Eagle

Then how about just an RV cam? Similar lift to stock (maybe even a bit more), but shorter duration and less overlap will generate more dynamic compression.

The 231 (Command-Trac) transfer case locks the front and rear driveshafts. That's why it's not supposed to be driven on pavement in 4WD. The fact that the two driveshafts turn together is NOT a sign of a problem, it's a sign that the transfer case is in 4WD. If you can scare up an assistant, jack up both rear wheels again. Have your assistant rotate a rear wheel back and forth, as far as it will go in each direction, while you try to shift into 2WD. This may relieve some internal stress and allow it to shift.

Now that you've mentioned "stroker," the big hurdle when trying to do a budget stroker is that minor differences between the 4.0L and 4.2L engines add up, and you get an engine with too high compression for street gasoline -- unless you're VERY careful about things like quench height, timing, and probably enlarging the combustion chambers a bit. So a budget stroker might be a natural for LPG. But I don't think that qualifies as either fast or easy.

I suppose it depends on your definitions for "fast" and "easy." The two ways I can think of are either installing new pistons, or decking the head.

Not right. See if one of your doors has been replaced. There should be a tag on the drivers door -- the VIN and paint codes should match your vehicle.

The Base models (or SporTruck, in some years) did not include a passenger side mirror, and the driver's side was the silly "flag" style mirror mounted on the door rather than the typical XJ style mirror that mounts to the front corner of the vent window frame.

Put a jack under the rear axle and lift both rear wheels off the ground to relax any stress on the drive line, then try shifting.

"If it ain't broke, don't fix it." My '88 XJ 4.0L is at 287,000 miles on the original lifters, rockers, and pivot balls. You have less than half that. If you're rich and enjoy wasting money, go ahead and replace everything, but the notion of doing unnecessary work to something you don't need to touch "just because I'm working nearby" doesn't make any sense at all to me. Just replace the guide seals and do the head gasket.

I found where he's talking about it. Does he do a write up on it? Sent from my HTC One M9 using Tapatalk Not that I can recall, but I think he's still alive and out there on the Internet with a blog. You might be able to contact him. If not, it should be easy enough to dope out the switch sequence. My guess would be that the last position is 4th with torque converter lockup. I imagine you would still need a shifter handle of some sort to go from park to reverse to neutral to drive, and the rotary switch just handles the transitions in drive.

The Mopar shades were made by Vent-Shade. They were the same exact product.

My first thought was a loose exhaust manifold bolt.

Then I would either rebuild the original engine to stock specs, or take the XJ engine, replace the main and rod bearings, and drop that in. The idea of a stroker engine is attractive, but it can't be done on the cheap. There are subtle differences between the 4.0L and 4.2L engines. You obviously can't use stock 4.0L pistons with a 4.2L crank, so you have to decide if you want to use the skinnier 4.2L connecting rods or the stronger 4.0L connecting rods, then you have to source pistons that will work with whatever rods you choose to get the right deck height. There may be aftermarket pistons available today that will work, but when I looked into it a number of years ago the available combinations resulted in overly high compression ratio, which meant running premium-grade gas AND having to be very careful about "quench." For me it wasn't worth it.

The 4.0 The 4.0L engine isn't overhead cam, so the front cover doesn't come off to change the head gasket. There is absolutely no need or reason to mess with the timing chain, water pump, or harmonic balancer just to do a head gasket. Valve lifters and cam lobes become work hardened from use. Replacing lifters without replacing the cam at the same time is very risky, and probably means the new lifters won't last very long. 138,000 miles is nothing to a 4.0L Jeep engine. I would just pull the head, maybe clean out any carbon on the combustion chambers, and reassemble. To do it right, you should have the head checked for flatness by a machine shop, and resurfaced if it's not flat. To do that, you'll need to remove the valves and valve train. Be sure to keep the valves, lifters, rockers, and pushrods organized so that everything goes back exactly where it came from. On my '88 XJ, I decided the replace the timing chain at 200,000 miles as a preventive measure, because I remembered that older AMC engines used timing chains with nylon sprockets. Got it open to find that everything was all steel, and there was no evidence of wear, slack, or slop in the chain. I put the new timing set in because I had already bought it, but I saved the old parts and I wouldn't hesitate to put them in a used engine that needed a timing set. Remember: If it ain't broke, don't fix it.

Everything you have mentioned is an option -- the question is, what are your priorities? Do you need to a fast & cheap swap to get it running, or do you want to put more time/effort/money into it to have an engine that will start out like new (the rebuild route)? Are you satisfied with the performance a stock 4.0L gives you, or do you want to boost the power as long as you're doing something?

Apples and oranges. He's talking spring rating, you're talking bed carrying load. The metric ton was rated for 2200 pounds -- which is what a metric ton is, hence the name.

It isn't the abrupt torque that'll do the damage. In the 231, the front and rear driveshafts are locked in 4WD. That means they both spin at the same speed. If the rear wheels are under power and spinning when you shift, the rear wheels are rotating faster than the front wheels. When you try to shift, all you're going to get is a loud, alarming grinding sound. It's exactly the same as trying to shift a manual tranny without the clutch, and not matching the engine speed to the road speed. It's entirely possible to do it, but you have to be abusive. It is synchro'd, it is possible to shift it in a way you shouldn't. I have seen it happen, granted not actually on pavement, but in similar situations where the rear is spinning and "I'll just engage the 4wd" happens. And if you tear the synchros and the teeth off the annulus, that was still torque that did it. I disagree. If you tear up the synchronizer trying to engage 4WD, it isn't torque that does the damage, it's phyical abrasion/interference. If you can't get the 4WD engaged, you can't even begin to apply torque.

Donald -- Go to your room.

Why spend money to do something you can do for free?

http://comancheclub.com/topic/52487-before-i-order-injectors-are-they-definitely-bad/

I agree with Cruiser. My '88 XJ has the CAD. When did I realize that it didn't work? Right -- when I was trying to get to work in a blizzard, and could understand why I couldn't make it up the first hill on the way to the office. That was long enough ago that I didn't know how easy it is to just lock the CAD in the engaged position, so I bought a replacement vacuum harness for it. Now that I know, if I get the '88 on the road this summer (as planned), I will lock it and forget it.

Doesn't matter. It's just an ON-OFF switch that closes a circuit if there's a brake failure.

It isn't the abrupt torque that'll do the damage. In the 231, the front and rear driveshafts are locked in 4WD. That means they both spin at the same speed. If the rear wheels are under power and spinning when you shift, the rear wheels are rotating faster than the front wheels. When you try to shift, all you're going to get is a loud, alarming grinding sound. It's exactly the same as trying to shift a manual tranny without the clutch, and not matching the engine speed to the road speed.

If it was neutral safety switch it wouldn't crank. I think you need a CPS.

It means shift at any speed up to 45 MPH. (Although I thought it was 50 MPH.) Just checked -- the 1989 owner's manual says shift into 4-Hi "at any legal speed." They may have changed it depending on the year.

I'm pretty certain you are referring to part number 20 in the parts manual illustration. It's called a "reinforcement," not a spacer, and it doesn't go between the flex plate and the flywheel, it goes outside of (behind) the flex plate.