gogmorgo

There were three factory skid plates on the MJ. One that protects the front axle and front of the engine bay, one for the t-case, and one for the fuel tank. The front and t-case skids should swap from a junkyard XJ, but the tank skid is unique to the MJ.

Yeah, it does something like that. I was never really sure whether it skipped a bit or just started at 250.

Correct me if I'm mistaken, but wouldn't the ECU be informed by the TPS when you back off the throttle? You'd get a much faster result than waiting for even a good O2 sensor to catch up, and it's what happens when you open up the throttle.

An unbalanced brake drum would cause vibration all the time, like an unbalanced wheel or tire, would it not?

It would also depend on the recovery. If you dropped one wheel into a hole and just don't have enough traction at the others to get you out, it likely will work. But if you sink both axles to the floorboards, you'll soon be wanting for a better tow point.

But now I'm kinda wondering who it is, and what other goodies they might be willing to part with... At less obscene prices, of course.

I was saying you should put it in the heater feed line instead of the heater return line. You'll loose some heat going through the heater core whether or not you have the heater on, so you'll get better performance if you put it in upstream of the heater.

Well, it'll work without the heater on. Beyond that, though, I can't say how well it'll work. If you do put it there, try to get it in the line to the heater. That way it won't be affected by any coolant temperature loss through the heater.

Nope, totally not this guy. If I had some NOS taillights in my possession, I can assure you they'd stay that way! Also, I'm not quite so fiscally savvy as that... ;)

With the stock heater flow valve in place, you have no flow through the heater lines and your fan(s) wouldn't come on without the heater on. It could also trigger with the tstat closed, preventing your motor from reaching operating temp.

The factory bumper hitch is rated to tow all of 1000 lbs. So I'll say no to recovering with it. See if you can get a proper hitch built for it?

A wild fire is never under control until it's completely extinguished. I work in a national park in the summers, and they do "prescribed burns" there... basically they take the areas most at risk and deliberately burn them in a "controlled" manner before they catch fire on their own. Very rarely do they get hugely out of hand, but I've yet to hear of them managing not to burn a few extra square miles beyond what they intended.

I did the same to a '93 Taurus a couple years back. Only two blades were needed and one 4.5" cutoff wheel in an angle grinder. The cutoff wheel is for anything the sawz-all bogged on.

You paid $800 for it? I guess that's what it's worth then. What it comes down to is really how much someone's willing to pay. This depends a lot on where you are... an only slightly rusty truck could take top dollar up north, but be worthless down south.

A stroked 4.0 when done properly, is just as reliable as stock. Just ask Hornbrod. I'd wager that most of the stories you've read are from people who assembled their own from junkyard parts. The concept is mostly just an AMC 258 crank in a 4.0.

Actually, the Torsen is fairly simple in principle. They're set up the same way as a typical open differential, only they use helical gears against a worm instead of the traditional spider gears. This ends up working like a worm drive in that you can spin the screw part and it'll turn the worm gear, but you can't spin the screw by turning the gear. Because of the helical cut of the gears in a Torsen, you do get some "backwards" movement, which is what allows it to function as an open diff, but you can't get huge differential wheel speeds because the gears will bind. It also doesn't lock, ever. It's only a limited slip, and the amount of power it can send to the wheel with more traction is a function of the amount of resistance (i.e. traction) at the other wheel. That means that if you lose traction completely, say by picking up a wheel, it can't send much power to the other side... but a gentle application of the brakes will fix that. There's a lot of info out there on how they work, and a lot of it is pretty well engineering reports explaining all the minor details of this and that, and the rather beautifully simple bigger picture of how the unit does its thing tends to get lost in all the focus on torque bias ratios and preload and other mumbo-jumbo.

Now get this: the MJ's switch is a direct replacement for the '64 to '66 Plymouth Valiant and 'Cuda...

