Eagle

First, what kind of hitch do you have? Second, your truck is still an MJ and it still only weighs around 3,200 or 3,300 pounds. You have to watch out for the trailer pushing the truck around. Third, you need more gear. 31x10.50s with 3.73 gears work out to exactly the same overall final drive ratio as stock tires with 3.55 gears, so your final drive ratio is closer to a stock 5-speed with stock tires.

But they charged you for a complete alignment? IMHO that's fraud. The same method applies to all Cherokees through 2001, and to Grand Cherokees at least through 1998 (I don't recall about the WJs). There are hundreds of thousands of those vehicles on the road. An alignment shop that doesn't know how to align them shouldn't be allowed to have a repair license.

How can you have 9 degrees of caster if you had an alignment done? That's way out of spec. (Although positive caster should help prevent death wobble, not cause it.) Tie rod ends cannot cause death wobble. New ones can (maybe) mask death wobble to an extent, but sloppy ones cannot cause death wobble.

BA 10/5 = Internal

To replace the rear main seal, you have to remove the rear main bearing cap. That's the part for which torque is critical. You have to do it right -- I've never heard of anyone dropping an oil pan to re-torque a main bearing cap. That's nuts.

This is invalid, because the measurement can change depending on tire size, and even tire pressure. Either use the hub-to-flare method already discussed, or crawl underneath and use the method Pete referred to. Hornbrod posted a link to that in a recent thread abut lifts and suspensions.

The hub-to-flare measurement for a stock suspension should be 17-1/2" for the front. So the XJ is a 2-1/2" lift, and the MJ is riding 1-1/2" higher than stock.

Update: I found the dissected XJ proportioning valve. And, I'm ashamed to admit, it does NOT appear to work the way I thought it did. In fact, after studying it more closely, I find it's a bit more sophisticated than I thought, and ... I have no clue how it works at all under normal braking. (Which may be why the hot tip in NAXJA was to remove the cup washer and disable the dang thing). I'll post photos in a day or two.

Nope -- that's the MJ distribution block. It has no proportioning function. I did the same surgery on an XJ proportioning valve, then I misplaced it before I could photograph it. I guess I'll just have to do it again, because the question keeps coming up.

They're all the same. Just unscrew the bolt-like thing in the "nose." Be careful -- there's a strong spring inside. Once it's open, you'll see the plunger and the cup washer.

It does mean that the axles are out of square, but that doesn't mean the frame is bent. It could be caused by one of the rear spring locating pins shifting in the spring plate. It could be caused by uneven shims on the front lower control arms. And, of course ... if the front axle is off center it's impossible for axle-to-axle diagonal measurements to be equal.

The line is the hydraulic line from the clutch master cylinder. The fitting with the bleeder screw in it is the bleeder for the clutch.

So ... 2-1/2" lift. 2" is what I consider the maximum lift for staying with the stock track bar. If you add 1-3/4" coil spacers, you'll be at 4-1/4". My '88 had a 4" lift when I bought it, and the axle was about 5/8" off-center. I installed an adjustable track bar to correct that.

Bleed again for the low pressure. To cancel the light, once you have a decent peddle, stomp on the brakes HARD. That should reset the shuttle valve in the front distribution block.

I understand what a brake proportioning valve should do. And that's not how the XJ proportioning valve works. It works exactly the opposite of the way you say a proportioning valve should work. I agree that's how they should work -- but that's NOT how the XJ proportioning valve works. I've had them apart, and I cut one in half to verify how it works. It completely blocks flow (and pressure) to the rear brake circuit until the pressure in the system gets pretty high, at which point the plunger overcomes the resistance of that big spring in there and allows the rubber cup seal to move forward and open the inlet to the rear circuit. In normal, day-to-day driving with light to moderate brake pressures, the rear brakes on an XJ do not do anything. With the XJ proportioning valve, once the plunger moves forward and the rear circuit opens, the pressure to the rear is the same as the pressure to the front. Always. And that's why I don't like the idea of the XJ proportioning valve in the MJ. If the bed isn't loaded, the tail of an MJ is relatively lighter than that of an XJ. You drive it around empty, and you get used to the rear always staying where it should be -- following the front. Then one day you get into a panic stop situation, you stomp on the brakes hard, the rear circuit opens up, and the rear wheels lock up. Spin-out. Yes, the same braking with NO proportioning valve would also lock up the rear brakes. But -- if you don't have any proportioning valve, you know how the brakes are going to react so you're not taken by surprise when all of a sudden you have rear brakes.

The Metric Ton package was offered only on the LWB Comanches, so putting MT springs under a SWB is "experimental." The springs are the same, though, so I can't think of any reason not to do it. The part that bothers me is that reports on the MT springs from General are that they usually (always?) result in a lift of a couple or three inches. I'm not willing to deal with that. At this point in my life my MJs are going to be primarily street driven, or light trails (i.e. fire road type stuff) only. If I put in new springs, I want stock ride height, not a 3-inch lift in the back. Of course, in stock trim an MJ is spring under, so you could always use lowering blocks to get it back to stock height. Except that a 3" lowering block will create a LOT of axle wrap, and leave very little ground clearance.

Thanks, Don. I knew that had been posted but I don't have it bookmarked.

Sounds to me like the fuel pump ballast resistor isn't conducting. It gets bypassed on startup, so when cranking the fuel pump will run and allow the engine to start. Once you release the key to the RUN position, the fuel pump cuts out and the engine burbles along for a few seconds until it uses up the fuel and pressure in the rail, then it dies. After the truck has been sitting overnight, when you turn the key to RUN (not to START), do you hear the fuel pump run?

I'm having trouble understanding your goal. Would you be rebuilding the motor to put back in the XJ, or to transplant into some other vehicle? NEVER discard an XJ/MJ Dana 44 axle.

Exactly what did you measure that leads you to conclude that the unibody is out of square? That's possible, but extremely unlikely unless the truck was in a serious accident. The measurements as you report them suggests that the axles are close to parallel with each other (within 1/8"). For the 'X' measurement to be off by 5/8" while the axles are parallel means that BOTH axles are out-of-square with the centerline of the chassis.

Whatever you find out, I suggest that you NOT buy Rusty's springs. Fifteen or so years ago, Rusty was "da man" for XJ and MJ suspension parts. Since then, people have learned that his stuff is basically crap.

If it still has the original flares, measure from the center of the wheel (the centerline of the axle) straight up to the bottom edge of the flare. Stock 4WD XJ or MJ should measure 17-1/2" in the front. If you don't have the original flares, let us know and I'll look up how to measure from underneath, between the axle and the frame.

I wonder the same thing. Gear oil should NOT be milky gray. That's typically what color gear oil turns when it has been contaminated with water -- which would also explain why it was overfilled.

Thanks Cruiser none of the local parts stores have the bushing and there are no Napa's close so it looks like I'll have to order one . Thanks again As Cruiser wrote, go to a plumbing supply house. Pipe threads are NOT machine screw threads. Pipe threads are slightly tapered, so that as the male piece is threaded into the female hole the fit get's tighter. Whatever you do, don't try to use machine screw parts (or taps or dies) where you need pipe threads.

ZJs were also low pinion, IIRC. I would just rebuild the one you just bought. You'll need a bearing, a seal, a crush sleeve, and a pinion nut. If that doesn't work out, you can always buy another axle later, but you already know that 3.73 isn't a common gear ratio.