98 Silver 4X4 humming when decelerating

There is a very noticable humming noise coming from my truck when I take my foot off of the gas after going 65mph and occasionally even when slowing down around 30mph but more often after being on the interstate. Any ideas or help would be greatly appreciated.

Sorry, I just realized that I posted this in the wrong section. I still would appreciate any help. Thanks. :)

There is a very noticable humming noise coming from my truck when I take my foot off of the gas after going 65mph and occasionally even when slowing down around 30mph but more often after being on the interstate. Any ideas or help would be greatly appreciated.
I had the same problem with my 97 GMC 4X4 turned out to be the pinion gear in the rear end was worn out and had to be replaced. Runs great now problem solved.