a few months ago i noticed when i really punch it in my 89 f350 it will make a grinding noise, but only if you punch it off a stop light or something, the carrier barring on the drive shaft is wore out and needs to be replaced and for a while i thought it was that, but a few days ago i put in in 4x4 low going up a hill and the grinding started up but i leaned out the window and noticed it was coming from the motor or somewhere up front any ideas?
the tranny shifts fine and has no problem going in or out of 4x4, it has a fairly new transfer case as well as tranny in it.
if the info i gave doesn't help i will go out again with my video camera and record the noise and post it, heres a link to the video i made of it.
7.3 grinding noise? - YouTube