I made three trips to get mine fixed.
1. After reading about low fluid levels in the differential on the TDR, I checked mine and it was low. Went to the dealer (Was not happy after waiting 4 hours for them to prepare the truck, and they didn't fill the rear diff). Anyway they diagnosed the rear axle seal leak and said that is why it was low. Since it was Sat. they could not fix it that day. Set appointment for Monday.
2. Took the truck in bright and early Monday and left it to be repaired. Got a call early afternoon, "Truck is ready". Picked up the truck, signed the papers, drove home and sat down to read the work order. It looked like it said that the seal was not available, so it was not installed. The English was bad enough that I was not sure that is what it said. I called the service writer and he apologized and said that the seal was not replaced because they did not have one. He said they had ordered one though.
3. After waiting a week I called to see if they had received the seal yet. They told me that I would have been called if they had,

but they would check anyway. They had the seal

and made an appointment to get it fixed. At least this time they actually fixed it. Have not had problems since.
It is a sixty miles one-way to the dealer.
Shannon