My '91 long bed's bumper brackets have the buldge for the shackle hangers. My hitch brackets had to accomodate that, but I was just going to use 1/4" spacers. Shoot. I knew that... :doh: Haven't done any CAD since August. The reason I didn't include the part file was because... weeeeelllll... I'm not sure I have it. This was over a year ago, so I'm a little foggy on the details, but I was doing stuff on the computer in my FSAE team's shop, and hurriedly jumbled things onto a flash drive, which I've since misplaced. Somehow, though, I wound up with a "hitch" folder on my cabinet on the university's server. The folder has five files. The first two are a log and crw from a study, so I'm guessing it was the FEA stuff I was doing. The next file is the drawing file, called revision 2, and the other two are parts files... one's called revision 1 and the other's named as if it were the original. But here they are: "Original" (part) "1st revision" (part) "2nd revision" (drawing, same as above but included to keep things together) Hopefully one of the two part files is linked to the drawing... It just occurred to me that these could have been from someone else saving everything I left open when I left the shop, in which case I have no idea what they actually might be. My student license for SolidWorks 2013 expired in December, so I'd have to go back to the unviersity to open the files to find out what they are, and that would likely involve, er, "creatively entering" the shop because the computer labs only have SW2007 ilast I checked.

http://www.filedropper.com/sideplateforexpedition2ndrevision Here's a Solidworks drawing file I put together a few years back. I'd intended to use it with a hitch I pulled off a Ford Expedition, but I never got around to finishing it. I didn't even get all that far into mockup, either. I think the bolt spacing is accurate for using all four of the bumper bracket bolts on the side of the frame, however I'm not positive on that. I went through a couple iterations with the bolt spacing, and I for some reason I have an inkling suspicion the final version somehow didn't make it to the drive where I saved them, so definitely check that before your order is carved in steel. Another thing about that particular end plate is that the factory hitch's crossbar mounts behind the bumper, and the receiver drops below the bar and bumper, so only the receiver tube is visible. The Expedition's hitch, on the other hand, has the receiver tube mounted at the same height as the crossbar, so the crossbar also ends up sitting below the bumper. Some people may not want that, as it leaves something else hanging under the bumper, although I was thinking it would be good to have a little extra there in case the bumper gets slammed against the ground, and if I wanted to I could always add recovery shackles to it and still keep the factory bumper. Unfortunately, I don't have the resources at hand to do much with that file. If you can't open a SolidWorks 2013 file, you may be out of luck. For reference, (although you've likely already seen it) this is a pdf of the bracket from earlier in this thread, with three holes plus one for the shortbed shackle mount bolt. I did some quick FEA on the bracket, and IIRC I concluded that the shackle bolt provided better reinforcement to the bracket than adding a hole for the forward-most bumper bracket bolt. But any CAD or CNC guy worth their salt should be able to make something with the PDF drawing. We have a laser cutter at my university that actually "prints" PDF files, although you need to set them up carefully so that the line thicknesses are correct to the laser's beam width. https://docs.google.com/file/d/0BzTWL2t-sbKdNkRCQ056QUJZMVk/edit?pli=1 The difference between the rear section of the frame where the bumper and hitch bolts up is that the short bed models have the rear spring shackle mount right under the bolts. The brackets have a bulge to accommodate the mount, and the same brackets were used in both long and short beds. (At least in later years). The hitch used the same end plates for both bed lengths as well, but with spacers on the bolts so that the flat plate didn't need to accommodate the bulge. However, there's a chance the '86 model year brackets could be oddballs. There was no short bed for the Comanche's first year, and it can't be guaranteed that AMC initially designed the bumper brackets with the short beds in mind. In the event that they had to change the brackets, it's also possible that they changed the brackets but without changing the part number (or the part numbers got fudged a bit when ChryCo took over). I've never seen factory bumper brackets on an '86, though, so that's all conjecture. If my theory is correct, it also wouldn't surprise me if even after the redesign, some long beds got the early version of the brackets while they used up any remaining inventory, so there's a chance some '87 long beds may have oddball brackets as well. Mostly that last paragraph is a possible explanation as to why your hitch doesn't fit properly. You could always notch the hitch's brackets to fit around the shackle mounts (I'm assuming that's the problem) or else put spacers between the bolts to clear everything properly. You'd also need spacers where the brackets bolt to your hitch's crossbar, and would either have to adjust the holes in the brackets for the bottom of the frame or just leave the bottom bolts out. I'll add that I really have no idea what your hitch brackets look like, only a foggy picture in my head based on your description, so don't immediately dismiss me as an idiot (although I won't deny that it may be the case). Also, the extra half-inch you're seeing in the short bed bracket is likely because of the presence of the spacers, which add a quarter-inch on both sides. After taking this all in (or not... it's a lot of words), keep in mind that Jeep Driver is correct. The process for a hitch shop to build you a custom hitch is going to be something like: 1. Look for place to mount brackets to vehicle. 2. Position receiver in desired location 3. Attach the receiver to a cross bar that's wide enough to reach the mounting points. 4. Take a steel plate (which will be 3/16" or 1/4", depending on needs) and cut, drill, bend, weld, etc so it joins the crossbar to the mounting brackets. Many shops may drill extra holes in the frame instead of using existing holes. There was one custom job a member on here posted up that only bolted to the bottom of the frame. There are 1000 ways to do it, and just about all of them will work. It's also true that in the amount of time I've put in thinking about this, I could have easily reproduced the factory hitch as it's represented in this thread. My craftsmanship is nowhere near the level of Jeep Driver's, which is in part why I never got around to finishing my hitch, as I'm not confident what I build won't fail in a catastrophic way, even though I know the design is sound. It also wouldn't surprise me if a dollar amount were put on the time I've spent thinking about the hitch, it would double or triple what a shop would charge for a custom job.

