Eagle

Let's put this in perspective (again). The gentleman is talking about running 31" tires. With 3.73 gears, 70 MPH would be 2881 RPM in 4th gear and 2161 RPM in 5th. With 4.10 gears, 70 MPH would be 3167 RPM in 4th gear and 2375 RPM in 5th. Guys ... 2400 RPM at highway speed is NOT going to burn up the engine. I know I have posted before that this basic engine was designed long before overdrive transmissions were commonplace. Top gear used to be 1:1 (what 4th gear is in our vehicles), and we routinely cruised for long distances at 3,000+ RPM. My brother's '72 Gremlin went over 350,000 miles with no engine work, with the basic 3-speed manual tranny.

You have an 1986 4-cylinder, correct? That should have a separate, external hydraulic slave cylinder that can be replaced without dropping the transmission. Jeep began using the internal, combination slave/throwout bearing in 1987. [EDIT]Never mind -- I was looking at your signature. Your opening post said 4.0L with AX-15. Did you mean external slave? The master cylinder is always external. If you have an AX-15 with the external slave, then there is nothing inside the bellhousing to blow out or leak, but if the slave blows it could be shooting the clutch fluid into the bell housing. But the external slave with the AX-15 didn't come back until two years after the MJ was out of production. Are you sure you don't have the internal, combination slave/release bearing?

I assume the new radio isn't a factory radio, so IMHO there is nothing to be gained by restoring the factory harness. You'll have a big connector, into which you will then have to plug an adapter which then goes to the input connector for the new radio. Having done that (twice), I can tell you it's a very tight fit with the factory connector in there. The next one I do that has already had the connector cut off, I'm going to splice the connector for the new radio directly onto the cut-off wires and save all that hassle. (And space.)

Yes, it is probably the slave.

It doesn't sound like you really understood what I wrote. Yes, I ran the 3.73s with 31x10.50s. But it was NOT an optimum combination, and it was not done by prior intention. I bought the 3.73 gears to run in my XJ with 30" tires, but then the MJ came along with a lift and 31" tires (and stock 3.07 gears) before I had installed the gears, so I put them in the MJ. As I said ... the end result was exactly (and I mean EXACTLY) the same as stock tires with 3.55 gears. Not bad on the street, but nothing to brag about. And not nearly enough crawl ratio off-road. IMHO there is no question at all that 4.10s would have been MUCH better.

It's a 2WD, so it ain't a u-joint. Could be a warped brake rotor. Could be funky alignment, and the slight right turn puts one tire at just the right angle to start "scrubbing" and skipping around. I agree - not death wobble.

I have posted several times that the setup I had in my '88 MJ was 3.73 gears with 31x10.50-15 tires, and the overall final drive ratio (as proven by speed-to-RPM) was exactly the same as my wife's XJ automatic with the stock 3.55 gears and stock tires. IMHO 3.73s are better for 30" tires -- which was my plan when I bought the gears. I think 4.10s are a better choice for 31" tires. And even that isn't anything "extreme" -- that's for general purpose, combination daily driver and light trail use. For a dedicated trail rig I'd look at 4.56 gearing.

The "best" tranny for the XJ and MJ is generally considered to be the NVG 3550, and that has a much lower gear than either the Peugeot or the AX-15. The ratios are 4.01 - 2.33 - 1.39 - 1.00 - 0.78. You don't seem to appreciate that Jeeps are not sports cars, they are trucks. First gear, as you pointed out, IS for getting started. I have the NVG 3550 in my 2000 XJ and with stock tires for street driving I find it to be far superior to either the Peugeot or the AX-15. As to the last sentence I quoted above, with 3.55 gears and stock tires, 2500 RPM is approximately 80 MPH. With both the Renix and HO vehicles, I don't consider 80 MPH to be the "sweet spot." I do think the factory 3.07 gearing was a mistake, but with 3.55 gears and a 5-speed things seem to be pretty close to a good, overall compromise. Hurst makes a short throw shifter for the AX-15. You can get it from Summit Racing.

They can both be bought with Dodge badges. And a Dodge dealership is where they belong. I agree ... they are not Jeeps.

The AMC 20 is a beefy axle. The problem was that, as used in the CJs, Waggys, and Javelins and AMXs, the hubs were splined and bolted to the axle shafts and were very prone to stripping the splines and just spinning. The version used in the MJ had one-piece axle shaft/hub assemblies, which removed that problem. Also, the Waggies had 6-bolt wheels. I wouldn't do it.

We had VERY heavy rain about 4:15 or 4:30, enough wind to take down numerous branches, but didn't lose electricity at home. Then the sun came out, all was good for another hour or hour and a half -- and then we got clobbered with Round Two. More heavy rain, more wind, more branches down -- but again we didn't lose power.

The '84 and '86 engines are basically the same. But the '84 was carbureted and the '86 was throttle body injected. What I don't know is if the intake and exhaust port heights and shapes changed when the went to injection. It's worth a look. The worst case would be using the head off the other engine.

Won't help. For normal driving you don't even need a stabilizer. Either you have other problems, or you don't understand that the Jeep front steering/suspension setup is not rack and pinion and will NEVER feel as tight as rack and pinion.

