I have an LT4 with a six speed transmission. There is only 10,000 miles on the car. In fifth and sixth gear, starting at about 65 mph, the transmission sings, and it is not a pretty song. The whining only happens under load. If you let up on the throttle, it goes away. I suspect that it is a bearing on the 5th/6th gear shaft. Has anyone had a similar problem? Anybody have any luck with GM fixing it out of warranty? Thanks.