In my 91 f-50 the hub on the drivers side makes a grinding sound. My dad and me are going to throw in manual hubs. My dad went and threw my truck into 4x4 becuase are driveway is on a hill so it's covered in snow and ice. The front wheels weren't even grabbing.

 

Good Idea I did the same thing on my old 94 f-150 and they worked great and you don't have the disadvantage of them unlocking when you back up like the auto's due I think you will be happy with them .. I went with Warn manual hubs they are the best you will find for a reasonable price good luck