AZJeff

If you take the Jeep out on the highway (where you can keep a sustained speed of 40+ MPH, and the engine stays at an acceptable temp, then you can dismiss any issues related to airflow over the radiator, as at that speed, any fans are not needed. That would be a quick test. Just revving the engine up to higher speed for a few minutes won't demonstrate cooling system function correctly, as it takes time for the engine to generate the added heat of higher RPM, and it's takes time for the coolant to absorb that heat and then attempt to transfer it to the air via the radiator. You need a sustained higher engine speed to demonstrate proper water flow conditions. The fact that the engine heats up and cannot dump the heat at higher STEADY RPM makes me inclined to agree with most of the other posters---you are not getting proper water circulation.

You say "temps drop at high RPM's" What exactly does that mean? Is that high RPM's that relate to high(er) road speeds, or just higher engine speed? I ask because the engine will generate more heat at higher revs.

D35 axles have their bearing rollers ride directly on the axle shaft, and the axle functions as the "inner race" for the bearing. The outer race for the bearing is a LIGHT press fit into the bore of the axle housing. A block of wood and a few taps are all that it should take. Anything more than that, and something is wrong. Either the bearing is the wrong size, or something is inhibiting the bearing from seating in the bore of the axle tube. There is a change in bore diameter in the axle tube that acts as a stop to prevent the bearing from being driven too deep. The seal for the axle shaft is a slightly tighter fit into the axle tube. It is coated with a colored sealant on it's outer surface, and thus needs to be driven into the bore of the axle tube with a block of wood and a dead blow mallet until it is FLUSH with the end of the tube. If the seal won't seat flush with the end of the tube, you have not got the bearing seated into the axle tube sufficiently. By the way, check the surface on the axle shaft where the bearing rollers ride. If the shaft is scored, heat damaged, or exhibits spalling, the shaft must be replaced, or the axle will trash the new bearing in short order.

I am new to this forum, but I have been working on cars for 40+ years, and XJ's for 15+ years, so I know the needs of the XJ/MJ community. The old tubular 3-legged jackstands are not the most durable, and can fail pretty dramatically if they welds on the small cross-straps at the bottom give way. There are LOTS of more modern four legged jackstands out there that will do the trick. I recommend "over-buying" to some degree. For example, an MJ is well under 2 tons, but a 3 ton jackstand is what I would choose, since when used in pairs, they will LOTS of design margin over the actual vehicle weight.

That's what I thought. Now all I gotta do is find a swaybar....

I want to re-install a front sway bar on my 1989 MJ, and I always assumed that all sway bars for the MJ/XJ family were the same, and only varied in diameter from year to year. But...I several places I have searched, they talk about the sway bars for later XJ's only fitting vehicles from 1991 or thereafter. Is there any limitations to putting a sway bar from a later XJ onto my MJ? (Yeah, I know I need the right size bushings and appropriate end link kits.)