I have a group of unit bearings sitting at my home in Spokane... the unit bearings on the 05 that I own are the same no matter if its a single rear wheel or dual rear wheel...
If when you do brakes, you can pull the abs sensor you can lube these bearings. . I suggest if you try and lube these, that you use a full synthetic grease. The ones I purchased for stock I had lubricated with a full synthetic grease for what we hope is better life... I think between the Ford's and the Dodges I've sold maybe a couple hundred of these...
We have pressed them apart, cleaned them, lubricated them and reinstalled them in our own trucks... I've never done it for a customer, just sold him new ones... I do know from having them apart and back together, that lubrication through the ABS hole works. .
The only installation problems I've personally encountered were ones that were rusted into place... of course I've coated them with a never seize upon installation, and I've not been back to one of those trucks...
I hope this helps... .
BTW I agree with Rob above... . the can't be repaired but can be serviced and re-installed if the bearings and races are in good condition. But it takes a fixture and press... . but when you own several of these trucks and you have them apart for other reasons its a suitable answer to replacement if you have the time.