I was going to work in it one morning and it popped real loud seemed to come from R/side latter on it did it again.Then that afternoon it locked the whls put it in 4whl but didn't lock hubs and it seemed to drive hm ok.It has a Dana in it but not sure of #.Where should I start looking.Maybe a brake pad has came loose are what?
![Image](http://i833.photobucket.com/albums/zz255/ezmerf/fordtruck-72.jpg)