Eagle

The Alldata article should just confirm what I already posted. The actual factory TSB had a line art picture of the cap with the "window" cut in the side, but the procedure is the same. The key is to use the timing marks on the front cover to ensure that the crank is at exactly TDC -- and, of course, to be certain you're on the compression stroke and not the exhaust stroke.

What do you mean by "fit"? Physically, the 4.0L engine is the same block right up to the end of Cherokee production in 2001, and another year or two in the Wrangler. But if you want to just drop in another engine and keep your existing computer and wiring -- 1990 was the last year for the Renix injection/ignition system that's in your '88. Chrysler switched over to a completely different, ODB-I compliant system in 1991 that ran through 1996. 1997 was a sort of hybrid, mostly ODB-II compliant system, and then in 1998 they brought in a totally different system in the Cherokee that was used up until the end.

Gracias, Chico

You need to revise your signature, then, if you're still working on the lift. It's no fair claiming future mods in your sig. Heck, if we get to claim mods that are still laying around the garage or the basement, Pete would run out of bandwidth on my list of "Someday maybe I'll get to almost installing these" type mods.

You're certain you were at TDC on the compression stroke, and not the exhaust stroke? There was a TSB out on a timing correction for the Renix 4.0L engines. Apparently some of them must have had either a bad drive gear or the gear on some aftermarket camshafts was out of spec, causing the timing to be slightly off. The fix was to grind the locating ears off the distributor so it could be manually adjusted. Then it was set so that the rotor was NOT pointed exactly at the #1 contact in the cap, but slightly after it. If anyone has access to Alldata, we're looking for TSB #18-53-88. I remember that setting it involved taking an old distributor cap and cutting away the side around the #1 terminal. Then you use a feeler gauge to check the clearance between the tip of the rotor and the #1 contact on the cap. The clearance is supposed to be 0.020 when the #1 pistol is EXACTLY set at TDC. The rotor is supposed to be on the "departing" side of the #1 contact in the cap. In other words, there should be a gap of 0.020" between the cap contact and the trailing tip of the rotor contact. Be sure the #1 piston is at exactly TDC when you check this, and be sure #1 is on the compression stroke, not the exhaust stroke. Believe it or not, the 4.0L engines still have a set of timing marks on the front cover, and the harmonic balancer still has an index line. Use that to set #1 at exactly TDC, don't rely on eye-balling it.

If you disassemble the tee and run from that to the rear hose, you end up with not one but TWO connected lines running the full length of the chassis. Either one could rust through, so you're doubling the probability of losing your rear brakes. The original poster lives in the rust belt. MJ brake hard lines very often rust out and fail just in the vicinity of the fuel tank. Since he wants to eliminate the height sensing proportioning valve anyway, it makes much better sense to replace both rusty old hard lines with one new line and not drive around wondering when your right foot is going to go to the floor at a stop light.

The timing is not adjustable. Just exactly how did this genius determine that the timing was wrong? One tooth on the distributor drive gear is a bit more than "a hair."

^^^ I was also going to suggest pieces cut from Cherokee doors. They should be easy to find. If you need a long piece, look for a 2-door XJ, they had longer doors.

^^^ He said it much better than I could have. The bottom line is -- until you are 18 years of age, your parents are legally responsible for you and your actions. Their house = their rules. You have already had four suspensions THIS year? The school year is only 2/3 finished. You have to really work to get four suspensions in less than one school year. To you, the punishment may sound extreme. To me, who somehow managed to make it through four years of high school without a single detention, let alone suspension, it sounds to me like you don't have much respect for rules, and perhaps your parents think you need some help in coming to grips with that. I agree that many rules in high school are stupid. When you get out of school, you'll find that many of the laws in society are stupid. But they are the laws, and we break them at our own risk. Those who continually try to justify breaking laws because the laws are stupid usually end up with prison records and a lot less cash in their pockets than they might otherwise have. All actions have consequences. I think your parents are trying to teach you that.

