Eagle

Define "easy." A SBC engine does not just "drop in" to an MJ engine bay. It's a tight fit, and it requires a bunch of adapters. And after you get all that worked out -- you can't fit a radiator big enough to cool it effectively. Everyone seems to think a SBC is the answer to all situations, but it's not. Even with the sheet metal changes needed for an '86, a 4.0L swap is a lot easier and more practical, and better suited to the way most people drive/use an MJ. For an '86 with the 2.8L, the simplest, most cost-effective swap is a GM 3.4L V6.

It has to be the switch, or the wiring harness. The MJ headlights don't use relays -- the switch has a circuit breaker built in and that's the only protection for the headlight circuit.

Command-Trac referred to the 207 t-case up through 1986, and to the 231 after that. The 242 (and from 84 thru 86 the 228/229) was called Selec-Trac. Command-Trac was the base 4WD, and Selec-Trac was the option with full-time 4WD available.

The MJ does not have locking hubs, the stub axles are always engaged. What it has is a central axle disconnect on the right side axle shaft, just like on the YJ. The disconnect is vacuum actuated, and if the light is blinking on and off my guuess is that you have a vacuum leak and it is disengaging itself at random times. There's a vacuum harness that plugs onto the vacuum fittings on the shift motor. That happens to be directly beneath the oil filter, and years of oil changes may have dripped enough oil on it to soften the boots to where they won't make a good seal. If that's the case, you have two choices: Buy a new vacuum harness for about $20; or manually engage the axle, shim it to stay that way, and forget it.

The FSM does indeed say not to resurface the flywheel, and friends of mine from NAXJA who have unwittingly allowed shops to do so ended up having to later have the flywheel replaced anyway because the new clutch wouldn't work right. I have heard some people say they had the flywheel resurfaced and didn't experience problems, but IMHO it's a huge risk to take, because the cost of a new flywheel is small compared to the labor for doing the job twice. Do NOT use the slave cylinder that comes in the clutch kit. Use only factory slave and master cylinders, or you'll be replacing them within about six months.

You are correct.

^^^ That's also my understanding. "Selec-Trac" does not necessarily mean a 242 transfer case. The 242 was not used in 1986 ... which was the only year Selec-Trac was offered in the MJ.

The V6 also won't have a crank position sensor (or a place for it on the bellhousing). The 87 2.5L needs a CPS. I believe the bellhousing is a separate part and can be swapped.

Does your 3" lift include bump stop extenders for the front? 31x10.50s on stock Jeep rims will stuff inside the stock sheet metal and flares. However, when the rear axle articulates, the inside shoulder of the high side tire will rub in the rear. If you run rims with less backspacing, then the front tires will NOT clear the sheet metal, and you'll have to either remove the flares and hack the fenders, or extend the bump stops and give up a lot of articulation. If you run spacers just on the rear, with Jeep rims, you solve the rubbing in the rear without creating problems in the front. You will not be happy trying to run serious mud with 31s and a 4-cylinder. Mud needs enough horsepower to keep the wheels turning, and the 4-banger will just get bogged down with those tires. 4.10s are the right ratio for 31s with the 4.0L engine, but not with the 2.5L.

What are you trying to accomplish? You can run 30x9.50-15 or 31x10.50-15 tires on a Comanche with NO lift. With a 2.5L engine and standard 4.10 gears, I would advise not going larger than 30" tires. I wheeled even a Cherokee (which has less rear wheel well clearance than an MJ) quite happily for several years on 30" tires with no lift. If you go with 30s and maybe a 2" lift, you'll be in good shape. The important thing is to figure out what you want to accomplish, and then choose your setup to achieve that result. Don't start by deciding you "need" 'X' amount of lift and 'Y' size tires, and then asking IF that's going to work for you.

Fill it up, step on the peddle, and see where the juice squirts out. I have yet to see a master cylinder do a sudden, catastrophic fail. There's nothing in the master to blow out like that. The hose has a rubber section that can blow. Been there and done that (125 miles with no clutch!). The slave has a bellows that can blow. Been there and done that, too. (25 miles with no clutch.) The master, though, usually fails gradually and quietly, taking out the fuse panel in the process.

