Eagle

80/90 gear oil is what's called for. Synthetic gear oil will make it run a lot quieter and shift a lot better when cold.

Most clerks at Autozone don't know anything. He probably figured they're all the same. I have three Autozone stores in more or less an equidistant radius around me. Out of the three stores, there's one guy who works at one of the stores during the shift when I usually can't get there who knows anything. The rest of them are total ciphers.

It was an option. The SporTruck definitely didn't have them, and my '87 Pioneer doesn't have them.

Anything can be taken apart. If you do, then it won't have brake fluid in it, you have to re-bleed the system, and the light will come on again so you'll be right back where you are now. It might help if you remove the plastic switch part on the top of the metering block -- that's the part the wires go to. Then stomp on the brakes and see if the slider will center itself.

A '91 with a 4-speed is not "late model." This thread started out asking about 1996 axles.

Not quite. 4 cylinder/4 speed stick (AX-4) have 3.55. Supposedly (have not been able to confirm personally yet) early 4 cylinder/auto had 4.56. I'm sorry. I meant to say all "Chrysler era" 4-cylinders. Yes, the early AMC XJs and MJs had some ratio variations, especially behind the 4-cylinders. Chrysler did away with all that. That's what was intended by my reference to "late model XJs."

It won't help. The purpose of the thermostat is to keep the temperature UP, not down. If your cooling system can't cool down to 195, it certainly can't cool down to 180. Quadratec has new pressure bottles for about $25. be sure to get the one with a new cap ... I don't think anyone has ever been able to get a seal using a new bottle with an old cap, or a new cap with an old bottle. And do NOT "top off" the bottle. Liquid does not compress, so when it heats up it has to blow the lid off. The bottle should be filled to the halfway mark (there's a post inside) when cold. Do not fill it beyond that.

You can use the center hole if you replace the center pin in the spring packs with a standard grade 8 hex-head bolt.

no, that's regular amc20's (NOT comanche amc20's...those are 1 piece) Pretty sure I remember posts about 84-85 D35 shafts being 2 piece. You may remember such a post but, if there was one, I believe it was in error. Simple test -- if it's a 2-piece (with the hub splined onto the shaft like the old CJ axles), there will be a nut holding the flange on. No nut = 1-piece axle.

Pressure cap? Expansion tank? What year vehicle is this? If it's a 1990 or older 4.0L, that tank is not an "expansion" tank, it's an integral part of the cooling system. The cap IS a pressure cap, and if it isn't holding pressure, that's why your coolant boils. How high do you fill it? It is supposed to be filled halfway when the system is cold. If you overfill it, there is NO expansion tank, so the expansion of the coolant is what's popping the cap.

If shopping for new shafts for a Dana 35 axle, don't forget that from '84 (XJ only) through '89 they did not use a c-clip retainer, they were retained by a flange at the outer end. From 1990 through 2001 they used a c-clip retainer. They are not interchangeable.

An 'L' stamped on a stud indicates a left-hand thread ... which was never used on the XJ or MJ.

No, the ratio will be stamped into the edge of the ring gear. It is unusual not to find a ratio tag on a front axle. I've looked at old XJs and MJs that were sunk right up to the pumpkin in muddy fields behind old barns and still found the tag intact.

A ZJ rear will be another D35, or a "Dana 44" with the crappy aluminum case -- the only axle in the universe that's WORSE than a Dana 35. And there are no late model XJs with 3.73s. From the factory, all 5-speed 4.0Ls had 3.07, all 4.0L automatics had 3.55s, and all 4-cylinders had 4.10s.

alright good but is there anyway that i can recalibrate or something like that? Yes, it can be calibrated ... but you don't know if it's wrong. If it ain't broke, don't fix it.

Put the rear axle up on jack stands, start the engine, and let it idle in first gear. See if the wheel wobbles. It could be just a bent rim. If the wheel wobbles, take off the wheel and repeat with only the brake drum in place -- see if the brake drum wobbles. If the drum wobbles, remove the drum and check just the flange. You look for a new axle only if the flange wobbles.

That first tick above the zero IS 500 RPM. Your needle is pointing slightly above the 500 mark. Idle spec IIRC is 650, so you're close.

Correct. The ZJ was offered with a 5-speed only in 1993 and VERY few were sold, so for all practical purposes there are no 3.07 ZJ axles. A ZJ axle is probably 3.55 or 3.73. As noted, it will be a low pinion, and it will use the horrible composite rotors that like to warp every other week. If the ratio matched it would be better than nothing if it's free, but regearing it will cost $$$ so it's probably better to keep looking for an XJ or MJ Dana 30 with the ratio you need. Unless, of course, your plans include changing the rear axle ratio.

You are reading the tachometer incorrectly. The photo shows it reading approximately 550 RPM. The first mark above the bottom is 500 RPM.

I'm confused. What's this about splices and extra wires? The cluster swap is (or should be ) 100 percent plug-and-play at the dashboard. Take the old one out, put the new one in. The ONLY changes necessary are to replace the temperature sender in the head and the oil pressure sender next to the oil filter with the senders for use with gauges. Did you cut and splice wires under the dashboard?

The light on an '89 doesn't mean much. It is activated by a mechanical timer and it's nothing but a reminder to replace the oxygen sensor. Most of us have unplugged the light. The O2 sensor should be replaced about every 75,000 miles.

The seal is on the inner end of the tube. To replace it you have to remove the differential. Big job. If the axle is going to get replaced, just keep an eye on your fluid level.

:doh: First thing to check. ALWAYS. My bad ...

I REALLY disagree with this. Just "dropping in" a 258 (4.2L) crank and rods creates all kinds of problems. It is not a simple plug-n-play swap. The two engines had slight differences in deck height, which translates to a high compression issue with the "budget" stroker. If you are not prepared to deal with that, don't even start.

Oil pressure is lower at low engine RPMs. Your problem could be the sender, could be the poil pump, but most likely is the rod bearings being excessively worn. What year, what engine, and how many miles?