managed to modify either the HO head or the Renix manifold to be able to bolt them together, but due to the mismatch of the port shapes it's just not a good idea unless you have no choice. Also, the Renix has a temperature sensor down low on the left (driver's) side of the block for providing temp data to the ECU. The HO engines use a sensor in the thermostat housing to send data to the ECU.

Back to the transfer case - the 231 is slightly stronger than the 242, but ... try to find anyone who has busted a 242.

All XJ axles need to have the perches relocated. XJs had the springs over the axle, MJs had the springs under the axle. Also, the center-to-center distance is different for the XJ, so even if you were doing a spring-over-axle conversion using an XJ axle you would have to move the perches. The ONLY direct bolt-in axle for an MJ is from another MJ.

It looks just like the standard cluster -- except the speedometer goes to 120 MPH (or is it 140?) instead of 85

Your '87 has the Renix injection/ignition system. Direct replacements will be 1987 thru 1990 Cherokee or Comanche. Chrysler changed to their own injection/ignition system in 1991.

The front skid plate and the tow hooks will fit your XJ or your MJ. The gas tank skid for the early XJs with the steel tanks is very different from the skid for your 01 with the plastic tank. No fit. If it has those skids, does it also have the transfer case skid? It's probably worth going back for. You can always sell the gas tank skid on NAXJA.

Finding a D44 from a Comanche will be difficult. If you are fortunate enough to find one from a Cherokee, you will still have to relocate the spring perches. Don't overlook the Chrysler 8-1/4 axles out of Cherokees. The later model ones (1997 thru 2001) are 29-spline axles that are very nearly as strong as a Dana 44, and they are the correct width for a Comanche. With a Ford 8.8, you have to run either aftermarket rims or spacers.

WANT!

They are Command-Trac, not Selec-Trac. NP 231 stands for New Process 231, where New Process is the maker. In some years it's NV, for New Venture Gear. Same company, different name on the door. 231 J is an NP (or NV) 231 case made for a Jeep vehicle. Selec-Trac was a 228/229 for 1986, and a 242 from '87 thru '92.

Yeah, or he was a doofus and only replaced the main bearings. If you run 20W50 oil, does the knock go away when the engine speed is over about 1500 RPM? If the vehicle has gauges, what kind of oil pressure does the gauge think you have, at idle and at 1500 or 2000 RPM?

Why? My '88 XJ has 287,000 miles on the clock and doesn't knock. It is very common to just throw new bearings into a 4.0L engine to resolve oil pressure issues. They rarely need the crank turned, unless the owner waited much too long before deciding to do the bearings.

The best way is not the easiest way, nor is it the least expensive way. There must be a couple of hundred threads on just this forum discussing various ways to lift a Comanche. I suggest you do some reading first, then decide what questions you have that our members haven't already answered, and ask your questions. Be specific. The question you asked is impossible to answer.

Nyuk, nyuk. Reminds me of a story: A businessman was at a conference in another city, and after hours he was hanging out in the hotel bar when he spotted a REALLY hot chick. He went over, bought her a drink, and then he asked her if she would sleep with him for $100,000. "Sure," she replied. "How about for $10?" he asked. The woman became visibly angry. "What do you think I am, a common lady of the night?" she asked. "We've already established that," said the man. "Now we're just negotiating the price." HOW COULD YOU SELL AN MJ?

Clayton's used to offer a kit for mounting the FSJ axles in XJs and MJs. Don't know if he still does, but it was a top drawer product.

If it's an automatic, a cracked flex plate can make a knocking sound that's similar to a bad bearing. The test is to run it at idle. If it knocks in neutral, but it in gear with the brakes on and step on the bas just a little. If the knock disappears, there's a high probability of a cracked flex plate.

Dunno. You're the one in Rhode Island, we should be asking you that question. Rhode Island must be about the only state in the country with that rule. I knew that, once, but I had forgotten.

I've been wrong before, but ... if the AW-4 was the only automatic used behind the 2.5L after 1986, why are they so hard to find? That would suggest that ANY 4-cylinder XJ with an automatic from 1987 right up through 2000 should have an AW-4. But cruise the junkyards. How may are there? They virtually don't exist. I guess they made some ... Jeff tells me he has one ... but they are even more rare than the proverbial XJ Dana 44.

The "full width" axles on the FS Cherokees were actually an option -- it was the "wide wheel" option, available only on the 2-door Cherokees. 4-door Cherokees, Wagoneers, and all Grand Wagoneers got the standard width. The difference isn't all that much. Back in the day, my brother had a '78 with the wide wheel option and I bought a used 4-door that didn't have it. My front fenders were totally history and I found I could get replacements with the flares for the pickup and wide wheel for the same price as the standard fenders, so I did. With 31" tires on, if mine was parked next to my brother's you really had to look to see the difference. It was maybe an inch on each side?

Depending on the backspacing of the wheels, you might need a 2" spacer in the rear to keep the inside sidewall from rubbing on the inner wheelwell. I question the wisdom of running 16" rims at all. With Ford rims, the center hole probably isn't correct for Jeep axles. If it's too small you have to grind it out, and if it's too large you lose the stability and support derived from Jeep's "hub centric" wheel design. Plus, for any comparable size, 16" tires are more expensive and harder to find than 15". Your frames of reference: Stock Jeep rimes are (mostly) 15" with 5-1/4" of backspacing. On those rims, both front and rear will accept 31x10.50-15 tires and require NO trimming of sheet metal or flares. The fronts rub on the lower control arms (slightly) at full steering lock, which is only a minor annoyance. In the rear, the inner sidewalls are very close to both the springs and the inner fenders. When I wheeled my '88 MJ with 31s on factory rims, after every trail ride there were black rubber marks inside the wheel wells where the top shoulders of the tires rubbed the fenders if the axle got "articulated." That's for a 10-1/2" tire. A 12-1/2" tire extends 1" farther out, and 1" farther in. You could NOT run 12-1/2" tires in the rear on stock rims without a spacer at least 1" thick, and preferable 1-1/2 to 2 inches thick. A quality spacer machined from billet (not a cheap casting) would be fine -- but pricey. Wheels with significantly less backspacing would also solve the problem -- in the back. But ... if they are out far enough not to run the inner fenders ... they won't clear the flares and outer sheet metal. But in the front, any tire wider than a 10-1/2" OR on a rim with less backspacing than factory will NOT tuck up inside the sheet metal. So once you either use aftermarket rims or go to tires larger than 10-1/2" wide, you either have to trim, or you need massive lift just to clear the sheet metal at rest. Worse, you also need to severely limit the amount the suspension can compress, because lift by itself doesn't stop the axle from moving up and sending the tire crashing into the fenders. You need to extend the bump stops -- the less you want to trim, the MORE you have to limit the suspension travel. That gets you on the street with sexy-looking big rubber, but it doesn't do squat for you on a trail. Too many people, IMHO, decide that they NEED huge tires without giving any thought to how they plan to use the vehicle or what it takes to actually run those tires. The goal should always be to engineer the vehicle to run the smallest tire and the LEAST amount of lift necessary to accomplish your requirements. The cost of tires increases significantly with size. The cost of lifts increases exponentially with height (in other words, expect a 4" lift to cost four times as much as a 2" budget boost, not twice as much).