If this is mostly on damp days, especially just for the first couple of stops in the morning after being parked overnight -- it's because the rear shoe lining material absorbed moisture and swelled up. Same thing happens with my '88 XJ. The solution is to replace with semi-metallic or ceramic shoes.

They are 10mm. I think Red was referring to the size socket that fits the head. Red ... that's not what designates the size of the bolt. Bolt size is the major diameter of the shank.

Why unlock the column? With the front wheels strapped into the dolly there's no way they can turn relative to the body anyway.

The 2-door XJ quarter has smaller wheel arches, and the body line creases are at a different height than an MJ. There's no way you can use a large section of quarter panel from an XJ to repair an MJ and have it look right (or match the other side). What you can do is cut sections out of the XJ wheel arch flange and weld them onto the MJ to cover/replace rust. Since the flares are very different in size, I believe the hole spacing for the flare retainers is also different, but those can be redrilled once you have a solid flange there to work on.

No.

Must be. What the heck -- a coil is a coil. All it does is convert 12 volts into 60,000 volts. It fires one cylinder at a time, so it doesn't care if the engine is a 4 banger, 6 cylinder, or "Vee Ayte."

??? There ARE NO Renix YJs. The YJ remained carbureted until 1991, when all the Jeep models changed over to the Chrysler "HO" configuration.

I think that would be correct. The thingie in the front on the XJ is a proportioning valve. The thingie in the front of the MJ performs no proportioning. It is a distribution block, AND an emergency bypass valve in the case of losing the front brakes. What I see as the flaw in your thinking is that your "solution" retains all the disadvantages of having the rear height-sensing valve but eliminates the one advantage it offers. You will still have two hard lines, doubling the length of steel tube exposed to rusting out. And you still have a 20+ year old time bomb that could explode (like mine did) in a panic stop. The better way to accomplish having constant rear brakes set for light loading is to use a single line with a Wilwood adjustable proportioning valve. Or run a single line and run smaller wheel cylinders in the rear brakes. Back up in this thread and look at the cut-away photo of the MJ front metering block. There are TWO outlets that feed to the rear. The outlet that comes out of the "nose" of the metering block is the outlet that normally feeds to the rear axle. The line from that outlet always has full pressure. It goes into the rear height-sensing valve, where the valve proportions how much of the pressure is allowed to go to the brakes. The outlet on the front bottom is the emergency bypass. Normally, it is blocked by the sliding shuttle valve that runs horizontally across the top. If you lose the front brakes, the pressure differential causes that shuttle valve to slide, opening up the bypass port. (NOTE: As was commented when I first posted the photo, the unit in the photo is DEFECTIVE! The factory did not finish boring the hole for the bypass circuit, so it looks like that outlet has no fluid supply.) That outlet has a hard line that tees into the rear circuit AFTER the height sensing valve, so when in bypass mode you always get full pressure to the rear brakes. Yes, you could simply block the front/bottom out let on the metering block and block off the tee fitting after the height sensing valve to eliminate the bypass circuit. That, IMHO, would be a very poor approach. You will still have a 20+ year old height sensing valve that may explode in a panic stop. At least if you leave the height sensing valve connected to the actuator rod you would be offsetting the risk by having a functional height sensing valve. If you are just going to fix the arm in one position, why risk driving ab=round with a time bomb when you can eliminate that and use a device that's MADE for the purpose -- the Wilwood manually adjustable proportioning valve?

Two points: First, a Dana 60 is a BIG and HEAVY axle. It's pretty much serious overkill for a Comanche. What size tires are you planning to run? Second, there's a big difference (2 inches) between 68" and 70". Your post makes it sound like you regard that much difference as no big deal, but it could be a VERY big deal. With a standard (factory) MJ rear axle, the tires ride very close to the rear springs and the the frame and inner fender. Running 31.10.50s on factory rims, I came back from every off-road trip with new black rubber scuff marks on the insides of my rear fender liners. Awhile back, someone had a home-brewed spring pack undo itself (I don't recall if he omitted the spring clamps, or if they broke) and slashed the sidewall of a tire when one of the leaves turned just a little bit in the pack. You need to take some measurements, figure out what size tires and wheels you'll be running (including backspacing), and see if that monster will even fit under there. (Or, going the other way, how wide you'll need for flares if it's a lot wider than a stock axle.)

Let's try a bit of Sherlock Holmes style deductive reasoning. The problems occur after it reaches operating temperature. During warmup, it runs in "open loop" mode, ignoring certain sensor inputs and using a programmed fuel map in the ECO to control the fuel delivery. Once it warms up and switches to "closed loop mode." it then responds to input from sensors. Clearly, then, the basic systems are okay and the problem lies with one (hopefully not more than one) of the sensors that get bypassed in open loop mode. The oxygen sensor is one of those, so that's one to check. Not sure if the MAP sensor is skipped in open lop mode. What else is there?

I suspect the difference is that the Peugeot may use the other set of mounting bolt locations for the crossmember. There are two sets, one being 4" farther to the rear than the other.

Rear main seal in a can? :rotf: :rotf: :rotf: