Metallic squeek from rear end upon acceleration- Grease U-joints?

Recently noticed a metallic squeaking noise coming from the rear of my 2006 Tacoma as I accelerate (isn't noticeable after about 15 mph) in both forward and reverse. Did a quick search and it seems like the most likely cause is that the U-joints need to be greased. Is there a procedural for that anywhere? Or, could it be another issue? Truck has about 125,000 miles.

 

I’m not sure what a metallic squeaking sounds like. I understand that that kind of stuff is difficult to describe. In any event you should grease the drive shaft U joints. Mine are done every oil change. The squeak could be from lots of things.

 

Sounds like it may be a stiff ujoint, I'd drop the driveshaft and check them all for binding. Also check the carrier bearing while your there.