5/16" is bigger than 1/4", no? I was in the middle of writing a post this morning with a link to some stuff that may (or may not) be helpful, but got called in to work early. I'll finish it up when I get home.

You can buy a cheap engine hoist for likely less than a shop will charge you to put in a motor, even if you're doing the rest of the job yourself. Princess auto has a "Quick Lift Shop Crane" on sale until Sunday for $220. I'm in the same boat as you right now. About a year ago, mine started doing the death knock after coming down from 185km.h. Just over 498,000 km on it. It still runs and drives (drove it onto and off the dolly that brought it home) but with it turning its innards into glitter, it's sitting under a snow drift in my parents' yard. With school, I haven't been able to put much money towards the project yet. Hopefully something happens this summer. :crossfingers:

Short answer? It's cheap and easy. The 4.0 was a new motor. It needed a new intake, fuel system, etc. to go with it. The 2.5 on the other hand had already been in production for several years. Emissions and economy requirements meant that the set-it-once-and-forget carburetor needed to be replaced with a self-tuning system. If they had gone to mpfi, in addition to a new throttle body, they would have needed a new intake system, all the way from the filter housing to the manifold, as well as a new fuel system, pushing fuel to four different places. Going TBI meant they only needed to swap the carb out for a thorttle body, and add an O2 sensor and a higher-pressure fuel pump. They wouldn't need to redesign the intake manifold, air cleaner, or much else, really. Fewer new parts means lower design costs and much less retooling. Fun fact: Computer-controlled carbs are (were) an actual thing. Like with EFI, they use TPS, O2, and MAP sensors to regulate the fuel ratio, only instead of injectors varying their spray, they used solenoids to adjust the metering rods in something very similar to a traditional carburetor. Needless to say, the complexity prevented them from catching on.

The 305 is externally identical to the 350, so you need the same stuff for the swap. There's got to be info out there on swapping one into an XJ, if you use the Googles. I'm curious why did you chose the 305?

Your fuel tank has two hoses going from the filler to the tank, yes? The larger one is the one fuel flows through, and the other one is a vent to release air from the tank so the fuel doesn't back up in the neck. Both of the hoses should be completely free of restrictions. If everything checks out, try filling more slowly. If there are catches on the pump handle, try using a lower one, or just don't hold it all the way open. My parents used to have an old van that did something similar. If you filled at full speed, it would shut off and spray fuel at you, and then you could get another five gallons or so into the tank, but if you filled at half speed, it would shut off within a quart of overflowing, and wouldn't spit at all. The MJ's fill vent setup is better than most, IMO. Most cars don't have much of an air release, and it can get clogged fairly easily if you do a lot of driving in a dusty environment. The MJ on the other hand has like, a 3/4" hose.

It sounds a bit like some of the knocks my MJ was making with loose/missing bellhousing bolts and/or cracked flex plate. Of course you've got a manual... I don't know if a cracked flywheel would behave the same as a cracked flexplate, but you can always check the bellhousing bolts. Also check to make sure the exhaust isn't sitting against something and rattling. Does the sound change with throttle or load, clutch in/out?