Hi All, 06 Silverado 1500 5.3 When I accelerate from a stop, tranny shifts fine. If I give it a little extra gas, or hit the gas hard, I'm getting a clunk and it sounds like something under the passenger cab of the vehicle. The truck shifts smooth, does not slip and runs great. Only annoying thing is this clunk that sounds like my truck body is going to fly off the frame!!!!! I do not feel anything in the steering column. Any thoughts?