Help Identifying Squeak From Rear Passenger Side Wheel Area

Howdy good folks of Tacoma World.
I've been having a heck of a time diagnosing a squeak that has popped up recently.
At first I thought it may be my leaf springs but the noise doesn't happen when stand on my bumper and move around so I kinda ruled that out.
The noise seems to only happen at low speeds in reverse. I was kinda thinking there could be a rock in the brake but I don't know how likely that is with drum brakes.
Any input would be greatly appreciated!
Here's two videos of the squeak in action:
https://photos.app.goo.gl/T4VdAhPw1WrjnLqb9

 

U-Joints. I just had to replace mine. That sounds exactly like mine did.
Here is my vid: https://www.youtube.com/watch?v=u-UKRbxpOhU

 

I had all 3 replaced. I cost me about $375 installed from a shop. No more noise now!!!

 

Sounds identical, you nailed it. Thanks!

 

That's not too bad as far as truck work goes, haha, based on some threads here it sounds fairly straightforward to do it yourself but I'll probably get a quote from a local Toyota place anyway.

 

No problem. I would try a local shop before I take it to a Toyota Dealer. When I posted my thread, people told me not to go to the dealership due to them saying that the dealership would want to replace the whole drive shaft.

 

I’d grease them really good until you get a chance to fix them.
Since you’ll be that far in, you might as well take a look at the carrier bearing.
If it looks like it’s in rough shape, I’d do it at the same time if you have the budget for it.