Eagle

Maybe this will help:

Why would you need a rear main seal to do a 4x4 conversion? The rear main seal is inside the engine and you have to drop the oil pan to replace it. Swapping the transmission doesn't in any way affect the RMS.

The Jeep ignition is already a high energy system. Buying an aftermarket coil is just a waste of money.

Here's the rundown yet again: In general, the parts to be concerned with in keeping the front brakes compatible are the steering knuckles, the hub/bearing assemblies, the rotors, and the calipers. (There is a more complete enumeration of the interrelationship of these parts in Chapter 6, Axles.) • Only two steering knuckle designs were used: 1984 through 1989, and 1990 through 2001. Left and right side knuckles are different part numbers within each group. • Three different hub/bearing units were used. The hub/bearing units are the same for both sides of the vehicle. The different years for hub/bearing assemblies were: 1984 through 1989; 1990 through mid-1999 (composite rotors); and late-1999 through 2001 (cast rotors). • Three rotor types were used: 1984 through 1989; 1990 through mid-1999 (composite); and late-1999 through 2001 (cast). • Only two caliper types were used: 1984 through 1989, and 1990 through 2001. Left and right side calipers are different part numbers within each group. Basically, you have to keep all the parts from within a compatible group of years. The hubs have different offsets from the mounting flange to the outer surface. As I note every time I post this, it's from the manuscript of my unpublished book. It is copyrighted, and by posting it here I am NOT granting anyone permission to reproduce it or redistribute it. Please respect my copyright.

IMHO you're looking at a bad idea. The MJs (even the short beds) have a longer overhang behind the rear axle than the XJ, which increases the exposure of the gas tank to getting whacked. You could, theoretically, hang an XJ tank behind the axle of an MJ, but you would lose the spare tire location, and you would have to custom fabricate hangers. Also, what are you going to do for a fill location? What brand skid do you have? The factory XJ gas tank skid didn't attach to the bumper, it attaches to the unibody frame rails.

Tire balance is the solution.

The junkyard box I put into the '01 is 3 turns lock-to-lock. The '88 XJ, the MJs, and the '00 XJs are all 3-1/2 turns. That tells me the junkyard box is 12.7:1 ratio.

Depending on what the OP is accustomed to driving, it may just be the amount of boost that's fooling him. AMC was always famous/infamous/notorious for using too much boost in their power steering, resulting in zero road feel. Chrysler eventually corrected that in the XJs, but I don't know when. I can tell you that, although my 1988 XJ and my 2000 XJ both have power steering and both have 14:1 boxes, the steering "feel" is completely different. As different as night and day.

I've given you something concrete. The factory service manuals from 1986 through 2001 ALL say fixed ratio steering box. The factory parts manuals list variable ratios only for models other than the XJ and MJ, and then mostly for export only. I don't know about you, but I'll trust the factory before I'll trust something I found on the Internet.

Variable ratio is not impossible with a tradition worm-and-sector steering box. Generous Motors had them back in the early 70s. My mother had a 1970 AMC wagon with a Saginaw variable ratio box. The theory behind it is that when the wheels are straight, X amount of lateral movement of the drag link results in Y degrees of wheel turn. However, due to geometry, as the wheels move farther off center, that same X amount of lateral movement in the drag link and tie rod doesn't generate as much angular displacement of the road wheels. So they came up with variable ration boxes as a way to (supposedly) make the steering more uniform. Personally, I hated it. The ratio varied from about 17:1 at the center to around 13:1 at full lock. It was too slow to react at highway speeds, making evasive maneuvers less effective. I much prefer fixed ratio. That's what I've been driving for 60 years, so I guess I'm sort of set in my ways. Back to the reason for this post: Not only is variable ratio possible in a standard Saginaw steering box ... they exist.

Agreed. The first number in an oil designation is the cold viscosity, the second number is the operating temperature viscosity. So a 5W50 is thin like a 5-weight when cold, but still has the viscosity of a 50-weight when hot. Like Noriyori, I run 5W50 (I use Castrol Syntec) in the high mileage engines to compensate for loss of oil pressure due to worn bearings.

As I commented above, the 1988 FSM shows an optional 17:1 fixed ratio power steering box that was included in the off-road package. I don't know what year that option was discontinued. The 1994 FSM shows power steering boxes in 14:1 and 12.7:1 fixed ratios, plus a 13-17:1 variable ratio. BUT ... the 1994 FSM covers more vehicles than just the XJ, and the book doesn't tell which vehicles or models were equipped with which box. There are 2-letter codes for each, stamped into the top of the box. My guess would be that the short wheelbase Wrangler got the variable ratio, so the steering wouldn't be as "twitchy" over center on the highway. The 2000 XJ FSM shows only the 14:1 fixed ratio box. {EDIT TO ADD} I did a bit of research through the parts manuals. Let's just say that it's a bit more complicated than "There's only one box for all the years." 1988-1990 XJ/MJ parts manual: XJ/MJ Part No. 5200 2737 1991-1993 parts manual: . . . XJ/MJ Part No. 5203 8002 . . . . . . . . . . . . . . . . . . . . . . . . .ZJ . .Part No. 5208 7753 or . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5208 7754 . . . . . . . . . . . . . . . . . . . . . . . . .YJ . .Part No. 5203 8003 1994-1996 parts manual: . . . . YJ . .Part No. 5203 8003 . . . . . . . . . . . . . . . . . . . . . . . . .XJ . . . . . . . . 5203 8002 ... '94 . . . . . . . . . . . . . . . . . . . . . . . . .XJ . . . . . . . . 5203 8408 ... '95 . . . . . . . . . . . . . . . . . . . . . . . . .XJ . . . . . . . . 5208 8015 ... '96 . . . . . . . . . . . . . . . . . . . . . . . . .ZJ . . . . . . . . 4 different boxes listed, depending on options 1997-1999 parts manual: . . . . XJ . . . . . . . . 5208 8386 ... '97 . . . . . . . . . . . . . . . . . . . . . . . . .XJ . . . . . . . . 52088 386AB ... '98 . . . . . . . . . . . . . . . . . . . . . . . . .XJ . . . . . . . . 5208 8532 ... '98 . . . . . . . . . . . . . . . . . . . . . . . . .XJ . . . . . . . . 52088 386AD ... '99 . . . . . . . . . . . . . . . . . . . . . . . . .XJ . . . . . . . . 52088 532AH ... '99 2000 XJ Parts Manual: . . . . . . XJ . .Part No. 52088 386AC 2001 XJ Parts Manual: . . . . . . XJ . .Part No. 52088 386AC No ratios listed, other than a couple in the export listings (which I didn't try to reproduce)

