Grinding noise in front end, possibly 4x4 hubs.
I have had this same problem since my truck (05 f150 4x4) had about 22k miles on it. At random intervals of sometimes every 5 minutes and sometimes 5 months my truck will make a grinding type noise in the front end. It sounds like bb's rolling around in a coffee can (except very loud). I have taken it to the dealer several times and they could never pin point the noise because it was happening so randomly. I now have 56k miles on the truck and it happens more frequently. The dealer just had my truck for 3 weeks trying to figure it out and they can't. They did hear the noise but couldn't figure out where it was coming from. Anyone else have this problem or any idea what it could be?