Eagle

My bad. I thought that was only on the J30

I just wanted to let you know that your Comanche couldn't have came stock with a D44 anyways. There were no shortbed Comanches that came stock with a D44. The D44 came stock under the Metric Ton Comanches and all Metric Ton Comanches are longbeds. I hope this info helps. Sorry, but that's not correct. The Metric Ton package wasn't offered on the shortbeds, but the D44 axle came with other packages. I have an '87 shortbed that I bought from the original owner's daughter. It's all stock, and it has a Dana 44 rear axle -- with Trac-Lok.

Wait - Are you asking about an AMC Model 20 axle for an MJ, or about an axle out of a full-size J20 pickup? A Comanche Model 20 axle is about equal in strength to the Dana 44. The axle out of a J20 is going to be a different width and have 6-bolt hubs. Not a bolt-in conversion.

You go to an auto parts store and you buy a temperature sender and an oil pressure sender for a 1988 Cherokee or Comanche with gauges. The senders are the same for 4-cylinder and 6-cylinder. The tachometer is not the same, but the correct 1988 tach has a potentiometer that allows you to recalibrate a 6-cyl tach to read correctly with a 4-cyl engine.

There will be a bigger difference the first time you go around a bend in the road. The front wheels travel farther than the rear wheels around corners. That's why you shouldn't run part-time 4WD on dry pavement.

Awhile ago someone posted photos of an MJ with the newer XJ taillights. So it has been done, but it is very much a custom job. The shape is completely different.

It fits, but you have to be aware of differences between years. There are three possible dash clusters. The "early" XJ/MJ cluster was used from 84 thru 86 (and maybe partway into 87, I haven't verified that). It has a mechanical speedometer with the cable attached to the cluster with a metal retairer and screw. The second variation was used from 1987 thru 1990, also has a mechanical speedometer, and the speedo cable is attached to the speedo head with a which nylon retainer. From 1991 through 1996 the XJ (and 91 - 92 MJ) used an electric speedometer.

He may also have damaged the front hub/bearing unit on that side.

75 is the top legal limit I've seen anywhere, even in the western states. Let's put this in perspective. I have to periodically remind you youngsters that the engine on which both the 4.0L and the 2.5L were based was introduced by AMC in 1964, when the vast majority of the cars they sold were "three on the tree" manual transmissions and overdrives were a VERY rare and expensive option. Using both my 1966 Rambler American and my brother's 1970 Gremlin as examples, the stock drive train resulted in a speed-to-RPM ratio of 24 MPH per 1,000 RPM. Translation: 2500 RPM was exactly 60 MPH, 3,000 RPM was exactly 72 MPH. That's simply what was. Even with wimpy valve springs and hydraulic lifters the engine redlined at 5,000 RPM, so cruising all day at 3,000 RPM wasn't hurting the engines at all. Today, with 5-speeds (and 6-speeds) with tall gears AND overdrive top gears, you guys see factory cruising speeds of under 2,000 RPM at 70 MPH and you think anything over 2,000 RPM cruise is "burning up the engine." Not so. Now, to put all this in perspective for a modified MJ -- when I did my tire & gear spreadsheet 33s were pretty much the biggest tire most people were looking at, and I stopped at 4.88 gears for the simple reason that's the deepest ratio you can get for a Dana 30 front axle. So ==> 33" tires with 4.88 gears, in 5th gear (or overdrive for an automatic) will run 2620 RPM at 70 MPH. Heck, that's right on the torque peak. That's where you WANT to run the engine for maximum efficiency. Don't worry about going "too far" with gearing. Most likely, you can't. Even 30" tires with 4.88 gears will cruise at 2890 RPM at 70 MPH. That's just about equal to what the AMC factory was putting in as stock gearing for decades.

