New hum while driving.

[Elan_]

My truck seems to have developed some sort of hum while driving. It sounds the same as mud tires on the highway. But I've had these KO2s for months and they've never hummed. I've recently greased the drive train and replaced the driver's side CV half shaft but the hum didn't start right when I did those things. I drove it about 600 miles the day before the hum started and did a bit of light offroading.

What could the problem be? 2006 V8

 

[nevada]

My truck seems to have developed some sort of hum while driving. It sounds the same as mud tires on the highway. But I've had these KO2s for months and they've never hummed. I've recently greased the drive train and replaced the driver's side CV half shaft but the hum didn't start right when I did those things. I drove it about 600 miles the day before the hum started and did a bit of light offroading.

What could the problem be? 2006 V8

a bearing of some kind. probably a wheel bearing, but you would have to isolate it to be sure.

SOMETIMES you can jack it up and shake the tire, it may move if its bad.
however, I have seen it MANY times where the bearing is bad, but is still tight. much harder to verify it.
usually need a stethoscope, and run it in gear, then listen to each bearing position. you will be able to hear the difference.

 

[rblt]

My truck seems to have developed some sort of hum while driving. It sounds the same as mud tires on the highway. But I've had these KO2s for months and they've never hummed. I've recently greased the drive train and replaced the driver's side CV half shaft but the hum didn't start right when I did those things. I drove it about 600 miles the day before the hum started and did a bit of light offroading.

What could the problem be? 2006 V8

Perhaps a wheel bearing? Reading your post reminds me of when I put a set of Nokien WRG3s on an HHR, after which there was a significant "hum" but no vibration, etc.
I assumed the Nokiens produced a lot of road noise ( also had read some reviews to that effect).

Several months later, while getting the front brakes done, the tech found a bad front driver side wheel bearing. Once replaced there was virtually no road noise.

 

[Elan750]

A couple other common characteristics of wheel bearings-

gets louder as you go faster.

can often go away during a hard turn. Left bearings often get quiet on hard right turns, right bearings on left turns.... or was it the other way around... one bad one I had would become completely quiet on highway exits.

They can also go bad quickly if you overtorque the axle... just a thought

eventually the wheel will get looser, and you will feel vibration0- thats when it starts to be unsafe.