Eagle

Tire balance. That's the ONLY thing that causes vertical wheel tramp.

Adding another leaf DOES increase the spring rate significantly, but that doesn't make it harsh. One of the 4x4 magazines ran an article some years ago on how to calculate spring rates. I don't have the article any more but, basically, if you add one leaf of equal thickness to a pack that was 4 leaves, you increase the rate 25%. Add one leaf to a pack that started out as 3 leaves, and the rate increases 33%. I've done multiple XJs using cut-off XJ main leaves as an AAL and they generally provide about 1-1/4" of lift. One guy in NAXJA had an almost new 2000 and used main leaves from an almost new '99 and he got 1-1/2" of lift. The ride is not harsh -- in fact, IMHO it's better than stock. Keep in mind that those numbers are GROSS lift. If the original springs have sagged, the net is obviously less. The XJ I did for an ex-GF was already sagged about 1/2" to 3/4" so even though the AAL grossed 1-1/4", the net was only about 5/8" higher than stock. I had expected to need 3/4" coil spacers in front to level it out, but the net result looked good with just the rear AAL so I didn't bother. For an MJ, if the original springs have sagged a lot, then using cut-off MJ main leaves as AALs would be a good way to go. I picked up an '89 LWB that hasn't sagged too much, but I want a bit more carrying capacity without a lift, so I'm going to use XJ main leaves. The concept is that they'll add capacity without adding as much lift as MJ main leaves.

The causes of death wobble are many, and diagnosis can be very difficult. Sometimes it's a combination. You need to consider: * Tire balance * Loose track bar * Loose track bar frame bracket * Worn ball joints * Worn tie rod ends * Worn control arm bushings * Caster angle (too little caster can result in DW) * Worn steering box or pitman arm * Worn drag link TRE * Warped front brake rotors * Worn hub/bearing units * Out-of-round rims * Out-of-round tires IMHO the two most critical are tire balance and caster angle. I know a lot of people say "TRACK BAR!!!" is THE cause -- but I drove around for six months with a track bar so loose I had about a quarter turn of free play at the steering wheel, and not a hint of death wobble. So I'm unconvinced on the universality of the track bar as the, or even a, primary causal factor.

Probably a wise choice. I've been using the '88 SWB as an all-around truck, and I've lost count of how many times I have wished I had a slightly longer bed for hauling. I picked up (no pun intended) an '89 LWB with a blown tranny and no driver's side floor that's scheduled to correct that problem, if I ever get a few $$$ to throw at fixing it up.

What's going to be the purpose of going to 4WD and lifting? IMHO its pretty simple -- for all-around use as a truck, the LWB is far more utilitarian, and can also be used for an occasional off-road jaunt. The SWB wheels far better than the LWB because it has a better over-center angle and a better departure angle. It's also more fun to drive on the street ... but it doesn't haul as much stuff in "truck" mode.

Sorry. I was asking the original poster -- but it applies to anyone with skip/miss in the engine. Check the plug wires.

Are you running new spark plugs AND new spark plug wires? Missing/skipping under load is a classic symptom of bad ignition wires.

I have never heard of anyone replacing the mechanical speedo with an electronic one. I suppose it can be done if the electronic one runs directly off the electrical feed from the sensor in the transfer case, but I don't know if that's the case. If the speedo runs on a data signal that comes through the ECU, you're hosed. Even if it's possible, it's going to take a bit of work. Personally, I'd buy a new speedo cable and call it good.

There is a reason the stock exhaust is 2-1/4". Many years ago, when my brother was managing a Speedy Muffler shop, he talked me into replacing the stock exhaust with a 2-1/2" cat-back system. BIG mistake! I lost gas mileage, and I lost low-end torque. The trade-off is that you supposedly gain high-end horsepower. But ... you're talking about a 5-speed with tall gearing. Your RPMs at 75 MPH are under 2500 RPM. That's not exactly the high end of the RPM range. You do NOT need a 2-1/2" exhaust to run down the highway at 75 MPH in 5th gear. As for running with no muffler? One 25 mile trip and you'll regret it. I hope you have a good stereo with good speakers.

Do you regard stroking a 350 Chevy block to 383 a "cheesy upgrade"? If not, why would this be any different?

Rusty's track bar comes in two lengths, depending on the amount of lift. The shorter one will adjust short enough to run at stock height ... but (at least on my '88 MJ) at stock height the bend doesn't clear the diff cover, so it becomes an interference fit.

Good luck. There is a difference, because when I put a '92 or '93 track bar in my '88 XJ the steering wheel was off-center by about 1/8 of a turn. But you cannot see a difference by looking at them. I spent a half hour with two parts guys at the dealership one Saturday morning with the old and new style track bars laid out on the counter, trying to see what was different and why they have different part numbers. Any way we measured, we couldn't find the difference. Whatever it is, it's not enough to put your axle off-center by an inch. Have you compared your axle bracket and frame bracket to another stock XJ or MJ to be sure they haven't been damaged or modified?

I have two of them here with 3.55s. 4.10s were for the 5-speed.

Yeah, I've heard that. Don't tell VW, Audi, BMW or Mercedes -- they haven't gotten the memo.

Take a good luck at the routing of the speedo cable, under the dash and under the hood. It's very possible that in changing the clusters you pulled more cable through the firewall and made a tighter bend under the hood. This could make it bind at that point where it didn't before if it had a smoother, larger radius.

