We purchased the vehicle in the title with 158k miles. 4x4. Excellent shape. I started noticing starting at 55 mph up to 65 I am hearing a humming noise. Sounds like its coming from the front. Haven't checked the wheel bearings yet. Wheels are 22" and tires at dated but what gets me confused is when I slightly let off, the noise goes away. Back on the fuel, noise returns. Cruise set coasting down hill the noise goes away. I think I have heard it quickly slowing down also.
The only thing i have done so far is changed engine oil and drained and refilled transfercase. Noise was there before I did any of that. At first I thought it was tires but letting off the gas and the noise going away has me confused.
I have seen other people talk about engine pulleys and tensioners which could make sense due to torque load on the system. If I had to pick a direction, I would head to the front passenger side but I know how noise can transfer. I am going to be looking at everything here in the next few days. Appreciate any input on where to start.
I should also note that the noise isn't extremely loud. Just concerning. I can turn the radio on a bit and drowned it out.

 

Tire noise won't go away letting off the pedal, so it's either your front differential or your wheel bearings. I'd put it up on stands and check for any weird noises, and/or pull your front differential case cover and see what it looks like. I don't know if you bought this vehicle used, it sounds like it, but lots of people don't change the axle lubricants like they should. If it's never been changed, then all the metal that accumulates during the break-in period is still inside your axle, causing wear and tear.

 

Yes the vehicle was bought new. I will have to do some more checking. I didn't think it was tires because of that same reason. Would the front cause that type of noise though not being loaded in 4x4 and just floating down the road? Haven't tried in 4x4.
if the front case oil has never been changed i could probably drain and refill but at that point its probably trashed.
Just don't want to chase issues. I have thought the front before with stuff like this and then found the noise was transferring through the aluminum drive up from the rear.

 

It wouldn't hurt to change out the front differential lube and put in some synthetic 75-90w lubricant. I don't know if it will help, but at the age of your vehicle it should be done, front and back. Do it when they are warm/hot. Lots of times you can reuse the cover gaskets too, but they are cheap. You dont know that they are trashed as it could be something else, but at the age of your vehicle they should be done.

 

Just looking at any fluid's color is a big indicator of what's going on inside. Especially at your mileage. Popping off the fill plug is an easy quick check.
Front diff. is super easy with both fill and drain plugs.

 

Had some time this past week and dropped the front differential fluid. Dark but pretty much clear of metal. Nothing much to speak of on the magnet. It was also due for tires so those were done. Noise is still there.
No play in the wheel bearings but they look newer. Wondering if they were cheap aftermarket or maybe over tightened.

 

Hiperf2007, I have go exactly the same issue as yours recently, its been a few months, the sound is getting a little worse. Dealership is of no help. Visited two repair shops, first one told me they suspected the flapper valve, so I went to a muffler shop and they said yes it is that valve bad, they removed it, sound is till there. Second shop said my torque converter bad, asked over $4000. I didn’t let them do it as I don’t afford the $4K and no one can promise the pins would be gone after the torque converter replacement. It is super frustrating. How do you fix it eventually?

 

Hiperf2007, I have go exactly the same issue as yours recently, its been a few months, the sound is getting a little worse. Dealership is of no help. Visited two repair shops, first one told me they suspected the flapper valve, so I went to a muffler shop and they said yes it is that valve bad, they removed it, sound is till there. Second shop said my torque converter bad, asked over $4000. I didn’t let them do it as I don’t afford the $4K and no one can promise the pins would be gone after the torque converter replacement. It is super frustrating. How do you fix it eventually?

 

I believe it's a worn rear end. I did a fluid swap with Mobil 75w90 full sync and the noise dropped to almost nothing but came back slowly after a few months. I might try some noise reduction additive on the next change.
To me it sounds like a worn pattern on the teeth causing the noise. Wife has been driving it for the past 8 months. I don't think the noise is as bad as it since I did a fluid change though.

 

Thank you so much for your reply. The rear end was serviced in April this year. It still could be its issue. Here is some more information about the weird sound,
It usually doesn’t happen when below 40 mpg,
It doesn’t happen when coasting,
It doesn’t happen when push hard the gas to speed up,
It doesn’t happen at idle, parking or neutral.
It happens only when pushing the gas slightly, it looks like a specific point, only when pushing the gas at that point, it makes the sounds, and I can feel the vibration.
Now there has been shakes when accelerating.
yesterday the mechanic said it might be the torque converter and he asked $4000+ to replace it. A big decision A big money. The thing is, they don’t guarantee any fix.