Noise in relation to speed when decelerating

I tried searching, but not sure what kind of terminology to use, so I found nothing on the matter.

So this morning I noticed a noise when I was coming to a stop. Not sure how to describe the noise, but it's a wavering noise that slows down with my speed. I thought it was my brakes, and thought it might've been because they haven't warmed up yet, so didn't think too deeply into it. I'm on lunch now, and as I was driving home, I realized the noise was from me decelerating, regardless of brakes.

If I had to assume, it's a u-joint or maybe even the mid-shaft bearing possibly.

I did lube the u-joints when I purchased the truck, as advised by the forum.

Anyone have any thoughts on this matter?

 

Mine does this too, seems to be more prevalent in the morning/wet or when cold. Cant figure out what it is. Let me know what you find out, meant to ask the dealer last time, but figured I'd get the run around again.

 

Got an appointment on Monday. Will post results

 

Thanks man.