So I’ve been trying to hunt down this faint grinding sound coming from the front left axle area for a couple months now. I took it to a shop and was told it was my hubs so I replaced them with Timken hubs, did the sound go away? Nope.
So I took it to another shop and the test drove it and said they could not hear anything. Well my wife can hear it and she’s not mechanically inclined at all, in fact she said she thought it was the brakes (it’s not) and thought it was normal. I only ever hear it at very low speeds mostly. I’ve checked the IWE solenoid and it’s good, vacuum is good too.

Now back to the reason why I’m posting this… so today I threw it in 4A since I only keep it in 2wd just for ****s and giggles. Then I navigated to the off road page and power distribution page and noticed power going to the front when there was no loss of traction. Is this normal because I know when in 4A it only sends power to the front wheels when there is a loss of traction.

 

Pretty sure mine sends some power to fronts as well. Just more to backs unless needed.

Did the sound go away in 4A?

 

unfortunately it did not

 

Mine shows a small amount of power going to the front under most conditions.

 

Same as the others. When in 4A it's like your truck is in AWD mode. Your front wheels are powered slightly no matter the traction.

The grinding you hear should be inspected. It could be a small job like the IWE or wheel wheel bearings or it could be something worse in the 4x4 pumpkin area.