Eagle

Probably anything is "traditional" somewhere. I grew up knowing about New England clam chowder and Manhattan clam chowder. The first time I was served Rhode Island clam chowder in a restaurant I thought I'd been cheated. Now I prefer it over the other two. Didja know in Rhode Island they eat French fries with vinegar, not ketchup? Yyyuucchh!

I would not do the head gasket. I WOULD do the rear main seal, because it's SOOOO much easier with the engine out and upside-down on a stand than when you're lying on your back under the truck. Once the pan is off to do the rear main seal, it sort of doesn't make sense not to replace the bearings. I wouldn't even bother to plasti-gage them ... just do a preemptive strike.

Your speedometer may be off a little. With 31" tires and 4.56 gears, 75 MPH should be 2906 RPM. I guess that's "about" 3000 RPM, but it's lower than, not higher than. Secondly, for a 1991 the torque peak of the engine is around 4,000 RPM. 3,000 RPM cruise is below the torque peak. That RPM isn't going to harm the engine. You have to remember that the 4.0L engine is an evolution of AMC's older 232 (3.8L) engine that came out in 1964. Back then, nobody had overdrive, and most cars were still manual transmission with "three on the tree." My family owned a number of AMCs from that vintage. They were typically geared with 3.08 axles and small-ish tires, such that the speed to RPM came out to 24 MPH per 1000 RPM. 3000 RPM produced a 72 MPH cruise speed. They ran forever like that. The one we tracked the longest was a 1970 Gremlin that my brother and his wife rallied, autocrossed, and used as a daily driver for four years. When they bought a new '74 Gremlin, he sold it to a local auto parts store to use as a parts delivery runner. Last he heard, it had gone over 375,000 miles and they never had the head off it. My view is that 4.10 gears are the optimum for 31" tires, but if I bought one with 4.56s I certainly would NOT spend the money to change to 4.10s. There would be very little to gain for the expense and trouble. Your 75 MPH cruise would drop to 2614 RPM.

How high and how long?

'86 thru '90 had TBI, '91 and '92 had MPFI. The 4-cylinder was carbureted in the '84 and '85 XJ, never in the MJ.

Does NOT sound like fun, but get it fixed and get well soon.

I didn't say they are the only safe hooks. It is absolutely unsafe to bolt hooks directly to the unibody -- reinforced mounting brackets are a must. I think the C4x4 kit is the best. The one you linked to also looks decent but I haven't seen it "up close and personal." There are others out there, as well -- including (last I knew) as individual parts from Keystone (the Chinese fender vendor). Take your pick -- just DON'T bolt tow hooks (or D-rings) directly to the unibody.

:agree: OBD-XYZ is here to stay. The scanners that Harbor Freight now sells for $29 or $39 are infinitely better than the brain-dead unit they sold for $49 (on sale) just three or four years ago. But ... don't buy the cheapest one they have. Spend a few extra $$$ and get one of the ones with CAN [something], so you'll have more flexibility to use it on newer cars -- whether your own, your family's, or your friends'.

You have the right idea, but using tire circumference isn't very accurate. Most of the tire manufacturers include in their specs a figure for revolutions per mile, which takes into account the amount of sidewall flex under a normal load as well as tread squirm. In making up my spreadsheet for comparing gear ratios and tire sizes, I used manufacturers' revolutions per mile for the calculations. Even within one (nominal) tire size there's variation between/among brands. In fact, at one Time Cooper had a P235/75R15 and the same tire as a 235/75R15 LT. The LT had stiffer sidewalls and, even though ALL dimensions of the two tires were identical, the revs per mile were different. Back to the bottom line. In round numbers, going from a stock 215/75R15 to a 30x9.50 is a difference of approximately 6%. Going from the same 215 to a 31x10.50R15 the difference is 11%. If you start with a 225/75, the difference will be slightly less. In VERY round numbers, and for most practical purposes, I think it's valid to generalize and say that going from "stock" to 30s is about a 5% change, and going from "stock" to 31s is about a 10% change. If you're running 31s and the gas mileage calculated from the odometer is only 12 MPG, then correcting by adding 10% only brings it up to 13.2 MPG. That's not very good for a 4.0L MJ.

