Eagle

Nope. The Clayton kit includes a complete new crossmember. The two outer ends, which also incorporate the mounts for the arms, bolt to the unirails at the point where the rear section is nested to the front section, providing a double thickness of steel. In addition to the bolts, the end pieces are welded to the uniframe sections. The center portion of the crossmember is bolted in between, so it's removable for tranny service. He designed it to mount where it does specifically so there would be enough thickness there to weld to. It's VERY strong. There are a LOT of his kits out there, and I've never heard of one breaking or tearing loose from the body.

Not really. All timing does is optimize the amount of power you can get from the gasoline you're burning. The key is that you need the fuel-air mix to ignite at a time when the expanding gases resulting from combustion will be pushing down on the piston after it has passed top-dead-center, and not before. The combustion isn't an instantaneous event, and that's the problem. If the "event" starts too soon, the pressure starts to build before TDC and you lose power because some of the combustion is actually slowing the piston down as it rises toward TDC. In extreme cases, the expanding flame front slams into the piston destructively, with the flame front slamming down and meeting the piston as it's rising up (rather quickly) -- that's what we call "detonation," or "ping." Ping IS a destructive event, which is why we don't want to hear it -- ever. On the other hand, if the combustion "event" starts too late, the piston will have gone beyond TDC and started down again, leaving a larger combustion chamber and resulting in lower compression. Some of the energy produced by the "event" will thus be lost -- or at least used less efficiently. Now ... what most folks don't understand is that ALL gasoline contains the same amount of energy per unit of volume. Octane doesn't add any energy or power to the gasoline. All octane does is slow down the rate at which the fuel-air mix burns. What that accomplishes is that it slows or reduces that advancing flame front, allowing the timing to be advanced farther before TDC so that the event can begin earlier, with the goal being that when the piston reaches TDC the combustion event will be reaching maximum expansion, thus generating maximum power. Going back to my old 199 c.i.d. Rambler American, I don;t remember the "official" timing spec, but I think it was around 4 degrees. And it was for regular gasoline. By switching to high-test, I was able to take advantage of the delay in the flame front and dial in quite a bit more advance than what the actory called for. The dealer who sold me that car was a family friend. My grandfather began buying cars from his father before WW2. I mentioned to him one day what I had done and what kind of gas mileage I was getting. He nearly had a heart attack. "Geez," he said, "don't let anybody hear you say that. My God, if anyone hears that ALL my customers will be coming in and asking why they don't get 28 miles per gallon." So ... more timing might mean more power -- if the gasoline is properly matched to the timing spec. Too much timing advance with a low octane gasoline, though, will blow the tops out of the pistons in a VERY short time.

See other thread ... Your gearing should be 3.07 if 5-speed, 3.55 if automatic.

What book says to resurface the flywheel? I know the Jeep FSM specifically says not to resurface. To quote: "Minor scratches, burrs or glazing on the flywheel surface can be reduced with 180 grit emery cloth. However, the flywheel should be replaced if the disc contact surface is severely scored, heat checked, cracked, or obviously worn. Flywheel machining is not recommended. The flywheel surface is manufactured with a unique contour that would be negated by machining. ..."

2 to 8 degrees is too low. The FSM and all the aftermarket manuals agree that timing is not adjustable on the 4.0L so they don't provide timing specs. But -- the 2.5L began life with adjustable timing and then it became non-adjustable when it went to the same Renix-based ignition as the 4.0L. The initial timing listed for the older 2.5L engines is 12 degrees. Then we should keep in mind that the 4.0L is essentially the same engine as the older AMC 199/232/258 6-cylinder engines. For the 258, 1983 is the last year I have tune-up data for. The timing for that year is given in Haynes as 15 degrees -- and 19 degrees for the high-altitude models. Initial advance was less way back in the 60s, but I remember that I used to run my 199 c.i.d. I-6 at 12 degrees, which was more than called for but I ran high-test gas to eliminate the knock problem. I also got 28 MPG highway, which was the purpose of jacking the timing beyond factory spec. With the Renix 4.0L, the initial advance can be pushed way up because the system has a knock sensor, and what that does is retard the spark when it sense detonation. In fact, the Renix system has a high-altitude CPS available, and that version of the CPS provides more initial advance than the "flatland" version. I've been running a high-altitude CPS in my '88 XJ for years. My house sits at elevation 475 feet above sea level, and I have no problems with detonation.

