Eagle

^^^ What he said. Exactly.

The 545RFE is the transmission that was in my 1999 Grand Cherokee. Let me put this in perspective: I bought a 1988 Cherokee in January of 1988. Ten years later it had about 175,000 miles on it and I thought it ws getting tired, so I bought a 1999 Grand Cherokee in January of 1999 to replace the 1988 Cherokee. Chrysler bought back the '99 in October to keep me from filing a "lemon law" complaint. I still have the '88 Cherokee. It now has 290,000 miles on it. The 545RFE transmission was one of the major items of complaint I had with the Grand (along with the transfer case and the rear axle, and the front discs warping on a weekly basis). There's just not that much difference between a .75 final drive and a .67 final drive. Run one size larger tires and you've got the equivalent. That transmission is JUNK. (But ... it's from Chrysler, so saying it's junk is rather redundant). The AW4 is infinitely superior.

Why? They are inferior in every way to the AW4. Why would you want to put one in an MJ? Heresy!

DOT 5 is made as brake & clutch fluid. It is completely compatible with DOT 3 and DOT 4 fluids. It won't mix with them, so if you have both fluids in one system they'll be completely stratified and separate, but they'll coexist happily for years. The reason not to do that is, once you put any DOT 3 or DOT 4 in with the silicone, you lose all the non-hygroscopic advantages of the silicone. The U.S. Army has used nothing but DOT 5 silicone for brakes and clutches in military vehicles for something like 25 years. I use only DOT 5 silicone in the brakes and clutch system of my XJs and MJs, and I haven't had any problems whatsoever. I started using it in my race cars about 35 years ago, before I even bought my first XJ. I won't use anything else in a Jeep I intend to keep. The only caveat is that you should NOT use silicone in an ABS system. There are so many different reasons given that I won't even get into it. Chrysler engineers can't tell me why -- they think it comes from the siicone manufacturers. And Dupont engineers can't tell me why -- they think it comes from the car manufacturers. The only thing they agree on is, don't use it in ABS. Fortunately for me, I don't own anything with ABS so it's a non-issue for me, but I have to pass it along when I recommend silicone brake fluid to everyone else.

Nobody mentioned a transfer case drop, except you. Are you asking about MJs in general, or do you know if you'll be working on a longbed or a shortbed chassis?

No, it won't. When the injectors and the ignition fire are controlled by the CPS. The only thing turning the distributor housing does is assure that the rotor is actually aligned with a turret when the ignition fires. That's normally not needed with a stock engine, but some aftermarket cams don't have the distributor drive gear aligned correctly and that makes it necessary to cut off the ears and "index" the distributor housing.

6-cylinder ZJ springs won't change your height at all, and V-8 ZJ springs will give you a 1" to 2" lift. What is it you're trying to do, again?

No, but I can give you the official, factory tech bulletin method of measuring: Top of axle tube to underside of frame rail, straight up. Be sure to measure from the actual tube, not from any brackets or the disconnect housing. 2WD should be 6-3/4" plus or minus 1/2". 4WD should be 7-3/4" plus or minus 1/2".

Trust me ... you don't want to know. When you find shops offering to do it for $100 an axle ... just remember, "You get what you pay for,"

Ummm, 2,788 RPM maybe? Ummm ... maybe. Dang typos ...

