Eagle

Sounds like the clutch release bearing ("throw-out bearing") is gone. For an '88 4.0L, unfortunately that's all one assembly with the slave cylinder, so the part is pricey, but (subject to verification) I'd make that the first thing to have checked out. If you get confirmation that's the problem ... DO NOT give in to the temptation to save $$$ and buy the part from any after-market source. Replacing the release bearing on a 4x4 is not an easy or inexpensive job. You do NOT want to repeat in 6 months, and that's about the average lifespan for aftermarket clutch hydraulic system parts.

I don't know where you live, but opening the door was NOT a good idea. Yes, you armed yourself ... with a knife ... but the first rule of gunfighting is "Bring a gun." (Or "Don't bring a knife to a gunfight.") There have been several ARMED home invasions around here in recent weeks, and the invaders were armed with guns. If you had opened the door on a home invader rather than a drunken undergrad, he/they would have seen the knife and shot you on the spot. Do NOT open your door to unknown parties pounding on it at 3:00 a.m. Talk to them through the door if you wish (standing well to the side where they can't see you and hopefully can't shoot you through the door) or, better, just call the cops and tell them it sounds like someone is trying to break in your front door.

I bought a replacement gasket from the dealership a couple of years back, so losing the gasket is not my issue. I just couldn't figure out how to uninstall the window from an existing truck.

CPS. Yes, the TBI 4-cyl uses the same CPS as the 4.0L, and it causes the same problems when it goes bad.

Do you remove it from the inside or the outside? If this is something I can do at home, I have a pair of MJs waiting to have the sliding window moved from A to B, and vice versa. I even had a professional auto glass guy look at them, and he couldn't tell me how to do it.

Well, you guys made me go out and get dirty. It isn't often you whippersnappers get me doubting what I know I know, but my worthy opponent with his videos (which I can't see -- I'm on a dial-up) left me wondering. My '88 MJ doesn't have the original tranny or transfer case, so that would not have been a fair test. My '88 XJ, however, I bought new ... so I know it has the original tranny and the original transfer case. So I went out this afternoon, put the transfer case in neutral, put the transmission in first gear, jacked up the rear wheels and tried to turn them. Verified: The front and rear driveshafts ARE locked together. Further, this exercise reminded me that the ONLY way to get the transfer case from 2-Hi to Neutral is by first going to 4-Hi -- and that engages the front axle disconnect. This is why the owners manual says to tow it with the wheels off the ground, or else flat tow it with all four wheels ON the ground. Now -- why the discrepancy? I don't think Lead_Not_Follow is deliberately trying to mislead us. Since I can't view the videos, I don't know which of his three vehicles he used for the test ... nor do I know if any of his three is in factory configuration. But I do know that the XJ I just looked at is in factory configuration. In one of my initial posts in this thread, I said that I believe Chrysler changed the 231 so that Neutral does not lock the two driveshafts. I thought that happened around '93 or '94, but in thinking about it, it makes more sense that they would have done so in 1991 -- the year they stopped using the front axle disconnect. So my guess is that L_N_F was not looking at an '88 transfer case. But the guy asking the question has an '88. Which points up the fact that Jeeps are NOT all the same, not even within the relatively short span of the MJ, and it's never safe to generalize that what works for me MUST work for everyone. I stand by my opinion that you cannot tow an '88 on a dolly with the transfer case in Neutral. You could leave it in 2WD, but that would probably chew up some bearings. The safest course is still to remove the rear driveshaft and cap the transfer case tailshaft with a cut-off soda bottle.

Dunno if this is what you meant to write. Every OEM Cherokee/Comanche radiator I've seen had plastic tanks, and both replacements I bought had metal. The guy at the radiator shop said he can't work on the factory rads because he can't fix the plastc tanks where they meet the metal core.

If you have the MPFI computer and harness, I would update the 'Manche to the newer system. You'll get more power and better economy. Here's the deal: After Jeep introduced the MPFI 4.0L, a lot of people with the older, carbureted 4.2L engine in their YJ Wranglers were feeling left out. So Jeep came up with a kit to convert the carbed 4.2L Wranglers to MPFI. Basically, the kit is "just" the manifolds, injection, ignition, ECU, and engine room harness from a '94 Wranger. So ... if Jeep could split the system up to use just the engine controls to convert the older Wranglers, I see no reason why you can't swap in an engine that's already set up for it and just use the engine harness from the Wrangler in your MJ. Your speedo is mechanical and has NOTHING to do with the engine controls, so don't worry about it.

Correct

How much time before it goes loco? Initial guess --> oxygen sensor bad. Explanation: On a cold start, the engine by-passes most sensors and runs in "open loop mode," in which it pretty much ignores sensor inputs and uses a pre-programmed, slightly rich fuel map to run. Once the temp sensor sees that the engine is up to the operating range (around 180 degrees, minimum) it switches to "closed loop mode" operation, in which it reads the O2 sensor, temp sensor, MAP sensor, TPS, etc and controls the fuel mix and ignition timing accordingly. If it runs okay cold but goes wacky once it gets into closed loop mode, there's likely a bad sensor. The task then is to identify which one.

