Screeching Sound from right wheel area

I am posting this in the OEM section, because I think it is an OEM problem, not a modified... despite being modified.

Background:
Just swapped to a new axle for the front & rear. It's a D30, just like my original one, except this one has a Detroit Tru-Track, and 4.10's in it. Upon the switch, I basically swapped everything that I've always had on my old one besides the actual differential. I used my old axle shafts, rotors, calipers, etc. I put in new U-Joints in the front, not spicer as they didn't have any... "tough guard" i think was the brand... When I did the switch I did have a problem with one of the bolts on the caliper, So i used the bolt that came with it, which was bigger, but kept the sleeve but had a larger screw in it, so it'd fit tight.

The Problem:
I have a screeching sound from what I can tell coming from the front passenger tire area. It seems to happen both with the brakes pressed and not. I drove 70 miles day, and for 99% of the trip, no sound was made, just ran great. It does seem to be a lower speed thing though. From 0-25mph, but does not always happen at those speeds.

Things I've done so far:
I've torqued all the bolts again. Removed the caliper, double checked it. Everything has been within spec. The differential oil is at the proper height, etc.

Solution?:
I think it may be the u-joint. When I put it in, it wasn't free nearly moving as the one on the driver side. I could move the drive side one by hand easily (without using the leverage of the axle shaft), while the passenger side one (problem one) I couldn't do it by hand at all.

So any guidance on my thought is correct then let me know.

Most times my bad front axle U-joints don't make any noise, unless I'm turning. I gets worse in 4X and turning. If it's screeching you can likely pull a cap and see rust instead of grease in the needle bearings. The rubber seal between the cap and and the cap base often shows a ring of rust dust. A sure tip off that the needle bearings are dry.
I've had some issues with the axle stub nut before. The hub bearings didn't want to seat just right and got stiff, some side pressure came from somewhere. I'd over torque the nut, back it off and torque it to 150. Run it for awhile and then torque to 175 (depending on the XJ year). I can imagine side pressure on the hub bearings could cause a squeal.
Maybe put the front on jack stands, if the U-joint is bad you are going to need to replace it anyway. Pull the calipers and the discs, turn the steering wheel to right or left lock and see if the bearing gets stiffer (needs more effort to turn the shaft), then try it again with the wheel straight ahead. You'll probably get better results if you disconnect the front driveshaft. You can often feel bad bearings while turning the axles by hand, they rumble a little, hitch and stick a little.
If you were a good Jeeper and greased the outside of the hub, before you installed it, things should come back apart fairly easily. I'm sure you know this, but if you just jack up the side your working on (left or right) really high, you won't have to drain the oil or worry about it running out the axle tubes.

Thanks 8Mud for the advice. Just as I was reading your post, I got to thinking, and realized the cotter pin on the axle shaft or hub or whatever, was not bent correctly, as I tried to remove it... (braing fart moving it, and not bending it back). So I bent that back, thinking it might have been scrapping the rim causing the noise. So put the rim back on same noise, and simply turned the wheel. Instantly I heard the screeching sound.

At this point I was ready to take the axle shaft out just to play with the u-joint so I could eliminate that from my mind as being broken. As I am doing that I noticed the rotor 'guard' was shiny... That's not supposed to be shiny. So the rotor has been grinding against the guard. I bent the guard back a bit to make sure the rotor cleared it, and took it for a test drive and no noise. Although it was a very short test drive, and I've gone further than that before without it making noise, I am hoping that was the problem.