Something like a Lock Rite is the cheapest way to lock a Dana 35, but that isn't a limited slip -- it's a locker. If you want a limited slip, the cheapest way is to buy a Dana Trac-Lok unit and install it. I haven't priced them for awhile, but I think they run about $225 to $250. If you're not changing gear ratios, you won't have to reset the pinion depth, so all you need to worry about is matching the ring gear backlash. The idea of the Exploder 8.8 is a good one, if you can buy it for the right price out of a junkyard. Keep in mind, though, that the 8,8 doesn't work with stock Jeep tires and wheels. The Exploder axle is slightly narrower than the MJ axle, so you need to run rims with less backspacing, or spacers (which are expensive) to keep the tires away from the inner fenders. Unless you plan to beat on it, I'd go with the Trac-Lok. I'm sure that's a minority view, however.

Best way is to run a totally new hard line from the front metering block directly to the rear axle brake hose. The old lines are probably rusted and weak anyway, so get rid of them. The new line should come off the outlet in the "nose" of the metering block. The other outlet, the one on the underside and toward the front of the valve, is the outlet for the height-sensing valve bypass. If you run straight from the "nose" outlet to the rear brakes, the other outlet in the metering block should be plugged. You can do that by taking a standard fine-thread bolt (I don't remember what size, I think it's either 5/16" or 3/8" ), cutting it to about 1/4" in length, and putting an o-ring on the shank before screwing it into the hole.

Just for laughs -- jack it up, remove the inspection cover from the bottom of the bell housing where it mates up to the block, and check the four bolts that hold the torque converter to the flex plate. Those bolts sometimes back out and cause symptoms that tend to defy diagnosis. The bolts are accessible through that inspection cover.

aemsee is correct. You are perhaps confused because AMC did buy GM "iron duke" engines for a few years. But those were used in Eagles and Concords, they were never used in the Cherokee/Comanche. The Jeep 2.5L engine is based on the Jeep 6-cylinder engine, it is not based on or developed from the GM engine in any way. Good luck trying to use Iron Duke parts in a Jeep engine. I hope you have deep pockets ...

The description of the shifter choices does NOT sound like the 242. Are you certain it's an '87? Is there just a shift lever for the transfer case, or is there also a knob or botton on the console and/or a horizontal sliding lever that moves across the vehicle, widthwise? Is there a "Power/Comforst" switch on the dashboard, in the toggle switch block to the right of the steering column?

The Mpoar Performance Catalog offers two or three different cam kits for the 2.5L Jeep engine. I think they are still available. I'd look for a Stage 2, but a Stage 3 would probably still be streetable.

The Performance Catalog isn't in print, but it is still available on-line. And most of those parts are still available through Mopar dealers. They all have access to all the Performance Catalog parts, so you don't have to go to a Jeep dealer if you have a relationship with, for example, a Dodge dealer.

Nobody fully understands death wobble, but CW is right -- bad shocks cannot cause it. And REAR shocks don't even enter into consideration if the problem is "death wobble," which ends up with the front wheels oscillating so violently that you literally can't steer the vehicle, and have to pull over and slow down to 20 MPH to get it stopped. If you aren't peeing in your drawers and seeing your life flash in front of you, it probably isn't "death wobble." Assuming that it is, what's happening is that one front wheel starts to shake, and then due to harmonics the shake gets transferred to the other front wheel. After that, the shake in each wheel reinforces the shake in the opposite wheel, with the result that the amplitude of the shaking is constantly increasing. The usual cause is either wheel balance, or an out-of-round tire/rim. Those are really the only things that can start the process (well, a badly warped rotor on one side is a remote possibility, as well). However, once one wheel starts shaking, things like sloppy track bar bushings or worn-out shocks can allow the harmonic transfer to the opposite wheel more easily than if everything was in good condition. If you are just rolling down a fairly smooth road and the shake sets in at 45 MPH (or 50, is more usual in my experience) without hitting any bumps or potholes -- get your tires balanced. If it still happens, take the tires back and make the shop re-do it. The bigger the tire, the more critical tire balance becomes. There are a LOT of shops out there that have a fancy machine, but they hire some doofus at minimum wage to run it, and the usual attitude is "That's close enough." "Close enough" usually isn't close enough.