Thanks for the tip. The driver's door speaker in my wife's 2K XJ is out and I was planning to dig into it while she's visiting her kids.

Oxygen sensor. And I seriously doubt that anyone gets close to 30 MPG out of a 4.0L MJ. The very best my '88 XJ ever did was one tank on one trip when it was almost new, when I got 28 MPG. More typical is 18 around town to 21 or maybe 22 highway -- and I drive like an old lady. The '88 MJ typically runs a couple of MPG less than the XJ, probably because the aerodynamics are worse; the MJ runs around 17 to 18 in local driving, and 18 to 19 MPG highway.

That's the problem. I have no idea why, but it's well known that aftermarket clutch hydraulic parts rarely go more than 6 months, whereas OEM Jeep parts go for decades. My guess is the aftermarket stuff is remanufactured, and the tolerances are not held close enough. (But that's just a guess.)

If the MJ is the same as the XJ, the factory rear spring bolts are 14mm. That's approximately .552". In a pinch, I have used 9/16" bolts in XJ rear springs ... those are .5625". The Grand Waggy is a derivative of the old full-size Cherokee, so I'd bet that the springs and bushings were not sized for metric hardware. Use 9/16" bolts and see if that helps.

Did you buy a genuine Jeep slave cylinder, or aftermarket?

The old factory radios were fine as FM receivers, it was only the tape function that had a tendency to go AWOL. If you're just looking for FM tunes, go for it. Besides, you can always get one of those external CD adapter things that "broadcasts" to an FM station on your radio.

"They" above referred to XJs with the wood grain dash bezel. That trim also came on the early XJ Wagoneers. I had a 1984 that came with that trim. This truck is too nice to modify.

:agree: The MJ is a uni-body. You can't just bolt on hooks, you MUST add mounts of sufficient strength to stand up to the forces applied. The C4x4 kit has brackets that are near-clones of the factory mounts.

Looks pretty good to me. As noted above, it appears some dash trim was swapped in from an up-model Cherokee. The front grille and bumper look original to me. The rims and the rear bumper are aftermarket. The shift knob is aftermarket, and so are the cup holders on the center console.

Keeping it original is a noble goal and I support it 110 percent. However ... this is one place where doing so is to shoot yourself in the foot. The factory tape player was a horrible piece of junk and they mostly all failed within a very few years. The chances of finding one that works are probably in the single digits. If you do find one, use it a few times and you'll be right back to an AM/FM radio. For a trucj you intend to drive, I recommend an aftermarket head with a CD player. If you're restoring it for show, then keep the radio you have.

No MJs (or XJs) came stock with 235s. Early MJs and XJs came from the factory with tires ranging from 195/75-15 to 215/75-15, depending on model. Later the factory increased the tire size, but the largest they ever offered on the MJ was 225/75-15, and on the XJ either 225/75-15 or 225/70-16.

My brother and I have moved one around. I doubt very much that it weighs 495 pouns ... that would be 250 pounds for each of us, and I don't think I'm strong enough to think of 250 pounds as "not heavy." BTW -- It's "short," not "shot." When I saw the thread title, I could NOT figure out what a shot box is and where it might be found on a Comanche.

There should be no adapters necessary. Except where the hard ;ines come out of the metering block ("combination valve" ... but it isn't on an MJ) below the master cylinder.

Replace the right front turn signal socket. The ground id bad and it's backfeeding through the instrument cluster.

Nope. Not due to the high volume pump ... but I'm certain that doesn't help. I was first clued into this problem by a fellow XJ owner down-state from whom I bought a set of OEM alloy rims about ten years ago. He had the problem, and he said it drove him nuts for about three months. Once he noticed the collapsed lower hose, he scrounged a spring from a garage's pile of scrap radiator hoses, stuck it into his hose, and all was good.

My wife is interested in trying to initiate a small (very) sales operation, Internet based. Rather than offer one item at a time through e-Prey, we would like to grab a domain name and set up our (her) own e-commerce site. The problem is, I lost track of how to work on computers once we progressed beyond MS-DOS. What's the easiest and cheapest way to create a small e-commerce operation? (I know that "easiest" and "cheapest" may be mutually exclusive. If that's the case, what's easy, and then what's cheap?) TIA