Had intermittent shuddering and sounds as if I had a flat tire. It usually happened when in stop and go traffic at 20MPH. These sounds would go away. The Ford Dealer was a joke and a waste of time. Fixed by local shop. Drivetrain replaced.
Rear drive shaft assembly replaced.
Low growling sound, apparently was a bearing in the driveshaft, replaced under warranty.
Whine developed over last few months. Dealer initially uspected axle bearing. Replaced and found not to be cause. Dealer then found TSB and replaced centre axle (AWD) and this cured it.
Blew transmission. Dealer advised it was first one in Canada. Took 1 week to diagnose - Ford authorized R&R of complete transmission. 2 weeks to ship transmission (nearest one in Memphis) and a few days to R&R. Lincoln warranty covered rental car.
replaced rear axle shaft assembly
replaced Power Transfer Unit (transfer case)
Buzz sound from under car, noticeable at low speed, rear driveshaft for AWD replaced.