urban legend, if you have a bearing loose in there, someone dropped it in, or some gravel - most likely you have an old sender float, or part of it, or a baffle broken loose
"When we tug a single thing in nature, we find it attached to the rest of the world" ~ John Muir "When we tug a single thing on an old truck, we find it falls off" ~ me Some TF series details & TF heater pics