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, 201412 yr by BigMattyD

Edited February 22, 201412 yr by heartless

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

Edited February 22, 201412 yr by heartless

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.  

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.

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

 

Mine was the opposite, so they can fool you.

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.

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. 

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.