Stroking the 2.5L is one of those things best undertaken only by those with a lot of time and money. There is no easy way to do it. The 4.0L stroker is easy because the block is the same basic layout as several other, older engines in the AMC line, so the 4.2L (258 cubic inch) crankshaft is a drop-in fit and provides an instant and inexpensive source for the heart of a longer stroke engine. The 2.5L engine is built on the same basic engine design, but it is the only displacement Jeep ever built as a 4-cylinder. That means there's no other engine that can be used as a source for a cheap stroker crankshaft. Messing around with offset-ground journals is expensive, and each attempt becomes a one-off prototype. IMHO, the best way to get more power out of the 2.5L is a camshaft. The factory cam has the same specs as the 4.0L engines of the same years, which makes them very mild for a smaller displacement, higher-revving engine. A slightly more aggressive cam will really wake up the 2.5L and it's a lot cheaper than trying to stroke it.

Yes, there's a difference. A limited slip is a limited slip. It isn't a locker. Put too much torque to it and the clutches slip. It also wears out, and the clutches require a special additive for the gear oil. You could transfer a Trac-Lok from one axle to another, but you would have to know enough about setting up gears to be able to measure the lash on your original setup and then match it exactly with the Trac-Lok. If you don't match the existing gear pattern, you'll have a noisy diff and possible early failure.

I think some clarification is called for, because you are mixing up terms. As CWlongshot already noted, "posi" was short for "Positraction," which actually a GM trade name for their limited slip differential. Over the years, "posi" was sort of hijacked to refer to any limited slip differential. But, whether you call it a "posi," a "Trac-Lok," or any of a variety of other trade names, it is a limited slip differential, it is not a "locker." Jeep did offer a limited slip in both the Cherokee and the Comanche. It was a Dana-Spicer unit which both Jeep and Dana called Trac-Lok. Jeep never offered a true locker until the air locker they put in the Wrangler Rubicon a few years back ... and they put that unit ONLY in the Wrangler Rubicon. Your parts truck could have a Trac-Lok even if it's a Dana 35. The usual test is to jack up one rear wheel, with the parking brake off and the tranny in neutral, and see if you can spin the wheel by hand. If it doesn't spin, you have Trac-Lok. The catch-22 is that if the wheel does spin, it doesn't completely prove that the diff doesn't have Trac-Lok. The system uses clutches, and they usually last only 75,000 to 100,000 miles. Once they wear out, the diff acts like a normal, open differential. So the only positive way to know if there's a Trac-Lok in there is to remove the diff cover and look.

Got a better description of the symptoms? Does "cuts off" mean the ignition stops firing completely? If it cuts off when your foot is off the gas, does it cut back on when you step on the gas?

Bummer, man. I've lost a few dogs in my life, and it never got any easier. I'm sorry you had to go through it.

My guess would be "yes." I only buy CPSs from the dealer. It's too critical to take chances on saving a couple of bucks on a part that should last over 100,000 miles, but can leave you thoroughly up the creek without a paddle when it decides to not work.

Hey, comanchedude - I'll take care of my posts, you take care of yours. Quaker State oil is crap, and it does leave a gunky, varnish-like build-up inside the engine. If you want to believe that's not paraffin, it's your money and your engine. I won't let the stuff near anything I own. 30 years ago Quaker State was the only oil I ran if I couldn't find Amalie. The stuff they sell today is not at all like the stuff they sold 30 years ago. Back to the question of what to run: for an older, high-mileage engine, I think 10W30 is a bit light. I always ran 10W40 in mine, even when new. Around 200,000 miles I changed to 20W50. Then I switched to full synthetic and I've been running Castrol Syntec 5W50 (when I can find it) because the 5 weight when cold provides better start-up flow in cold weather. I'm not as worried about that in summer, so if I can't find 5W50 I'll run 20W50.

It is throttle body injection. But the difference is not semantic. A carburetor works on the principle of suction. The high velocity of the air stream as it passes through the carburetor venturi (or venturis, if it's a 2-bbl or 4-bbl) creates a low pressure, which sucks fuel out of the carburetor float bowl(s) through the jets. The fuel pump works at approximately 7 psi, and all it does is pump the gas up to the float bowls. The gas is not pumped from the bowl(s) to the venturis -- it is sucked by vacuum. Throttle body injection is just the opposite. The fuel pump sends gas directly to the injector(s) under relatively high pressure, and when the injector(s) fire(s) the gas is squirted into the air stream under pressure, rather than being sucked in by vacuum in a carburetor. The difference is very much not semantic. It's a fundamental difference in the mode of operation.