redneck tumble

Securing a barrel or container of liquid or powder to the rim of a large wheel, such as on a tractor, and slowly driving around as an inexpensive means of shaking and mixing the contents of the container.

(referring to an old fuel tank) "There's quite a bit of gunk in there, looks like it's pretty thick on the bottom, so I think we're gonna have to give this thing the ol' redneck tumble."