Drivetrain howling

[Matahoe]

I am hearing a whirring noise consistent with wheel speed. The pitch of the sound stays the same regardless of which gear I am in but will go up and down depending on what speed I am going.

It doesn't seem serious at the moment (fluids are good and no metal grinding) but was wondering if anyone can help me pinpoint a common area I should be concentrating my troubleshooting on.

 

[oldchev]

Assuming its all wheel drive or 4 wheel drive my reply is this, I see you are at 163K miles and since the sounds is consistent with speed and not gear selection I would start with the front differential. If you don't know when it was last serviced if ever then drain that fluid. It will no doubt be a silver color from bearing wear (common). Look at the magnetic drain plug for larger chunks of metal. It will probably have a muddy metallic goo on it which it bearing wear also. Depending on findings we can go from there.
Another possibility is the front hub bearings could be worn also, Does it howl more on turns or straight?
Then there is the "half shafts" that have cv joints that could be worn.
There are other areas to consider but based on cumulative reports from other users I would start there and eliminate items.
Lets us know what type of drive train you have.
-OldChev

 

[Matahoe]

Its an LT 4x4.

The sound is noticeable from 35 -65 mph. From my early days as a shadetree mech I remember reading somewhere that noise at this speed range indicates a specific drivetrain issue. But I cant remember what it was. The troubleshooting step was in an old Chilton manual or something.

Anyway...judging by the relatively low volume of the noise Idont think it speaks impending disaster just yet.

The front diff fluid was changed a year ago and a year before that with either Valvoline or Mobile 1 65w-90 synthetics. The first time I changed it there was no metal, neither was it silvery in color. It looked fine to me...just a bit dark iirc.

 

[corvette744]

Its an LT 4x4.

The sound is noticeable from 35 -65 mph. From my early days as a shadetree mech I remember reading somewhere that noise at this speed range indicates a specific drivetrain issue. But I cant remember what it was. The troubleshooting step was in an old Chilton manual or something.

Anyway...judging by the relatively low volume of the noise Idont think it speaks impending disaster just yet.

The front diff fluid was changed a year ago and a year before that with either Valvoline or Mobile 1 65w-90 synthetics. The first time I changed it there was no metal, neither was it silvery in color. It looked fine to me...just a bit dark iirc.

So when your driving 55mph lets say and you switch lanes left to right does the noise change from throwing the steering wheel left to right..If it does im betting hub bearing.

 

[rockola1971]

If its the hub its most likely the driver side. Jack front wheels just off the ground and grab tire at 9 and 3 oclock and rock it. If its bad youll feel it. Turn tire and feel for a gritty rotational feeling instead of a smooth rotation feel.

 

[chrispitude]

I am hearing a whirring noise consistent with wheel speed. The pitch of the sound stays the same regardless of which gear I am in but will go up and down depending on what speed I am going.

It doesn't seem serious at the moment (fluids are good and no metal grinding) but was wondering if anyone can help me pinpoint a common area I should be concentrating my troubleshooting on.

2006 Yukon XL Denali owner here. I'm debugging a similar noise. It's quite noticeable at highway speed in any gear. However, if I put the transmission in neutral on the highway and rev the engine to the same RPM, there is no noise. It only happens when the drivetrain is transmitting power (even just barely maintaining highway speed).

Does your noise behave the same way?

 

[Matahoe]

It only makes noise when in 4wd or Auto 4wd. worse in 4wd. No change in whirring noise regardless if vehicle is coasting or under load.

Now i am hearing a slight grinding noise in my drivers side hub area when turning left in parking lots. Also hearing a dull thump thump noise going over bumps. So I am going to check that out now. Its probably ..most likely the hub bearing.