At a glance
What can fail
The seal on the drive axle differential can leak, reducing lubrication. This makes the differential noisier and can damage internal parts. It may jam when shifting to reverse, cause drag like the parking brake is on, or lock the drive wheels while driving.
What the fix does
The dealer will replace the drive axle differential seal or seals.
Summarized — see the official notice for exact wording, dates, and contacts.