Rear axle bearings?

In the last week I've got a hum/buzz noise coming from the rear, that's most noticeable above 60mph. I can't change the noise by swerving and I can't hear anything grinding when jacking up the truck up while spinning the tires by hand. I'm just over 77,000 miles with new tires 5000 miles ago, I just rotated the tires and the noise didn't change or move. The rear diff is up to level and has been changed 5 times already. This is my DD so no harsh off-roading, just forest roads to get to hunting and fishing spots. I do have the diff howl/whine and that's still there, the new noise is about the same level in the cab but it's constant at highway speeds. I'm leaving for a short vacation Tuesday that will be about 600 miles round trip, do I trust it or take the wife's car but then we can't bring the bikes?

 

Any play in the carrier bearing?

 

Good thought, but the carrier bearing feels just fine.

 

It’s probably just those new tires.

 

Dang. Worth a try!

Yeah, you're probably right.

@crashnrondo, are these new tires the exact same as the last set or a different make, model, or size? How are your shocks? I think dying shocks can let tires cup and that can cause noise at speed.

 

I'm 99% sure the noise isn't the tires, all 4 are nice and smooth with no cupping or feathering. My old tires wore very evenly and looked good when I pulled them off, unfortunately I sold them so I can't try them. Shocks are new 4600's last fall, tires and rims are new take offs from a 2023 Sport with less than 50 miles, so not the same as my old tires/rims. I've never had a bearing go bad except a front one on my wife's Rav4, that I could change the pitch by swerving. Not sure with the rear solid axle works the same way.