Please help with noise from bell housing

I have an 07 Volvo 780 with the eaton fuller 10 spd autoshift, 3 pedal with clutch, volvo d12 engine. 668k miles. I have a noise/rattle coming from the bell housing. When sitting at idle it is there almost constantly but not so loud, not noticeable when inside the truck. When rolling and my foot is on the gas it disappears, it is most noticeable when I am coasting and take my foot off the gas pedal, it gets even worse if I am coasting and on a rougher surface/bouncing. Still in those situations it is not constant, it comes and goes for seconds at a time usually depending on where I hold the accelerator pedal, and of course I can feel it in the pedal. Any ideas? $?

 

Clutch release/throw out bearing...those are the same thing right? I'm at the Volvo dealer in Austin right now. Interesting note, the noise/vibration also got worse with my rear suspension getting too high. (My leveling valve went out yesterday too) The technician said he didn't feel or hear anything during the test drive after replacing the valve. I can still hear it when its sitting still idling. He doesn't seem to want to do any #### thing here...but I finally got him under there and he noticed it, also suggested throw out bearing. Is that possible since it is still making the noise when not moving, just sitting there in neutral? I just bought this thing in October, not sure when that bearing was last greased, unless speedco has been doing it during my pm's. It