vibration at 3000 RPM and up

[NISSAN240SX12]

Ok my 240 has a KA24de w/auto transmission..... I know don't tell me i need to swap it out to manual... lol well anyways I have a vibration that occurs at about 3000 RPM and up. I doesn't matter if its in drive or park. I have checked so far the motor mounts and transmission mounts. while running to engine doesn't shake hardly at all. i had my friend rev the engine to 3000 rpm and poked around and it seems that the vibration is mostly at the trans. anyone out there experience anything close to this. just trying to find some input on it. thank you all for your help!