Another idea (like you need more overload, right?) -- I really REALLY believe you need to extand your patch forward of that body mount. If the idea of notching out the back side of the patch plate to create a recess for the body mount flange won't work for you, there's another way to accomplish more or less the same thing. Run your patch plate a little farther forward than what's in your sketch. Get close to the body mount, but don't make hard contact -- leave room for a weld bead in between. Then put another patch plate onto the side of the "frame" rail forward of the mount. Make this one at least six or preferably eight inches long, and try to cover the full height of the frame rail. Weld around all four sides/edges to ensure that it's sealed to the frame. Now -- take another piece of your patch plate and add a second layer to bridge over the gap where the body mount is. Don't extend this piece to the ends of your original patches -- make it maybe six or eight inches long total, so it extends only a few inches onto the original plates on each side, and falls a few inches short of reaching the outward ends. Be sure (again) to weld all around so the entire perimeter is sealed. You DON'T want moisture and salt to get in behind your patch. Lemme see if I can simulate what we mean by the fish eye ends on the plates. This will be CRUDE: . Straight cut-off (bad): ._____ | | | | | |_____ "Fish eye" (good): . ___________ . / ./ ( .\ . \_________ Best I could do using keyboard characters. Visualize that being more rounded or elliptical at the end (like a football) and you have the idea. The point is to not concentrate all the stresses from the welded seam/joint in a straight, vertical line.

Okay, so which one of you is bi-polar, and which is pregnant?

So how thick is the body mount, and how thick is the steel you're using? If your steel is anywhere near the 1/8th inch you said, you should be able to inlet the back of it so it can pass right over the lower flange of the body mount. At the very least, carry your steel up to within 1/8" or so of the body mount and cope the plate to the same shape. That way your weld can tie into the body mount, too, so you'll have additional thickness to resist burn-through. But I would seriously consider pocketing the plate and running it right over the body mount.

In my opinion the side plating needs to extend considerably farther away from the break, both forward and to the rear. Not nearly long enough the way I'm seeing your sketch. Think "lever arm." The break point is a hinge. The farther away from the hinge you can place the welded ends of the patch plate, the less stress there will be on the welds. I would hope you could extend at least 6 to 8 inches on each side of the break, and if you can get a foot on each side that's even better. Remember, too, that the vertical plates are like the vertical center portion (the web) of a steel I-beam. The web does no work -- it is there only to keep the top and bottom flanges separated. That's why in aircraft and racing cars you see structural members that have holes in the center portions of the structure. That portion isn't doing any work, so it doesn't hurt to remove material to save weight. What that means for your patch is that you can make your plates longer, and then along the mid-height line (the "neutral axis," where the steel isn't in compression or tension" you can cut out a couple of small-ish holes and weld through those as well as at the ends. That provides more complete attachment of the plate to the parent frame. Don't forget to "fish eye" the ends of your plates. Don't cut them off on a vertical line -- make the ends like the nose on a football.

I've heard that one before. So Little Johnny grew up, and became a Marine.

Why are you rushing out to buy a slave cylinder? The way I read the posts in this discussion, you have not determined if the leak is from the master cylinder, the slave cylinder, or the line that connects them. If you checked under the master cylinder from the engine compartment -- that is NOT where they leak. The leak follows the operating rod through the firewall and drips down onto the fuse panel inside the passenger cabin, where it corrodes the contacts for the fuses. That's where you need to check. IMHO, given that the truck is an '86, I think you should do a preemptive strike and replace both. I also suggest buying the parts from a Jeep dealer. For some reason, the experience of other owners has shown that hydraulic clutch parts from any other source typically don't last more than about six months.

Typo alert. Stock Jeep wheel backspacing is 5.25" or 5.5".

They are the same thing. I bought my 2000 XJ as a factory order with Up Country suspension. When it came in, I took the codes off the springs and went to the dealer to order a set of coils to put into my '88 XJ. The parts guy recognized the number -- "Why are you ordering Grand Cherokee springs for a Cherokee?" So he looked, and he confirmed that the standard ZJ V8 coil is the same part number as the XJ 4.0L Up Country coil.

The Mopar perches are longer than stock, although not that much. But if you're using the entire original spring pack, axle wrap is a false concern because with those overload leaves in there, there's NO WAY you're ever going to have axle wrap. IMHO I think the Mopar Performance perches are the way to go. Keep in mind that the Mopar perches are available only cut for a 3" axle tube (which fits the Chryco 8-1/4 axle but is larger than the Dana 44 or Dana 35). However, they can be ground to fit the smaller tubes.

Measuring from the ground is an invalid reference. Center of hub to lower lip of flare completely eliminates variables due to tire size, tire wear, and inflation pressure. 22" for a Metric Ton sounds about right.