No, it's not "ridiculous." It's pretty well accepted Jeep lore. Of course, how valuable your time and effort is to you may be different from how valuable my time and effort are to me. It's a LOT less effort and time to add a pair of perches to an XJ axle (or even to burn or grind off the originals and relocate them) than it is to set up a differential. As to the worth of the results; I'll just post the figures and each reader can make their own decision. These figures were all derived using actual tire manufacturers' revolutions-per-mile from their web sites or sales brochures, so there's nothing theormetical here. And to avoid differences due to the several overdrive ratios used in the XJ and MJ over the years, I'll post only the 4th gear (1:1 ratio) numbers. 3.07 gears / 225/75R15 tires: 26.75 MPH/1,000 RPM 60 MPH = 2241 RPM 3.55 gears / 225/75R15 tires: 23.21 MPH/1,000 RPM 60 MPH = 2584 RPM 3.55 gears / 31x10.50R15 tires: 24.93 MPH/1,000 RPM 60 MPH = 2407 RPM 3.73 gears / 31x10.50R15 tires: 23.65 MPH/1,000 RPM 60 MPH = 2536 RPM 4.10 gears / 31x10.50R15 tires: 21.51 MPH/1,000 RPM 60 MPH = 2788 RPM You want to go through all that work to make a ratio change that's about 15-1/2%. The tires you're running are 6.8% bigger than stock (in terms of actual revolutions per mile, which is what counts), meaning your net improvment for all that work is going to be 8.7%. Maybe that's worth it to you, but having driven and wheeled 31s with 3.73s, there's no way I'd even consider doing 3.55s. Those who have been around here may recall that the reason I ended up with the 3.73s was an accident anyway. I had done the numbers, and I bought the 3.73 gear sets with the intention of installing in my Cherokee to run 30x9.50 tires. Then a Comanche with a 4" lift followed me home. My brother gave me the old 31x10.50s off his Nissan. The MJ had 3.07s, which sucked predictably with the big tires. Rather than buy another set of gears, I just threw the 3.73s into the MJ. They were fine on the street (about like 3.55s and stock tires, as I said above), but not enough gear for wheeling. 4.10s would have been optimum for wheeling, and still very good for street. But ... do what you want to do. It's obvious you didn't come here to ask for advice but to tell us how much you know and how little we know, so ... enjoy the work.

Backlash is only part of the issue -- setting the pinion depth for proper engagement is perhaps even more critical. That's hard to do without the proper measuring equipment, or lots of gear-marking compound and trial-and-error. Second point -- used gears are almost always noisy, because there ain't no way you will ever get them set up exactly the way they were run in before. You may have them set up "correctly," but they won't be the same. Lastly, it's just not worth the effort to go from 3.07s to 3.55s with 31" tires. I ran 31s with 3.73s. The overall final drive ratio works out to exactly the same as 3.55 gears with stock tires. So by going to 3.55s with the 31" tires, about the best you'll manage to do is get back somewhere in the area of stock 3.07 gears and stock tires. You probably won't have much luck finding 3.73s in a junkyard, because that wasn't a common ratio. But most 4-banger XJs and MJs had 4.10s, and that's the optimum ratio for running 31" tires. My humble advice is to not waste any time, effort or money on the 3.55s. Just look for a set of JY axles out of a 4-cylinder XJ or MJ and throw those under your truck.

You wanna explain why you need 450 horsepower for a trail rig -- a vehicle that crawls along at less than 10 MPH at under 1200 RPM 95% of the time? If you want to throw money at an engine, by all means have fun throwing, but IMHO you should at least have some sense of where the project is going. Horsepower in a trail rig is wasted. You can build great trail rigs on the Jeep 2.5L engine. It's only on the highway that engine doesn't measure up.

Chances are your bad alignment screwed the tires up pretty good. Get it aligned, you can try balancing them, but I wouldn't be surprised if you need good ones. Doing the alignment yourself is pretty easy... and free! http://www.4x4xplor.com/alignment.html That is only a toe & steering adjustment...not a complete alignment though ;) Correct. And caster angle is important in solid front axle vehicles. Insufficient caster WILL allow death wobble to show its ugly face.

I don't think you have death wobble. I think you have shimmy caused by tire balance. Let's be clear about what death wobble is. Death wobble is called that because it's SO severe that when it kicks in, you pee your pants and you KNOW you're going to die before you can stop the vehicle. If you had death wobble kick in at 53 MPH, there is no way on God's green earth that yu would or could keep driving through it long enough to get over 67 MPH and have it smoth out. Quite frankly, you would lose control of the vehicle and crash long before you got to 67 MPH. You don't drive through death wobble until it smooths out. The only way to stop death wobble is to stop the vehicle, or nearly stop it (meaning getting down to about 15 MPH or less). Have your tires balanced.

