i have a noise coming from my truck. when im going dwn the highway if i give it gas u can hear a whinning noise and when i back off the gas it changes tone but its still there. when i give it just enough gas to match the speed of the tires with the RPM it goes away. my carrier bearing is old but it does not show signs of failure and has vary little lateral movement. however with the truck parked in neutral and the Ebrake on i can spin the drive shaft a good amount. not quite a quarter of a turn but u can def move it. also there seems to be a jerking motion when im accelerating or deaccelerating like there is a large amount of play beywwen the tranny and the tires.. its not the transmission. my best guess is its the rear or 3rd member starting to go. has anyone else had this problem.