Eagle

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.

It's much easier than going the other way. You can get a shifter from any XJ (Cherokee). Keep in mind that different engine/tranny/transfer case combinations use different length control rods under the floor, so ideally you should get the parts from an XJ that has the same engine, tranny and transfer case as your MJ. The floor pan of your truck is already set up with the mounting points, just bolt the pieces in and go.

Yeah, but the towing instructions are based on the assumption that the front wheels will be off the ground (for a tow truck) or all four wheels will be on the ground (like for flat towing behind an RV). With the transfer case in neutral, aren't the front and rear axles locked, and just not connected to the transmission? I don;t think you *CAN* tow on a dolly with the transfer case in neutral. I don't think they fixed that on the XJ until 1994 or 1995. Better check before you rent the dolly. I would pull the rear driveshaft and cap the tail of the transfer case with a cut of soda bottle and hose clamp.

Has the speedometer been recalibrated for the larger tires? Did you re-gear when you put in the lift and big tires? Frankly, 15 MPG with 32" tires and a 5" lift is probably about as good as you have any right to expect.

A bored-out throttle body might help with performance, but it won't help with gas mileage. If anything, it'll make it worse. Read this thread: http://comancheclub.com/forums/viewtopic.php?t=9328 It starts off about exhaust pipe size, but it gets into the differences between the original 4.0L engine (which you have) and the HO. Too many owners of the non-HO version think they can make some magic, $5 tweak that will transform their engine into an HO version. Not gonna happen. The original 4.0L engine was not designed to run at high RPM, and was not designed to be a street drag champion. If your definition of "performance" is drag strip acceleration, you have the wrong vehicle and the wrong year. But ... 15 MPG is worse than your gas mileage should be. Is the truck all stock? 5-speed or automatic? What tire size? Does it have the stock gearing? Is that around-town mileage or highway mileage? How do you use it, and are you heavy on the throttle or easy on the throttle?

Running with a net instead of a solid tailgate helps, or a cap or a full bed cover

It should be an AX-5. It sounds like you may have a failing slave or master cylinder. First step would be to try bleeding the clutch hydraulic system.

Yes, but why would you want to? The original shift knobs for the BA 10/5 years are rubber, with a ceramic insert around a steel insert. The ceramic breaks, the rubber pulls off, and then you have to buy a whole new knob because there's no good way to repair them. (Believe me, I have tried.) I've swapped all mine over to the new style. Do it once and it's done.

If you're on stock tires that means you are cruising at 75 MPH. If you're on larger tires, it's even faster. 3.07 gear will NOT help your gas mileage, and may make it worse. The problem is you're driving a brick on wheels, and aerodynamic drag increases exponentially with speed. Back when I briefly owned a 99 WJ 4.7L, which had a more slippery shape than an MJ, I found that the gas mileage increased about 3+ MPG if I dropped the cruising speed from 70 to 60. I suspect the difference will be greater with an MJ. At 2300 RPM you're in the "fat" part of the torque curve. You won't gain much gas mileage by gearing to run well below the torque peak. That worked for AMC to beat the government economy tests, but those were run on a dyno, with no aerodynamic drag to factor in. That's why those mileage figures were pretty much invalid except as a comparison between different vehicles. They were useless as far as predicting what mileage you'd get in real world driving.

The tach wiring is all in place -- it's straight plug-n-play. You just have to be sure to get the right cluster for your year. You canNOT just add a tach to your cluster. The printed circuit on the back is different. You will need the complete cluster, even though you already have the other gauges. What it means, though, is that you would not need to replace your temperature and oil pressure senders.

4.88 3.73 with 31s is equivalent to stock 4.10 with 33s is barely better than stock IMHO, I view decent "all purpose" ratios to be 4.10s for 31" tires, 4.56 for 32" and 33" tires, and 4.88 for anything larger than 33" tires. The only reason I stop at 4.88 is that's the deepest ratio available for a Dana 30 front axle.