DING! :thumbsup: We have a winnah! No relay for the headlights.

:bowdown: :thumbsup: :clapping:

The dashboard for a Cherokee 1984 - 1996 is the same as a Comanche 1986 - 1992. Unless you're trying to use a 97+ XJ console, there is no need to trim the front of the console when you put it in a Comanche. What do you think -- Jeep made a special console for the Eliminator? :redX:

Can you take a pic from the top of the engine looking down at the hose and PS unit? I have an '86 XJ 4-cyl here and an '88 MJ 4-cyl. Both have power steering. I can probably get you a photo over the weekend for comparison to your setup.

I don't think the YJ ever had the 2.8L. It was either the AMC 2.5L 4-cyl or the 258/4.2L AMC I-6. The Iron Duke was used in some years of the Eagle/Hornet/Concord. Dunno if it ever made it into the CJ.

You would imagine wrong. The purpose of a thermostat is to keep the temperature UP. The way it does that is by closing when the temperature drops below the range for that particular thermostat. Once the coolant temperature rises again, the t-stat opens. If you ran 30 miles at 50 MPH with no thermostat, I doubt your operating temperature would ever get high enough to even put the ECU into closed-loop mode. Yes. There are three possibilities here. The sender is one, and the fact it's new does NOT mean that you can believe it's accurate. Second is the gauge itself. Third is wiring. The temperature gauge in my '88 XJ has been riding just above the first tick mark on the gauge for about five years now (whatever temp that corresponds to). But I have good heat. And my gas gauge and voltmeter have also been reading low, for about the same period of time. I'm fairly certain it's because of corrosion/oxidation where the cluster grounds to the chassis, but I know where they normally run so it's not a big deal. As long as I have a needle that I can see if it's NOT where it normally sits, it's okay. (Not ideal, but "okay.")

It's none of my business, but at this point I think it's time for the guy who did the damage to start doing the repairs -- and paying for them. I learned everything I know about cars, trucks and engines building and repairing (and paying for) my own rides. It taught me that there is a price to be paid if you act irresponsibly, and that breaking it really ISN'T so much fun when (a) you have to pay for fixing it, and (B) you don't have any way to get to work on Monday morning.

If you can hear the blower running, then the blower is working. With the lever set to the HEAT position, no air should come out the dash vents. All air is directed to the feet, through the under-dash outlets. If you expect hot air through the face-of-dash outlets when the control is set for HEAT, you haven't read the owner's manual. The a/c isn't working in my '88, either (low freon, so the compressor won't kick in), so I use the BI-LEVEL setting to get heat to both my feet and through the dash vents. It is possible that you have a vaccum leak in the controls. The flappers that direct air are controlled by vacuum motors. If you have a vacuum leak, their default setting is to push air to the top-of-dash DEFROST outlets. If you can't feel air coming from anywhere else, check there.

I have heard the same complaint about Rusty's hook brackets bending on side pulls, and I would recommend the C4x4 kit if you can't find a set of factory brackets in a junk yard.

Ugh. Mud. Drifting. Overheated -- SIX times. All you've done should have cleared it and shown any residue, but my initial reaction was "hydrolock." That might explain some of the thinning of the oil (was there any evidence of water?), and hydrolock could have cracked the top of one or two pistons, which might account for the variations in compression. I just don't know. And, frankly, I don't recommend that you waste any more time trying to find out. Even ONE overheat is death to an engine. I had a heater (not radiator, just a 5/8" heater) hose burst on my hillclimb car just as I left the starting line. The moron corner workers didn't red flag me or black flag me, they let me run the whole course. So I drove something like 3 miles up a dang mountain, pretty much at redline the whole way, with no coolant. Oddly and miraculously enough, once it cooled down (about a month later) the engine started and ran. It ran like crap, had uniformly low compression, and used about as much oil as gasoline ... but it ran. Clearly, the rings were toast. No point in even investigating ... I just yanked the engine and built a bigger one to replace it. I think I gave the old engine to one of the guys in my car club, and he just threw a set of rings in it and put it into a beater-mobile.