We had a total hub failure on one of our '03 4 wd sd's this week, right front bearing went away locking up brakes on a Patrol trucks up near Gurlock NV.(Kind of like 100 miles from nowhere.) We were working on the LA DC line during an outage. We found one in Reno, but our Mec's boss figured it was better to send a Truck driver from Independence CA, for 15 hours of Double Time to haul it 400 miles to LA for the warranty work. Heck the fuel they spent would have covered the parts and labor.
But at least I saw first hand a total failure. My own personal '99 has had 2 sets go bad in 95k with only leaks of the seals.When is Ford going to take some responsibility for these hubs?????

 

This is an issue that's been kicked around here very often.

There is a bearing upgrade for the '99's, at least that's what I recall.

 

Go to Dynatrac's website and check out the REAL bearing kits for the SD. A REAL fixed spindle, REAL tapered roller bearings, and REAL reliability. No, I don't have any affiliation with them, but that's the route I'm going when my hubs take a dump.

Cody