Driveshaft related metallic spinning noise- agree?

[2003x5guy]

I put a post on here a few weeks ago about a mysterious noise but no one had any good suggestions. Rightfully so, seeing as how vague I was based on the lack of really any info I had.

Well I believe I have narrowed it down.

Noise is characterized as metallic, spinning,"rubbing scraping sound" But scraping hollow, not low pitched. unrelated to wheel speed. related to RPM (It occurs like a bent bike tire rubbing against the frame in one spot, but more metallic)

While driving and hearing the noise I shift to neutral, sound immediately goes away. Rev engine in park or neutral, no noise.

So not engine, not wheels must be drive line.

After heavily searching on the internet. I believe I have narrowed it down to 3 plausible culprits.

1. Center Mount Bearing or (Drive Shaft Bearing, CSB)

2. Transfer case.

3. Drive shaft CV joint (I don't believe its this, does not match standard sound)

I just stuck my head under the car and looked at the CMB. Rubber seems flexible and resists my push and pull on the shaft.

I twist the rear shaft back and forth and listen. I only hear the strong clink, clink of the teeth connecting. Seems fine.

I scoot to the front shaft (before the Transfer Case). I twist it. Nothing weird.

I grab the front shaft,push and pull up and down and I HEAR SOMETHING. Very faint but sounds metallic. Almost like picking up a metal ball bearing and dropping it on metal a few millimeters up.

I believe the bearing inside the transfer case may be bad.

Would account for the "bad spot" in the spinning scraping sound

Questions:

1. Sound plausible? Agree?
2. Does anyone know if its possible or worth taking it apart to change one bearing inside the transfer case? Seems less expensive that way.
3. Other ideas?

Thanks