Whining noise

I have a 00 Silverado Z71, 4.8. 6 inch lift running 305/70/16 tires. Truck has 319,000 miles, original motor with I asked 4l60e transmission.
I recently noticed a whining noise that sounds like it is coming from the left front area.it seems to start around 20 mph. It I'm really noticeable when the windows are up. I've had my head out the window at 50 mph and can't hear a thing. But when I roll the window up it is very pronounced. Anyone have any ideas?

Hub bearing, front axle (carrier and pinion bearings), brake rotor, and numerous other guesses.

I have a 00 Silverado Z71, 4.8. 6 inch lift running 305/70/16 tires. Truck has 319,000 miles, original motor with I asked 4l60e transmission.
I recently noticed a whining noise that sounds like it is coming from the left front area.it seems to start around 20 mph. It I'm really noticeable when the windows are up. I've had my head out the window at 50 mph and can't hear a thing. But when I roll the window up it is very pronounced. Anyone have any ideas?

most likely a bearing.... if the drive train has no leaks then my guess is the hub bearing.....

when I do my brakes front.. I remove the rotors and the speed sensor then I give the hubs a good amount of grease pumped into the sensor hole..

if the grease looks bad then that sure may be it.. if after you grease it and it is fixed or reduces now you know ..

I did this before many years ago and I got 4 months out of it till I had the parts/times to do it...