For 1988 the factory recommendation was 10W30 or 10W40. When my '88 was new I ran 10W30 in the winter and 10W40 in the summer. It does not sound like your engine was "rebuilt. There's a lot more to a rebuild than replacing gaskets -- like bearings, rings, valve job, etc. So basically you have 118,000 miles on the engine. AND ... remember that the 2.5L has more gear, so for every mile you drive, the engine spins around more times than a 4.0L would. You have a 5-speed, so your gears are 4.10s. My '88 4.0L 5-speed has 3.07 gears. In round numbers, your engine goes around 4 times for every 3 times mine goes around. So, since most of us use the 4.0L as the frame of reference, your rings and bearings have seen the equivalent of 157,000 miles. I think you should be running 10W40 as a minimum. If it were mine, I'd be running 20W50 for the summer, 10W40 for the winter. New London must be in a micro climate. I'm outside New Haven -- we had several nights this past winter that were -10 without factoring "wind chill."

I got it from the factory service manual. I checked the 1988, 1994, and 2000 FSMs. [Note that the very early XJs had a 17:1 fixed (not variable) option as part of the off-road package. I've never encountered one -- ever.] The only way for me to "show" you would be to scan or photograph the page, upload it to Photobucket, and then post a link to the image. I don't have time for that. You can either accept my word that's what it says ... or not.

Just to be clear -- you are "all right," but you're not "fine." Your idle pressure is below spec. That's to be expected on an old, probably high mileage engine, but the reason we expect it is that we expect moving parts to wear. While the minimum idle oil pressure is 13 psi, most healthy Jeep engines idle at around 20 to 25 psi. So you have some early warning signs -- IMHO you should start considering either dropping the pan and replacing the main bearings (or all the bearings, while you're in there), or start looking for a spare engine you can rebuild while the one you have still runs. As others have commented, oil weight also matters. When my '88 went over 200,000 miles and the oil pressure started reading a bit lower than what it had been, I switched to Mobil-1 full synthetic in 15W50 weight, then I went over to Castrol 5W50. My oil pressure in the '88 still isn't where it was when new, but I'm now at 287,000 miles and I'm still within factory specs.

The stock XJ/MJ box is 14:1, fixed ratio. 3-1/2 turns lock-to-lock.

But we're talking about a 1988 Jeep, not a 2014 Chevy. The Chevy might have a different type of pump. I cited the factory service manual spec for oil pressure. If you don't believe me, look it up for yourself.

I agree. The '01 steering box had been trashed by a previous owner and couldn't be adjusted, so I had to replace it anyway. If I had it to do over, I'd go to AGR Steering and buy a 10:1 box. (Which would NOT be good for large tires and rock crawling.)

Your pressure is basically fine, for a 28-year old engine. Factory spec is 13 psi minimum at idle, 37 to 75 psi above 1600 RPM (at operating temperature). So your warm idle is a touch below spec, but not unreasonable. It's the pressure while driiving that's of more concern. The faster the engine turns, the more oil pressure it generates. For NEW engines, around 50 to 55 psi at 60 to 65 MPH seems to be about the norm. 40 psi on the highway is lower than what we expect from a new engine, but you don't have a new engine.

The factory XJ and MJ box is 14:1 and 3-1/2 turns lock-to-lock. The 12.7:1 ZJ box is 3 turns lock-to-lock. I have a ZJ box in the 2001 XJ, and the factory box in my wife's 2000 XJ. The only time/place I notice any difference is when backing up and turning 90 degrees in the driveway. On the road I don't notice any difference whatsoever.

It's only a spacer. What's wrong with the factory unit?

The usual cause of this is a vacuum leak in the line beneath the battery tray, to the vacuum reservoir "blimp" that's mounted behind the bumper on the passenger side.

I agree completely. Driving an XJ or MJ without the sway bar is dangerous even at stock height. With a lift it's considerably more dangerous.

No. The Renix XJs and MJs have the throttle cable running to a bellcrank mounted on the driver's side frame stub ear. From the bellcrank, IIRC, there's a rigid rod that extends up to actuate the throttle body butterfly.

It also won't have any effect on bump steer.