Gumbys69

I'm a noob to the forum but have had many GM trucks from new Colorado's, 1500's and i just grabbed a 2015 GMC 2500HD Denali 6.0L gas to pull a fifth wheel twice a year. This truck is super clean and has 141000kms (87000 miles) on it but from around 30km/h to 55 km/h it has a noise that sounds like a bad wheel bearing or tire noise. It is definately a rotational noise at that speed, you can put it in neutral the noise does not change, either in 4wd or 2wd it is the same. When i first bought it the tires were a cheap chinese tire so i swapped them out for new ones and the noise is still there which would eliminate tires. Usually on a wheel bearing when you swerve side to side you can change the sound of it as the bearing becomes slightly unload but this does not change when i do that. I ran it in four wheel drive on the hoist and there was no noise and zero freeplay or noise when spinning the wheel by hand. I checked and replaced front/rear diff oils and transfer case oil (all were fairly clean with no contaminents). I have searched and read numerous pages on certain noises but nothing seems to have a solid answer, so i guess my question is are these trucks common for this? Has anyone heard or seen anything like this?