whirring/grinding noise coming from rear end

[Kwik03DSG]

Hi guys, like the description says, im having some noise coming from the rear end of my car. starts up at about 35mph or so, with a loud whirring and vibration on deceleration. I took it to a local shop and they checked the fluids; they noticed alot of metal shavings on the filler plug. One person suggested the pinion bearing might be out. does this sound right to y'all? and if so, Is this a part one that fails commonly?