There are some tests that should be run before condemning this unit. Does the vibration go away with the vehicle rolling with the ignition off? Does the vibration appear without the vehicle stopped, but the engine operating at the same rpm? Are there guarantees that the tech is not guessing? If the crank is really the issue, a new engine will likely guarantee a repair. Considering the possibilities presenting with crankshaft issues, including pistons, rods, bearings,etc, the engine is likely the way to go. Ray