Noticed a whining/whistling noise today after merging onto the highway and increasing speed above 40mph. Kind of strange though, because after about a minute or two the noise seemed to diminish. Just had my 60k mile service, it's an 06 Rubi 6 speed, and I am actually bringing the truck in next week for engine seal leak so I'd like to have something to tell the mechanic when I drop the truck off. I am thinking it may be bearings but why does the noise seem to go away after the truck has been at a constant 60mph for about a minute or two? Is this an early sign that things may get progressively worse?
I know I did a bad job at describing the issue so please excuse my lack of knowledge on the subject. Any help would be great.