todays "name that noise"

[StonecoreTx]

I've noticed a noise coming from my rear end and havn't had the time to attack it yet but open to any ideas.
Sounds like a single clunk everytime the wheel makes a full rotation but goes away under load. sound stops when accelerating.
It happens only when coasting to a stop, low speed turns, slow reverse.
my diff is fine and full of a bluish performance gear oil and boots are good.
someone said it might be a bad caliper or wheel bearing but maybe not becuase it goes away under load...
maybe a dry driveshaft?