Dealer

It isn't just the quality of the welds that's a concern. Clayton is, by training and profession, an industrial engineer. His kit wasn't thrown together. He wheeled a ZJ (which is what the kit was first developed for) and he looked hard at what he broke each time he was out. Then he engineered a long arm kit that was optimized to be more than beefy enough where things get stressed, without being made of cast iron and weighing three tons. He also had the knowledge to evaluate what was needed in the way of purchased components, such as rod ends (I think he used Johnny joints, but I don't recall). That's why I stressed design and engineering. If you don't understand how this stuff works, you can make up a finely crafted pile of hardware that'll kill you in a heartbeat. Keep in mind, too, that materials have a cost. You asked for "cheap." If you as an individual were to set out to build your own clone of a Clayton kit -- I seriously doubt you could produce just one for less than what he sells his for.

Someone else encountered the same problem when doing a cluster swap, if I recall correctly. Wasn't me. Try searching -- or maybe whoever it was will see this thread and jump in. It's not a bad bulb. Bad bulbs don't light up.

It was external in 1986 (and 84 & 85 in the XJ). It went internal in, I believe, 1987 (maybe 1988), and then went back to external in 1994.

I understand that money doesn't grow on trees and that you may feel you can't afford an "expensive" professional long arm kit. I know I can't. But I've seen a number of home-made long arm kits, as well as being in Clayton's shop watching how his stuff is fabricated, and being on the scene while he was installing a kit for one of my friends in NAXJA. I gotta tell you, the home-made stuff was so scary that I didn't want to be within ten miles of it -- literally. A poorly designed or poorly engineered or poorly fabricated/installed suspension won't just leave you stuck -- it can kill you. You do NOT fool around with that stuff. If you can't afford to do it right, stay with a 3" lift and 31-inch tires until you CAN afford to do it right. I know this will sound melodramatic, but considering what I've seen -- it's not: How much is your life worth?

I am not certain, but I strongly suspect that the rear brakes for the AMC 20 axle are the same as the parts for the Dana 44 with 10" x 2-1/2" drums. I overlooked the part of your post about documenting the brakes. All you need is a parts listing -- the brakes for an 88 or 89 4.0L are the exact same brake parts as for an 86 2.5L and 2.8L. More than likely Brent (BLHTAZ) could provide you with a factory parts manual exploded view of the front brakes with the accompanying part numbers, which would show that both years and all engines used the same brakes from 86 thru 89.

Factory spec is 13 psi (minimum) at warm idle, and 35 to 75 above 1600 RPM. If you don't drop below 20 psi, you're in good shape. Highway cruise should be between 40 and 55 psi, but if it's only 35 I wouldn't fall on a sword because of it.

Yes. When cold, the bottle should be half full. At operating temperature, the coolant expands, which is what creates the pressure. At operating temperature there should be almost no air space in the surge bottle.

The '90 front brakes are actually worse than the '86. 1990 was the first year for the new, composite rotors. They provide no better stopping power, but they are MUCH more likely to warp, and those were the rotors that were the object of a massive recall because the sheet metal "hat" portion was rusting away and leaving Jeeps with no front brakes. In addition, all the related parts are different due to offset dimensions. I've posted the parts compatibility list several times. To change to 1990 brakes on an '86 you have to either eplace the entire front axle, or replace the knuckles, hubs, calipers and rotors. That's a lot of work to go through in exchange for inferior brakes.

Oh, I understand the implications of funding. That's how I ended up running 3.73 gears with 31x10.50 tires. The gears had been bought for use in an XJ with 30x9.50s, then the MJ came along and followed me home. 31" tires with 3.07 gears were predictably sucky and I had the gears, so I had 'em installed in the MJ. It was a decent combination on pavement, but it didn't turn it into a rocket ship. And off-road, the crawl ratio was deficient.

