hey guys/girls when i woke up today and started my integra, i heard a weird knocking coming from the engine bay that i've never heard before, i lifted up the bonnet and a knocking sound was coming from the gearbox. I got back into the car and pushed the clutch in, the knocking stopped when the clutch is engaged. Anyone know what this problem could be? i drove it today and it was fine but nothing wrong with changing the gears or anything, but when left in neutral the knocking is back :S i added a video to help

http://s231.photobucket.com/albums/e...t=IMG_2560.mp4