Well, speaking only for myself, I want you to do it. Read my signature -- IMHO any MJ that still remotely resembles an MJ is worth trying to save. Remember, they aren't making any more Comanches. There weren't that many to begin with, there's a lot fewer today than there were at the end of 1992, and if we scrap every one that's not rock solid -- well, the ones I have will just become that much more valuable, I guess. Living in a salt-belt climate, I understand the problem. It's easy for some of you to say "forget that one and find a solid one." But pay attention to where freakjeep lives. There probably isn't a solid MJ chassis within 500 miles of where he lives. There's NOTHING wrong with repairing a rusted frame. As I mentioned in the post about my brother's Nissan, there's a shop near me (and near CW) that specializes in precisely this type of repair. Certainly it can be done, but it requires attention to detail if it is to be done correctly and ... most importantly ... safely.

For some reason, the link doesn't work for me. It's live -- I click it and it goes to a new screen with that URL showing in the address window of the browser, but ... no image, no error message, just a blank screen. :???:

The calipers should be the same (although I have heard conflicting reports on this) but you have a conventional spindle and wheel bearings, and the ones with a separate hub/bearing unit do not have a spindle at all. The hub/bearing unit alone costs over $100 (and IMHO it would be foolish to buy a used one because it could fail on you next week), so I don't see much point in trying to make this conversion. To change over, you'll have to pop your ball joints and replace the entire knuckle. Seems like a lot of work when the conventional spindle is probably the better system if you don't have 4WD.

I VERY much doubt that you have 3.07 gears in a 1986 4-cylinder. They should be 4.10s. You have asked multiple times about the stock "power band." "Power band" means the range in which the engine produces the best usable power. The 1986 throttle body injected version produced 117 horsepower at 5,000 RPM and 135 foot-pounds of torque at 3,500 RPM. That means that your power band is from roughly 3,000 to 5,000 RPM. Is that what you were asking?

Then you can't possibly know what you're welding to. The success of your repair is going to depend 90 percent on the preparation. You are not doing yourself any favors trying to "save time" by skipping important steps.

My brother's Nissan pickup was broken that badly a couple or three years ago. He had a shop that specializes in that type of repair fix it. I was hoping I could get some photos, but he said it's parked in and surrounded by mowers and other stuff so getting access to the frame for photos isn't going to happen. Basically, though, the shop plated the frame. The repair was done with the box mounted. Removing it is great if you can do it, but not necessary. But you DO have to wire brush and/or grind all surface rust off before you even think about putting new metal on. What's going to happen is that the holes are going to get a lot bigger, but you need for that to happen so you can see how far you have to extend your plating. The plating has to restore the vertical sides of the frame as well as the bottom. You CANNOT weld to rust. Period. Ain't gonna happen. You MUST be certain that you are welding to solid metal, or your weld is nothing but an illusion. Did you understand the comments about "fish eyes"? That means be aware of stress concentrators. Don't end any piece of plating in a straight line that runs perpendicular to the frame. All you're doing with that is creating a weak spot. Think "football." The ends of all your plates should be oval-shaped on the ends. That distributes the stresses of the welds along a length of the frame rather than on a single line. Do NOT use 1/8" plate. That's much too thick. Ideally, you would use sheet that's approximately the same thickness as the frame you're welding to. That way, both pieces heat up the same and you get equal penetration on both the plate and the parent frame. Somebody mentioned 12-gauge, and that's probably about right. Maybe 10-gauge if you can get it. What's the temperature where you are? Are you working outdoors? You need to preheat the metal before you even start the weld bead. If your father is working with you, one of you should hold a torch and play it along the line you'll be welding to get the metal somewhat up to temperature so there's at least a chance of getting penetration. I am not the world's best welder, but I have taken classes and I have done some welding over the years. I'm afraid I am with the majority on your welds -- you have no penetration. Those are cold welds. Your "beads" are basically lines of slag that's stuck to the surface. I'm sure if you tapped them with a slag hammer the weld beads would break right off. At lest part of the reason is welding to cold metal. I think you're right to worry about burning through the frame metal, but trying to get a balanced weld on two pieces of greatly different thickness, in freezing conditions, is about as bad as it gets. Make life easier -- use similar thickness metal for your plates, and preheat. I am all in favor of saving any MJ possible, and your truck is no worse than my brother's was. BUT ... if you want it to be safe, you'll have to make it safe, and that means spending a lot of time on thinking out how you plan to do the work, prepping the repair areas, and cutting your plates to fit the area to be repaired.