Humming sound on left turn

[BigMattyD]

Here are the details:

 

2003 Outback Wagon, AT.  166,000 miles

 

Recently, there has been a pronounced humming noise and mild vibration, only when at speed above 40 mph and turning steering wheel to left side.  Any magnitude of left steering causes this hum.  When I go perfectly straight or to the right, there is no hum.  

 

The humming frequency changes with wheel speed but not engine speed.  It is a mild, low frequency hum that sounds like rough pavement or tire hum, (kind of like a knobby tire or something).  It is a noise that sounds like it is coming from the front of the car, but also a mild vibration felt in the floor of the vehicle and the steering wheel.

 

Additional info:

 

Right side inner drive axle boot is torn, and axle has been clicking mildly on steep right turns.

 

All 4 tires just replaced.  Noise is the same with the old or new tires.  Wheel alignment was just done at time of tire replacement.  No difference.

 

A few weeks ago I had a NY state inspection.  No issues noted RE: loose suspension components (ball joint, tie rod, etc.)

 

I feel I should be looking for either worn suspension or steering parts or maybe a bad wheel bearing.  Can anyone give me any further direction?

 

Matt

Edited February 22, 2014 by BigMattyD

[heartless]

Edited February 22, 2014 by heartless

[BigMattyD]

Yes, as I search through similar threads, that is what I am seeing.  

[heartless]

Edited February 22, 2014 by heartless

[BigMattyD]

Thanks a lot, I will take a look at it when I get home.  I will try spinning the wheels and feeling or listening for grinding.  I have a stethoscope that might help.  

[1 Lucky Texan]

Even though soob bearings can have mysterious failure modes, what you describe is one common way a right (probably front right) wheel bearing could begin to fail.

 

certainly have other components check/replaced as mentioned.

 

an infrared remote thermometer might show one bearing/hub 30 degrees hotter than it's mate after a highway run.

[CNY_Dave]

Typically the bad bearing gets noisier when on the outside of the turn.

 

Mine was the opposite, so they can fool you.

[BigMattyD]

While driving, the sound comes from the front but I can't tell which side.  after I got home, I felt all 4 hubs, inside whe wheel.  Basically, the center part of the brake rotor.  The only one that was noticeably warmer was the front left. 

 

I have not jacked up the car to check the bearing noise for sure yet, but I think I may be on to it.  It is hard though, to be sure that the extra heat on the left wasnt due to a draggy brake pad or something else.

[BigMattyD]

I have a harbor freight 12 ton shop press that I can use.  Is pressing a bearing out and in something I can handle, if I take the whole steering knuckle off?

 

I dont have any of the subaru special bearing tools. 

[CNY_Dave]

If you have a bunch of collars, spacers, big sockets, etc you can press it.

 

I had no special tools other than the press, and an awareness that for the new bearing you have to avoid pressing such that any force is transferred through the bearing- all force to the outer shell itself.