shell-bell73

so i take my f 150 lariet 4x4 crewcab to the shop because it feels like im on gravel when taking off not 100% of the time just like 80% of the time. then i was running it on the highway for a good while. when i got to where i was going it make this grinding sound when turning.(more like a rubbing moaning sound) but doesnt do it ever until i run long distance on higways.. ughh! So the guy says its not rear end problems going to check the transmission. that came back clear. now going to check the transfercase and if he finds that all clear he dosnt know what to tell me. frustrated! anyone have any advice on this?

RLXXI

Sounds like you need to put some friction modifier in the differential. Google Ford friction modifier