AZJeff

That stuff is Rhino Liner. It was put on at the same time as when the bed of the MJ was done, and was done by a professional shop.

You are quoting some very specific temperatures for the coolant, far more precise than the factory gauges can display. What is your measurement tool to arrive at these values?

I am a big fan of changing the filter whenever I get a "new" car and do a trans fluid change. (The term "new" here means a older vehicle that has had unknown maintenance.) So my approach is to change the fluid AND the filter the first time, and inspect the filter (and the bottom of the pan) for any abnormal signs. Assuming nothing is found, all subsequent trans fluid changes are just the fluid, and I leave the filter alone. I am also a big proponent of changing the fluid more often than officially recommended. On my all my vehicles, I change fluid every 24K miles, but I don't tow any thing with my vehicles.

Interesting. Thanks.

Something is awry with what you have said about your MJ and its' cooling system performance. I have PLENTY of experience with MJ's and XJ's being operated under FAR more strenuous conditions that yours. (I live in the PHX metro area, and temperatures above 105* is a daily occurence here, and I run my AC all the time.) An MJ/XJ with the 4.0 is going to run what might seem to be hot, but it's within the design limits, assuming that all components of your vehicle are up to OEM standard. (That means radiator, fans/shrouds, hoses, radiator pressure cap, 50/50 coolant mix, and thermostat.) WIth all of these things up to snuff, it's normal to see (in my climate, at least) the engine run right about 205*, with a tolerance of =/- 10 degrees. If you think this is too hot, your expectations are incorrect. (I assume you have confirmed your temperatures by using an infrared thermometer measuring the temperature of the thermostat elbow on the engine.) The transmission in your vehicle should never exceed 200* for any more than a minute or two at most. If it's seeing more than that, an aftermarket fluid-to-air heat exchanger is needed. (And the trans may need investigating) There is no doubt that altitude WILL reduce the effect of cooling across the radiator, as (for example) the air is only 81% as dense at 7000 feet as it is a sea level. However, this is offset by the fact that you are probably NOT running air conditioning in your MJ at 7000 feet, so the temperature of air entering the radiator is not being increased by heat being shed from the condenser.

What is a “knuckle pod” light?

Somehow, the original write-up I created for this forum does not exist on my computer any more. Chalk that up to some sort of screw-up on my part, since I normally keep good records. It also looks like the PDF that was posted to the forum originally is missing/corrupt. The only thing I could do was to capture screen shots of the write up off of this forum, and some clarity of text/images was lost doing that. I have those assembled into a PDF, which I have attached. Sorry, this is the best I could do. 601007367_MJTaillightRennovation.pdf

More likely is the “park” switch in the wiper motor transmission is stuck in the “permanently on” position. you might be able to fix it by removing/disassembling the wiper motor to clean/repair the park switch, or replace the whole wiper motor/trans assembly.

It sounds fairly normal to me, but it's a bit hard to tell for sure, because I hear several different rhythmic noises in your two video clips. You can help pinpoint the source of the noise by using a mechanics stethoscopic and probing around various parts of the engine. If you lack the stethoscope, then a section of wooden dowel rod, or a long screwdriver, can substitute.; The 4.0 is not a quiet engine, but most of it's sounds should be steady and rhythmic. Trying to make it as quiet as some newer engines is pretty much impossible.

THIS, TIMES ONE MILLION. The BEST bit of advice given above is to get a REAL service manual for your model year, if you do not have one already. Chasing wiring issues without the manual and it's critical wiring diagrams is like trying to drive in a strange place without a road map (pre-GPS days). If you are not familiar with, and own, a multimeter to measure continuity and voltage, go on line and learn how to use one, and then go buy something that does the basic measurements. Automotive wiring of the era of the MJ does not require a fancy multimeter. Even the old "moving needle" type that Radio Shack used to sell will do the job, so the dollar investment isn't large.

The "leading" shoe of a drum brake system (the one towards the front of the vehicle) is ALWAYS smaller than the "trailing" shoe. What you found is perfectly normal. When I studied brake systems in college as part of my mechanical engr. degree, we were taught that drums brakes are designed to be "self energizing," meaning that once the shoe contacts the drum, the frictional forces tend to actual encourage the shoe to pull tightly agains the drum surface, and maintain the frictional bond. If and when you install new shoes, make sure that the shoe with the smaller/shorter arc of friction material in located on the FRONT side of the assembly. BTW, based on the one photo you provided, your brake hardware (springs, brackets, etc.) look pretty decent. A new set of shoes, and a properly turned (or replaced) brake drum will restore your service brakes to original condition. If your parking brake is non functional, you will need to replace the cables, etc. regardless of whether you restore your drum brake system or replace it with the disc setup off an Liberty or similar.

That's true, Pete. However, he still needs to get all the hardware off the end of the axle to do any rebuild or upgrade of the rear brakes.

