So,

Recently, when temperatures dipped into the -20 wind-chills, my TJ
developed this strange "chirping" noise that sounded like it was
coming from the driveshaft between the transfer-case and the front
diff. When it first started happening, a quarter mile of driving, and
the chirping would stop. as time went on, it took more and more
distance for the chirping to stop...

I later found out that my front axle U Joints were shot, so, not
knowing quite how easy they are to replace, I had them replaced at my
neighbor's mechanic shop. . . he said that on his test drive after
replacing the U Joints, he didn't hear the chirping anymore.

Now, it chirps a tiny bit (maybe 10 seconds while driving between the
20-35 mph range) but then stops..

My question is, . . What damage can driving a jeep with bad front-axle
U-Joints cause? I'm thinking that the week or so that I drove it with
the chirping noise, I was damaging some other component in my
driveline.. True?

Still learning..

-Dave