Hinterle

2005 Z51 with 6 speed. 25k miles. When accelerating harder than normal, but not "standing on it" I feel a slight high frequency vibration between 3500-4500 rpm in first and second gear coming from the rear. Switching traction control off does not affect it. Did change rear dif oil but no change. Does appear to have some affect when the suspension is moving up and down. Thoughts???

extrapilot

Things that spin fast enough causing a high frequency vibration could be related to the torque tube components, the couplers and bearings come to mind. This is only a guess though.
Might be a good idea to call on a trans specialist.