Correct. The bigger the better. Off-road tires with sizes like 31x10.50-15 or 33x12.50-15 are called "flotation" tires for a reason -- they were intended to be large, oversized tires that would "float" over sand. As Pete said -- air down. You want to spread the load out over as large a contact patch as possible. Locked is good, both axles locked is better. The last thing you want/need in loose sand is one wheel digging a hole while one or more another wheels just stand around and watch. Also, speed is good. Stopping is your enemy. A few years ago I went to Chile at the invitation of NAXJA member "Mike in Chile" to see what kind of trouble I could get into with his "Total Traccion" 4WD club. Near the coast of Chile they have a HUGE area of pure sand dunes, about 12 miles wide and 20 or 25 miles long. That's where we went. Two of the guys on street tires got hopelessly stuck right at the entrance. Mike's (wife's) XJ did pretty well, but eventually we got to one very high, very steep dune that everyone wanted to climb, and nobody good. Roberto, driving a very well-prepped older Toyota Land Crusher could only make it halfway up -- and he was our rescue vehicle. And then we heard in the distance the sound of an ENGINE. I don't mean just any engine -- this sounded like a NASCAR stocker with open pipes. (As it turns out, the engine was basically a NASCAR engine.) "Ah," said Mike, "here comes El Gachito. Now you'll see how to drive the dunes." And then over another dune comes this ... thing. It began life as a Camaro, but it had been stripped, fully caged, had axles on it that must have been three feet wider than the tub, and about the biggest, widest tires I have ever seen. And, of course, the afore-mentioned NASCAR engine. He pulled up, watched for a few minutes as the other guys made more futile attempts to crest this monster dune, then headed toward his beast. "El Gachito" didn't speak English, but through Mike he asked if I'd like to ride shotgun. "Go for it," said Mike, so I accepted. So El G fired up the beast, backed off about 100 yards, and took a run at the dune. He started rolling slowly, and just before the base of the dune he planted his foot and in the passenger seat it felt like I was in an F-15 hitting afterburners on a short runway. The thing took off -- and we made it about 2/3 of the way up. Farther than anyone else had gotten, and we weren't dug in down to the axles and needing to get dug out like everyone else, but we didn't top it. El G muttered something in Spanish that I remembered from 7th grade Spanish class as indicative of bovine excrement, backed down to the starting point, moved a wad of rags on the floor between the seats and reached down with a wrench through a hole in the floor pan. I pointed and shrugged, asking "WTF?" "Quatro por quatro," he said. Yeah -- this dude runs the dunes 90% of the time in 2WD, relying on the flotation of the huge tires and pure speed to keep him from sinking in. He gets very unhappy if he actually has to use 4WD -- but in this case he had to. So he gets it into 4WD, stuffs the rags back in the hole, and takes another run. This time he hit the loud peddle a little earlier, too -- and we crested the dune doing probably 40 MPH, like it wasn't even there. Speed and flotation are your friends in sand. And there endeth the reading for today.

:agree: that is why i replace them with 3.55 after the d35 gear got chewed up a bit Not much of an improvement. Running 3.73 gears and 31x10.50 tires only gets you back to the equivalent of a stock 3.55 ratio on stock tires. 3.73 is a good ratio for 30" tires (which was the plan when I bought the gears), but for anything larger you need at least 4.10s or maybe even 4.56.

Asking for "cheap" in a long-arm suspension conversion is asking for disaster. I like Clayton's, in large measure because I have wheeled with him and I know that the suspension was designed to stand up to the way he abuses it. http://www.claytonoffroad.com/index.asp ... herokee!XJ

I feel left out ... I don't see a logo OR a little box with an 'X' in it.

It might help to post a photo of what the kit includes.

You didn't say if it's a 2.5L or a 4.0L. Keep in mind that the TJ front axle is a low-pinion D30, so it's okay for street and light (dirt road) 4x4 use, it's nowhere near as strong as the high-pinion D30s used in the MJs and pre-Y2K XJs. If you're looking at a lift in the future, the low pinion means you'll start encountering pinion angle problems with less lift than if the axle had a high pinion.

I use Purolator filters. The Mobil-1 oil filters are also supposed to be excellent. JUST DON'T USE FRAM!

Are you by any chance running a FRAM oil filter? If so, there's your problem ...

It's called "headlight sentinal" and it was an option at least as far back as 1988. My XJ has it. I believe it's just a small module that snaps in between the headlight switch and the under-dash wiring harness. In fact, a lot of XJs and MJs had it. You may have it and not know it. It doesn't work like the auto-off feature on a lot of foreign cars, where you can just leave your headlights switched on 24/7 and they'll always turn off after 'X' minutes. The headlight sentinal requires you to turn the lights off manually, or they'll stay on until the battery is dead. If you switch the lights off before turning off the ignition, you'll never know the option is there ... the lights just turn off. However, if you switch off the ignition first, THEN turn off the headlights ... they stay on for one minute.

It's no different ... and the XJ/MJ fuel pump is known for burning out if the tank is allowed to run too low. The pump needs the liquid around it for cooling. That's the way it was designed.