Does it go away when the clutch is disengaged? If you do alot of driving with alot of weight in the truck, firewood, scrap metal, or whatever, to not use fifth gear! I found this out on my truck, was doing alot of wood cutting for the winter and one day had this noise that sounded like a throwout bearing going bad. Well, it wasn't the throwout bearing, but the middle bearing that takes all the load when in fifth gear inside the tranny!
But it could be anything, so it sound like ya need to investigate a little further! And get back to us!
i cant use my 5th gear when my truck has a load, if i try to use it, i have no power and barely move
