I hear this knock when the car idles and when its driving some times, when i hit the clutch the knocking stops. I think it may be the shaft bearing inside the tranny? the sound it coming from the clutch area but its a new XTD stage 2 clutch and flywheel. And i put reg 10w30 in just to idle it and move around a bit. If it is the bearing what is the cost to replace shaft/bearing or dose a tranny shop have to do it.