I seem to have inherited the same rattling, grinding noise my old 09 plate Focus developed soon after it's DMF was changed!!

The DMF on the Mondeo was changed last year before i bought the car, but as i never tracked down the source of the problem on the Focus i'm none the wiser why this is doing exactly the same thing (did the noise before i bought it). I'm getting a bit worried as it seems to be getting louder and was wondering if any of you guys had any clues?... i'm thinking a bearing in the gearbox as it only does it in gear! Worse under load (all gears) as you get a horrible rattly grindy noise which almost disappears when you let off the throttle, but as the revs go down it starts again but not constant, it's like somethings catching and it comes and goes quickly. The closer it gets to idle speed whilst in gear the worse it gets. Out of gear or with clutch in, there's no noise!

I've posted a clip onto Youtube from this morning, can hear it mostly around the 1:30 - 1:40ish mark 'catching' as the car is slowing down in gear. https://www.youtube.com/watch?v=VTU1vMOWkmg

Can't really make out much on the video, but from your description I'd say it's pretty much definitely the gearbox. Other than checking tou've got oil in it, there's not much you can do other than start saving for a new box!