The TJ could be had with a D44 as an option. But that's set up for coil springs, so you'd still have to weld on perches.

Gents, I share your confusion. There seems to be a step missing here ...

JC Whitney used to carry them. Don't worry if they don't lift the MJ -- they list them for the YJ Wrangler, and as long as they are for the same rectangular headlights, they'll fit.

To do it as a drop-in, you basically have to strip the 3.4 and use the Jeep manifolds and carburetor. You get a nicer, more powerful and more economical engine if you retain the GM fuel injection, but that means some work in getting it all hooked up. Either way, you have to use the Jeep flywheel and have it neutral balanced to work with the 3.4 engine.

There is only one transmission mount -- it sits on top of the cross member and holds up the back end of the tranny and transfer case. But ... it's a different part number for each transmission/transfer case combination, so you can't just grab any XJ/MJ mount and use it. Some are rather "pricey."

The primary weakness of the Dana 35 is the point where the axle tubes enter the center section. It's weak, which allows the tubes to flex relative to the diff housing, and that puts eccentric loads on the shafts and bearings that they weren't designed to carry. It's a perfectly adequate axle for street use and light to moderate 4-wheeling, but not strong enough for handling big tires with lots of articulation. Obviously, the best replacement axle would be an MJ D44, followed by an XJ D44. Other possibilities include a Chrysler 8.25 from an XJ (96 and earlier being less desirable than 97 and newer). And then there's the Explorer 8.8. If the rest of your axle is okay, I may have a 3.07 ring gear here that I could send you. How's the pinion in your diff?

I believe he is asking about headlights, not fog lights or driving lights. The factory headlights do not use any relays. The circuit is protected by a circuit breaker built into the headlight switch, and the heavier load of high-wattage halogens will burn that out pretty quickly.

Are you saying that Motion and Clayton's do NOT have good reputations? I haven't heard anything negative about either company's kit, and I know a LOT of people who have been very happy with their Clayton's kits.

Fast idle is often caused by a dirty IAC (Idle Air Controller). However, I also found that there can be a mechanical cause. The throttle cable comes through the firewall to a ball/socket linkage (a bellcrank) mounted below the brake master cylinder. From there, there's a rod that runs up to a second ball/socket linkage, which attaches to an arm off the throttle body. After a lot of time and miles, the balls get rusty and resist allowing the linkage to move. I popped mine off, sprayed the sockets with PB Blaster, and reassembled. A few days later, after the PB had cleaned things up a bit, I popped the rods off again and sprayed a little white lithium grease in the sockets.

Raleigh, NC, got about 8 inches, and according to a friend who lives there the city was paralyzed for the first day, and nearly paralyzed on Wednesday. Dang! 7 inches for them is the biggest storm in recent memory, and even here in southern New England it's just business as usual.

Makes good sense. Fiat makes economical cars but no trucks or 4WDs (AFAIK), wants back in to the US market, and needs a dealer/distribution network. Chrysler has some good trucks and 4WDs, but nada for cars (and I've owned a couple, so I know). Marriage made in heaven. This is like an instant replay of AMC and Renault. All the same reasons. Seriously -- are you going to go to a Jeep dealer to buy a POS Italian econo-box? I mean -- Fiat has been in the American market. There's a REASON they failed here.

One of the guys in the North Atlantic Chapter of NAXJA had a BA 10/5 rebuilt several years ago. That's when parts were available, and IIRC he paid $1500 or $1800 to have it rebuilt. That's what you should be looking for. If you see a receipt for $50 ... that's not a rebuild.

Bump stops are not the problem. There is very little clearance betwen the inner wall of the tires and the fender at the rear of an MJ. When the suspension articulates (one side extended, the other side compressed), the tires tip, and the inside of the "stuffed" tire rubs the sheet metal. The solution is rims with less backspacing (which then creates other problems in the front), or spacers in the rear.

The exhaust hitting the cross member is usually because the cushion for the transfer case mount has collapsed. That's not covered by the muffler shop's warranty. Tranny mounts are expensive. You can just shim the mount with a couple of flat washers to get enough clearance to eliminate the exhaust rattle.