My 940 turbo (140K miles) has a sharp vibration that worsens with load - worse with a car full of people or full trunk and at fuller throttle. The car did it a little even when new when the trunk was heavily loaded and it has gotten gradually more noticable over the years. Yesterday it got sharply worse, is obvious at all throttles and can be felt initially just as the engine spins up on starting. The driveline appears fine - CV joints and driveshaft support are not obviously deranged in any way. Some folks locally told me it was a cracked flywheel, probably not the torque converter. Thoughts? What is a reasonable repair estimate? Any tricks to doing this myself (I have experience with engine overhauls, etc., years ago.)