Eagle

THAT would have rated an STND* * Small ThermoNuclear Device

General rule of thumb when working on any vehicle that has been out of production for more than twenty years -- don't scrap or trash ANYTHING. Many years ago a couple of friends and I found a back-country junkyard (really a farmer's back field) that had a couple of Hudsons in it. We were all active with Hudsons at the time, so we took a road trip up to see what he had. A few early 50s sedans, nothing special and nothing there we wanted or needed. Then he mentioned that he had recently chopped up a '46 Hudson pickup. YIKES! Most people didn't know Hudson even made pickups, and they only made them for two years after WW2: 1946 and 1947. (And they made one 1948 prototype, in the new "step-down" body style.) You think MJs are rare? Try Hudson pickups. So after telling us (as if he'd done a good thing) that he had scrapped a Hudson pickup, he proudly announced, "But I saved the rear axle." :doh: The rear axle of a 1946/47 Hudson is just about the ONLY part that nobody other than an absolute purist would ever want. The trucks were overbuilt and very strong, but the rear axles were (to be charitable) junk.

Yes, that's what we're saying. Please post your mailing address so I'll know where to send the letter bomb you have just earned.

Dakota tails look similar, but they aren't even close in any dimension. Making them fit would be as much or more work as fitting '00 Cherokee tails. Here are Pete's photos to prove it: http://comancheclub.com/topic/46115-dakota-replacement-taillights/

Personally, I'd return it to where I got it. It's obviously the wrong part.

Actually, all you need to clear 31s is to put 31s on the truck. I've run 31x10.50s-15s on my '88 MJ after removing the lift, and I currently have 31x10.50-15s on the '88 Cherokee -- at stock height.

I have no idea what the ride height would be in an MJ. Would you mount them as spring under? I don't think they're a good choice for a pickup. I used to have a '78 full-size Cherokee. I bought it used, and the rear springs were sagged so badly that if I used a jack under the rear axle, I couldn't take a tire off without also jacking the body away from the axle to make clearance. I put in a Rancho full-length AAL that was supposed to generate 2 inches of lift -- that got it basically to where it should have sat for stock ride height.

If I remember correctly, the Grand Wagoneers were spring over, like the XJ. That would mean the Waggy springs start out with a LOT less arch.

I don't think the Ranger springs can be flipped. It would have to be checked, but usually the leaf tip spacing is tight at the front end and pretty wide at the tail. Reversing a spring like that would result in some potentially strange ride and handling characteristics.

The centering pins for the MJ springs are not centered on the length of the main leaf, they're off by something like four inches. How does that compare with the Ford springs?

The 2000 XJ doesn't have spindles. It has hub/bearing units. Did you get the steering knuckles from the 2000? If not, the other parts aren't going to help you because the calipers won't be centered on the discs.

What happens when you run tires on rims that are wider than recommended is that the tread tends to arch up (away from the pavement) in the center of the tread. The result is rapid wear on the outer edges and the shoulders. To counteract that, you have to run the tires at higher pressures to get a flat contact patch. But ... that pressure may be higher than the maximum recommended for the tire.

I finally found ONE Cooper tire that's still offered in 15-inch sizes. For the 225/75-15 size they list the approved rim width as 6" to 7".

You are still creating a lot of confusion by continuing to use the term "cranking" for when you mean "starting" or "firing up." "Cranking" is what happens when you turn the key and the starter motor turns the engine until the engine fires up and runs by itself. An internal combustion engine can "crank" all day (until the battery runs down) without ever starting.

Do you know what the stock rear height from fender to center wheel in inches??? I just installed 2" rear shackles and just curious where I'm at now in the rear. Use the method in Hornbrod's link: http://comancheclub.com/topic/11098-how-to-measure-ride-hight/?hl=height I think the hub-to-flare measurement or a stock MJ is around 20-1/2 to 21, but I've never verified that.