That is very similar to the "Ziebart" undercoating that my dad put on his cars back in the 1960's and 1970's when I lived in Illinois. It works pretty well INSIDE a hollow, boxed compartment. It tends to be abraided off an external surface that gets water, salt, sand, dirt, etc. thrown up on it. Because of that, it needs to be reapplied every couple of years.

The only thing that holds the top part of the shoe to the backing plate is going to be a sort of "diamond shaped" retaining plate that is slipped over the top of the upper shoe anchor stud on the backing plate. That retaining plate is, in turn, captured on the anchor stud by the upper shoe return springs. There is no way to get those upper return springs off with the drum in place. Here is my suggestion: There is a shoe retaining stud/spring assembly that holds the shoe to the backing plate. The head end of this stud pokes out through a hole in the backing plate. If you can cut/grind or otherwise break the head of the stud off the back side of the backing plate, then the shoe (and the drum) can move further out (with prying) and then maybe you can start taking the adjuster assembly out through the gap between the bottom of the drum and the backing plate. Once the adjuster is out, the shoes can collapse inward further, and make getting the drum off easier.

I second this, after dealing with rust on many vehicles over the years. The hollow compartments in the chassis of the MJ (such as the rocker panels) have dust/road dirt seep in slowly over time (they are not airtight). Then, moisture from rain (and salt water in areas that use salt on the roads) also seeps in, and the dust absorbs this moisture, creating "mud" that holds the water/salt against the steel. That's the perfect way to get corrosion going. The secret is to: (1) make sure all hollow compartments are free to drain of dust/dirt/water as much as possible. The designers do provide SOME drain holes, but the often are too small to do a good job. (2) flush the boxed compartments as best as you can with fresh clean water to drive out the dust/dirt/salt, etc. (3) consider using some sort of protective coating in the hollow boxed compartments if you live in an area where moisture/salt is present during a large portion of the seasons.

Is that with or without a gasket?

My AW-4 transmission pan started leaking recently, so I put on a new Fel-Pro gasket and used black Permatex RTV gasket sealer on both sides of the gasket. I torqued the gasket bolts using my calibrated "wrist tight" method that I have used for the past 40+ years of working on vehicles. I am confident I did not overtorque them, and the gasket does not look distorted around the bolt holes. None the less.....the leak is still present, but it is lessened. My questions are: 1. can the pan be installed without a gasket, and just use the appropriate gasket making compound directly on the pan flange, like what is done on differential covers nowadays? 2. if a gasket is needed who makes the best gasket for this application? (I alway have felt that Fel-Pro was good to go for most gaskets.)

That is true. At one time, (before the advent of very consistent machine tools) it was not unheard of for an engine to have oversized cylinder bores as well as undersized bearings straight from the factory. During that time, fully assembled engine blocks would be stamped with a series of coded letters/numbers to indicate what features are over/undersized, and the factory would supply dealers with the way to decode those added markings. It's pretty rare to see that today. I was surprised when my 2000XJ engine in my MJ came with 0.001 undersized mains, but standard sized rod bearings as new.

You are correct about there being 0.001 undersized rod bearings being available from Rock Auto, but only Sealed Power brand. It’s odd the local Jeep dealer here did not list that part, but only the mains…

To the best of my knowledge, the factory on used 0.001 undersized bearings on the mains only. The rods were always standard. At least that is what I found when searching for new bearing shells for my engine. The dealer listed a 0.001 undersize for mains, but nothing for rods.

Clevite is my choice from Rock Auto. Rod bearings only come in sizes where the journals are standard size, or 10, 20, or 30 thousandths undersized. I cannot imagine a journal wearing 0.010” undersized evenly by itself. The only way it can get that way (and be even) is by being machined undersized. FWIW….

Trivia bit: most of AMC's radiators were made by Blackstone Corp. in Jamestown, NY. The company founder sold the business to some Swedish outfit in 1984. They still manufacture radiators for large trucks, and, since they are Swedish, they have a factory over in Europe that supplies radiators to Volvo.

Yeah, but what is it when idling in traffic this afternoon on the way home, when it's 107*?

Factory spec. for a 4.0 is 13psi minimum at hot idle, and 37psi minimum above 1600 rpm. (This assumes using the recommended 10w30 or 10w40 oil.) Here in AZ, in the summer, the oil pressure on the 4.0's I have owned isn't really very high when the engine is REAL hot, generally being about 40 psi at road speeds. (Underhood and pavement temperatures in Phoenix are something everyone should experience to see how oil pressure drops down as the engine heats.

Putting recycling codes on polymer parts wasn't a common practice when the MJ's were in production, so it's not too surprising to see forum members reporting not finding such identifiers on interior parts. Based on my years of experience with resins when I earned a living as a mechanical engineer, I think that most of the pieces of the interior of an MJ are ABS. (Newer vehicles use ABS/polycarbonate blends for these applications, but the MJ predates that use.) ABS can be repaired by solvent welding and also with some of the filler resins out there pretty sucessfully. The kick panels and similar stuff are probably polypropylene, which is more flexible and has an almost "waxy" feel to it. Polyprop is much trickier to get welding to work successfully.