i have a 2005 f150 4x4, just the other day i was driving and i heard this grinding sorta noise only for a couple seconds and it went away. a while later i firgured it out, it was the transfercase, seems like its trying to shift int 4x on its own... it already wont shift into 4x with it moving... i already screwed that up some how, it just grinds. but why would it try to shift on its own without touching the switch? i ended up taking out the two "PCM 4x4 power" fuses, hasnt done it since but obvously not the way to fix it... help?