Identifying Squeaking

I've noticed a couple of different squeaking noises in my 5-speed v6 09 prerunner. I'm wondering if anyone has experienced any similar noises.

The first squeak occurs at all speeds forward. My first thought was the serpentine belt, but the squeak doesn't appear when the truck is idling, or when I rev the engine in neutral. It seems to occur when going over bumps. My next best guess is U-joints, but the squeaking seems coming from the engine bay, not the drive train.

When in reverse, there is what I believe to be an entirely different noise that I strongly suspect is the U-joints. It seems to be a cyclical noise, as I accelerate in reverse the noise gets faster, and vice versa. Wondering if anyone can confirm or deny my suspicions.

https://youtu.be/XcobSOy3Dyg

https://youtu.be/pw5_J9P_8-k

 

I don't hear anything in the first video.

The second one, I'd suspect U-joints as well.

 

The noise in the first video is very subtle. You can hear it at the 3-second mark and again at the 11-second mark. If it is the U-joints, is the only option replacing them? As far as I can tell none of the 3 U-joints on my truck have zerks, so just packing them with grease seems off the table. While the squeaking is annoying, they don't seem to have any play. Then again, the truck has 130,000 miles on it and as far as I know, they've never been replaced.

 

Replacing them is the only option.

The noise is rotational.
You might put the truck on jack stands and CAREFULLY look/listen for the noise while it's in gear.

 

As an update, the noise in the second video turned out to be a worn-out rear U-joint, replaced it last weekend, and problem solved.