Clunking noise under decceleration

[SB0409]

i was driving today for college and about a few miles out, i left off the gas due to a speed change and i hear this loud very rapid clunking noise that didnt go away with extra braking. I was going about 55mph and the noise did not disappear till i got to about 5 mph. It seems to happen only under decceleration and anything above 5mph or so, you can hear it audibly from underneath teh truck but i cant tell where the vibrations are coming from. Any help would be great, thanks.

 

[pjtoledo]

give the driveshafts a good look. does the rear shaft have a big balance collar that broke loose?
lift 1 wheel at a time and spin slowly feeling for any pulsating.

2wd or 4wd?

 

[rusty ol ranger]

Could be a carrier bearing flopping around too if your truck has a 2 piece driveshaft