I have a very faint howling noise that my truck is making. Only makes the sound between 45 and maybe 60ish mph. Only does it under acceleration. When I let off the gas the noise goes away. Its not very load at all. If your not listening to it you might not hear it. Thank you..

 

Having the same issue. I'm in CT and the weather's been hanging around 25-35 degrees the past few weeks. That's when I started noticing it. Any info would be great.

 

it might be the intake sucking in the cold air. My k&n gets a little loud during the cold winter months.

 

Is this noise probably coming from the rear diff? I have the exact same thing and am positive it's the rear end. I'm gonna check/change the fluid and inspect things while I'm in there.

 

I kind of dont think its that. Cause that actually started happening and im sure it was the intake cause of how cold it was around here. But that was 10 times louder and doesn't happend very often. This one is really quiet.

 

It very well could be. Its kind of one of the noises also that you can't totally pin point the directions its coming from. And i dont recall hearing a differential that did at a certain mph. Only problems on previous vehicles that ive incountered that would be a constant howl of some shape or form at generally any mph.

 

I had the same sound, turned out to be the rearend - ring and pinion.

 

Alternator. Do a search on here. Nothing is wrong with it just happens with the trucks.