My 2007 GX470 runs like a Switch watch as always, but i have lately noticed a noise when in motion. It sounds like tire or road noise. It is not from the engine as it corresponds to the speed of the vehicle. Maybe it is road noise, but the rub is that i never noticed such a noise previously. The tires are in good condition. Transmission fluid appears to be full, even though it is so colorless that one can hardly observe it. I have never checked my differential fluid - that is tough to remove - but neither have i observed any leakage. I would greatly appreciate thoughts on the issue. Thanks.

Just occurred to me that i should evaluate the brakes, but i doubt that is the source.

 

What's the mileage?
Check wheel bearings. Might be the issue. My bearings went out at around 165k.

 

Front brake calipers are notorious for seizing on these trucks. If the noise can be heard at low speeds, have someone walk beside the truck and pinpoint which corner it's coming from, then dig in and see what you can find. If the pads are wearing unevenly, there's a good chance you have a seized caliper.