Strange Noise when on very low revs

Hi pals..I'm getting a strange ' Brrrrrrrrrr ' noise up from the gear lever whenver I'm doing very low revs.. It seems that it has to the something with the gearing system since sometimes when I get a good grasp of the gear lever it stops..it's very annoying especially with the windows closed.. What can it be?

it's called a rattle. It might be Paulus's coz he keeps throwin his outta his pram.

????