The '86 Command-Trac was the NP207, which was very similar to the NP231 but not as strong, and the low-range ratio was 2.6x instead of 2.7x. Low range 4WD is locked, 50/50 torque distribution. The 242 uses a differential to allow full-time use in 4WD. That means the torque distribution is variable, not constant.

No, your t-case is not broken, the problem is the Lead_Not_Follow is confusing a connection from the transmission to the transfer case with what we're really talking about. The Neutral position on the 231 transfer case disengages the transfer case from the transmission, so you can do whatever you want with the engine and tranny ... but it locks the front and rear driveshafts together. What various others have mentioned is that you can get away with towing that way because the front axle disconnect allows the front wheels to turn at different speeds. But the fact remains that both driveshafts will be spinning the whole way you tow, and if for some unforeseen reason there's a problem with the axle disconnect -- well, then there's a problem. It's so simple to just pull the driveshaft and clamp a cut-off soda bottle over it, I don't see why all the fuss to avoid doing it right.

How many miles are on the oxygen sensor? If it's old, it doesn't react as fast as it should to throttle changes, so if you're running rich to accelerate and then take your foot off the peddle, it still sends a rich mix to the engine but the engine doesn't need it -- so it dumps some unbruned gas down the exhaust and it backfires when that hits the catalytic converter. I'll bet your gas mileage is sub-standard, too. Replacing that O2 sensor should fix the backfire and improve the gas mileage.

The older ones can be reset. The factory didn't design them that way, but innovative (i.e. redneck) engineering has prevailed, and enterprising (cheap) young men figured out how to reset them. The write-ups are out there if you look. Basically, it goes off about every 75,000 miles as a reminder to replace the oxygen sensor. Unplug it and just write down when your O2 sensor is due for replacement.

My guess is ... very hard. Are you an automotive or structural engineer? The front of an MJ is unibody. Are you qualified to analyze the strength of what you would be cutting off and to design an entire new frame to replace it? I'm a licensed architect with post-graduate work in structural engineering, and I wouldn't touch that on a bet.

Tilt columns are over-rated. I have yet to see one that wasn't most comfortable in the straight position, for everyone from about 5'-6" to well over 6' tall.

Man, what part of "Four-wheel-drive vehicles should be towed on a flatbed or with the wheels supported by a dolly." do you not understand? You're the one who's quoting it, but you're trying to make it say something other than what it says. It means ALL FOUR WHEELS OFF THE PAVEMENT. Why do you think tow trucks carry around those little dolly things they stick under the trear wheels when they pick up a 4WD vehicle? The section of the book you're referencing is NOT talking about the dollies you rent from U-Haul.

Actually, there are three kinds of speedos. Two of them use cables, and the attachment of the cable to the speedo head is different. One (the early type) uses a metal clip to hold the cable to the speedo. The later type uses a white nylon clamp. Unfortunately, 1987 was the "swing" year, and I believe the change may have been made mid-year in 1987, so you need to look at YOUR speedometer to determine which type of cable attachment you have.

I still don't understand why you want to take the shifter apart just to replace the boot. Sorry, I guess I'm having as slow week, but I'm just not seeing what your problem is.

Yeah? The underlined entry immediately above that section of the manual says it applies to recreational towing. That means towing behind an RV with all four wheels on the road and turning. The question in this thread doesn't involve recreational towing. What's your point?

No, I do not understand what you're trying to do. You want to take apart something that isn't really meant to take apart. What's the reason, and why can't you use a replacement shifter out of a junkyard if yours is broken? I can't help you with solid advice if you're going to be a smart-@$$.

That's pretty much what I remember ... If you read those owner's manual entries carefully, none of the conditions described covers front wheels on a dolly and rear wheels on the road. When the owner's manual talks about towing 4-wheel drive vehicles on dollies, they are referring to front wheels on the hook and off the ground, and REAR wheels on dollies so the front wheels aren't spinning while you're towing.

What are you trying to do? According to the FSM there is a special puller needed to do that. I asked my friends at the dealership if I could borrow theirs, and they said they tossed it years ago because all it did was break the shifter and then the shop had to buy a complete new assembly. Unless yours is already broken, I respectfully suggest that you not mess with it.

Longbed or shortbed? JC Whitney used to sell replacement sides for the MJ box. I don't know if they still do.

Keep in mind that the key part in the steering column is just the key part. The actual ignition *SWITCH* is located at the base of the steering column. There's an operating rod connecting the key to the switch. Your problem could be in the key cylinder, the operating rod, or the switch itself. Or it could be the CPS, but that would not cause the starter to not function.