I have never seen a factory hidden winch in the U.S. -- ever. When I visit my wife's family in Santiago, Chile -- they're everywhere. Mostly on Cherokees, but I did see one Comanche a couple of years ago that had the winch.

Gotta love them dealers. I used to own (in addition to my Jeep at the time) a 1993 Honda Accord LX -- the mid-level model of the Accord. Mine didn't have a rear sway bar, but the pricier EX did. So I went to the dealership to buy the pieces to add a rear sway bar. The parts drones told me it couldn't be done. I questioned it, and they called the parts manager over and he said the same thing. I asked why. He didn't know -- he just knew it couldn't be done. So I went to the general manager, and complained that the parts department was refusing to sell me probably $300 worth of parts because they didn't think I could do what I damned well knew I could do. He said he'd look into it. Several days later, he called back to say that he had confirmed that the parts guys were right, the EX rear sway bar could not be fitted to the LX model. I asked why not. "Because the EX has dual exhaust, and yours has a single exhaust," was the answer. Sounded reasonable -- except that I knew better. My ex-wife had an EX one year older than mine, and my brother at that time managed a Speedy muffler shop. Both models had exactly the same exhaust, except that the EX muffler (which was mounted at the very back of the system) had two chrome outlets where the LX had a single chrome outlet (and the DX had a single non-chrome outlet). I wrote the owner of the dealership a letter explaining exactly why his parts guys and his general manager were idiots, and I never went back to that dealership for anything.

Synthetic oil isn't thinner than conventional. "Thinness" is viscosity, and synthetic oil actually maintains its viscosity better than conventional oil. The "problem" is that synthetic oils have more and better detergents than conventional oils, so they tend to clean out gunk and deposits that the dinsaur oils leave behind. In the case of old seals, removing the deposits removes the stuff that's been doing the sealing. Once the gunk is gone, it'll take a long while before it builds up enough to close the gap again -- if it ever does. I think you need to bite the bullet and just replace the rear main seal. It's long overdue anyway.

Those rims will move each tire outboard by 1-3/4". Combined with the fact that 30s are a tad wider than the largest stock tire size (225/75-15) it is virtually guaranteed that your tires will be clobbering the flares whenever the suspension compresses. Unless you plan to remove the flares and trim a lot of sheet metal, especially in the front, it is best to stick with stock rims up through 31x10.50 tires. With an MJ, anything larger than that on stock rimes will be rubbing the rear springs and the inside of the rear fenders so you'll then have to use rims with less backspacing, but at larger than 31" tires you would probably want to trim anyway.

Be sure to replace the line/hose that connects them. Otherwise one fine day you'll find that you have no clutch. Ask me how I know ...

If this is the truck's first New England winter, I would strongly advise getting the underside power washed and having the chassis and underside of the box rustproofed.

The original poster doesn't have a '91. In the Renix models, the ECU is not involved in controlling the aux fan. The temp sensor in the radiator is an off-on switch that controls a relay, which in turn controls the fan. Since the original temp sensor from the radiator tank won't fit the smaller hole in the t-stat housing, you had to have used a different sensor. If you used the one for a '91 and newer XJ/MJ, it's NOT a switch, and it will not turn your fan on. This is just one of the reasons why I don't advocate doing the open system "upgrade." NAXJA members spent years looking for a sensor that would do the job. One guy said he found it in an older Honda. Three other people showed why he was wrong. Then someone said a Corvette temp sensor was the answer. IIRC that, too, proved to be a false lead. I'd suggest getting the one for an '88 MJ that has idiot lights. That's an on-off switch. If the temp gets hot enough that it would trigger the warning light -- that's when you want the fan to come on. Of course, I'd rather have it come on a tad sooner, but that's better than nothing. You can also wire a toggle switch in parallel with the sensor so if you see the temp rising you can switch on the fan manually.

Welcome, Belto. If you have technical questions that you can't express in English, send them to me in Spanish. My Spanish is terrible, but my wife is from Chile and she may be able to translate. If not, I met her through a Jeep friend in Chile who speaks English pretty well, so we'll be able to get you some kind of answer. www.quadratec.com has a lot of stuff for the Cherokee, and many Cherokee parts also fit the Comanche.

I doubt it. I think the quality of the service manuals is inversely proportional to the size. The by-pass was pretty well covered in the old AMC shop manuals, which is how I know about it. It is mentioned in the '88 FSM for the 4.0L engine. In the '94 FSM, which covers both the XJ and the YJ (Wrangler), they don't show it or mention it under the 4.0L engine but they do show it under the 2.5L engine. I don't think they would eliminate it from one but not the other. I guess I have to dig out a 2000 FSM and see if they discuss it in that. AFAIK oil filters have always had an internal by-pass.

The illustration I have from the '88 FSM shows it in the block, behind where the oil filter adapter mounts to the block. That's where I remember it being from the old AMC days. Problem is, they show it in detail for the 4.2L engine, but that engine has the filter mounted directly to the block the way the old AMC engines were set up. I am left to assume (which is always dangerous) that the same parts are in the block behind where the 4.0L oil filter adapter bolts on. It's basically a spring and a plunger. I really wish I had a functional scanner ... but I don't.