Recently noticed that if I accelerate hard from a stop or stop hard there is a clunk in my drivetrain. Done some reading and of course I was leaning towards a bad u joint but also did some reading and learned that the slip yolk sometimes has a tendency to stick. Yesterday I got in and notice a squeak coming from the rear of the truck. It starts at low speeds but once I get up to cruising speed its gone. I was leaning towards my breaks but it doesn't seem to change if i hit my breaks

 

The squeaking is probably the u-joints. The clunk is probably t5he slip yoke.

 

The squeak sounds just like what mine did, I had a rear ujoint that was full of rust and powder... The clunk could be the ujoint to, hard acceleration could force it to move faster, causing more of a bind. I would do the ujoint first, cheap and fairly easy.