Going back a decade, the "hot" trick in NAXJA was to just remove the cup washer and spring, and leave the plunger/piston in the forward position (pulled into the cap nut, leaving the orifice open). I never heard of anyone having a problem doing that. After following Shelbyluvv's link, that led me to another video in which an older gent with a southern accent discussed proportioning valves. He claims they are all just pressure limiting valves. Dunno. It was a long video, at the end of which I knew nothing more about how they actually work. Or if they're really needed. The first car I had with front disc brakes was my first 1968 Javelin. Disc front/drum rear, and it did not have a proportioning valve. However, the 1968 AMX (which was the shorter, 2-seat version of the Javelin) did use a rear proportioning valve. Shorter wheelbase ==> more tendency for weight transfer to the front, thus greater tendency to spin out under heavy braking. One of my friends bought a used AMX. Drove it home a few miles from where he bought it, and all the brakes locked up and burned up the linings. Turned out the previous owner had used ATF in the brake system, and the ATF caused all the seals to swell up. Most of the parts were available or rebuildable. What we could not find (or figure out how to rebuild) was the rear proportioning valve. So we just eliminated it. We knew what it did, so we took an alternate approach to reducing the braking at the rear wheels. His AMX was a 343 c.i.d. V8. We used wheel cylinders from a 6-cylinder Gremlin. They were smaller in diameter, and we calculated that would reduce the rear braking power by about 25 percent. He drove that car for twenty years or more like that, including autocrossing it, and never had a problem. I wish there was a new manufacture ( or quality rebuilt) source for the MJ height sensing valve, because they way they operate makes a lot more sense to me than the black magic of the XJ combination valve.

Here's a closer view of just the proportioning valve segment of the XJ valve. The upper vertical passage to the left is a full-pressure by-pass for the rear brakes in case the fronts fail. Under normal conditions, the shuttle valve blocks it off (as shown). If the front circuit loses pressure, the shuttle valve moves to the left, opening the straight-through path to the bottom output passage. That much is easy to figure out. What's less easy is how it works under normal conditions. The input is the vertical passage at upper right. The fluid (and pressure) come down that passage and into the chamber the right of the cup washer on the piston. Then somehow the fluid and pressure have to get past that cup washer and into the lower vertical outlet passage at the lower left. I don't get it.

Interesting video, but IMHO useless. The XJ proportioning (or "combination") valve and the MJ distribution block don't have what he referred to as a "metering valve" in the rear of the block. His explanation of how the proportioning spring works doesn't at all correspond to how it seems to work based on what we can see by cutting one open. His explanation of the shuttle valve operation is backwards. I'd like to see an example of the valve in that video sliced open to show how it works.

here's a photo from an older thread on this site: The 2000 and up TJ bearing is on the right, its got longer studs and you can see how the WMS is shorter. Source thread: http://comancheclub.com/topic/39809-wj-knuckles/?hl=hubs

A couple of people have commented on the way the leaf retainer bolt in the rear springs can start to wear a groove into the upper surface of the main leaf. I've seen that myself. Awhile back I took apart two pairs of broken MJ leaf packs, mixed and matched parts, and managed to put together two complete springs out of the parts from four. In the process I was reminded that not all MJ leaf springs have the retainer bolt in contact with the main leaf. On some there's about a quarter of an inch of clearance, as shown in this photo. Does anyone know which springs got the extra space and which didn't? These were all standard 3+1 MJ springs, no metric ton stuff here.

XJs don't need any special tools. Bleed normally (start at right rear, progress to left front last). If the shuttle valve hasn't reset to cancel the warning light, stomp on the peddle a couple of times to reset it.

That's the horizontal plunger across the top. Both the XJ and MJ units have that. It's cleverly called the shuttle valve, and it also actuates the brake system warning light. You can see how the plunger for the switch is down in the narrowed "neck" of the shuttle plunger. If the valve moves in either direction (caused by a failure of either the front or rear cirsuit), it'll push the plunger up and turn on the light. It's how that lower, proportioning plunger in the XJ valve works that has me puzzled.

The problem is that the hubs have slightly different offsets for different years. I'm pretty certain that the YJ and the TJ did NOT take the same hub, so whatever year front axle you have, there's a good possibility these hubs won't fit. The above is from my manuscript, which is copyrighted to me. Please do not disseminate by any means.

The stars finally aligned, my camera batteries weren't dead, and my Internet connection was functioning. I found the XJ proportioning valve I had sliced and diced, so I can now post photos to show how the XJ proportioning valve is different internally from the MJ front distribution block. First up, the MJ distribution block. I've posted a photo of this one before -- this photo is touched up to show how the emergency bypass circuit is supposed to run: And now the XJ proportioning valve. Notice the plunger, spring, and rubber cup washer. That's the proportioning mechanism, but after studying it I can't figure out how it works. If you look closely, you'll see that the outer surface of the rubber cup washer has ribs, so perhaps the ribs allow brake flow until the pressure gets high enough to compress the ribs and allow the cup to seal against the bore? Dunno. I also realized that the XJ valve has a bypass, similar to the MJ, so if the front brakes fail the rears will get full flow and pressure, not proportioned.

Not legal. Federal regulations require that fog lights MUST NOT operate when the headlights are on high beam.