HELP! noise from transmission?

[palooza]

I have this loud *** grinding sound, almost like..."wong..wong...wong....wong" or "ing...ing..ing...ing" when i let off the gas with no clutch in . It happends around 3k rpm. happens mostly in all gears i cant tell if it happens it first or not cuz people on the road would get all pissed that im going too slow. And im not too sure if it hapens in 5th cuz I'd be over speeding by the time i hit 3k rpm. its get slower and the car slows down. but yeah...its kinda like a grinding noise..almost like a bike when you pedal backwards..but not exactly...I changed the pilot bearing but nothing...still the same...could it be the TO bearing?..i dont know cuz.its new. I just put in a act 6 puck. and i used the TO bearing tht came wiht it. so im not too sure whats the problem. i also put in a fidanza flywheel. but i dont think it could be the problem.I also tried thicker gear oil. nope same o. we even tried using the older TO bearing from the stock clutch (which at the time when i drove it to the shop, was just fine). so anyone PLEASE HELP!!!! I got some autocross action on march 6th. i need to make it!! theres prizes!!

[palooza]

anybody???

[xyoufailmex]

So if you clutch in, it stops making the noise? It could be your differential... or it could be you need to tight your lugs.