All,   I have been chasing this issue for a few months,  2 different mechanics and the problem is still there.   The car is a 2006 Legacy Outback Wagon 2.5 Auto with about 160K on it.

What I have is a rumble that starts at about 40 MPH.  It does not change in pitch. I have had the right front wheel bearing replaced,  the driveshaft replaced, center bearing was toast, rotated the tires front to back in case of cupping, drove the car and did a temp test on the bearings all around the car,  temps were within10 degrees of each other.  Several years ago I had both front axels replaced with aftermarket life time warranty axels from a parts store.  I keep an eye on the diff oil, still clear and full on the dipstick.  The diff oil was changed several years ago when I had the axels put in. The tires are Nokias at about 40% wear left, with cupping starting to show.

The car drives perfectly, no binding or vibrations.  Just this friggin noise. 

Todays project is pulling out the spare and putting that on the right front and see if the noise goes away.  I may even bring the snow tires out and put 2 of them on the front and see what happens.

Any suggestions are welcome,    Mark

 

3 hours ago, foxgap said:

The tires are Nokias at about 40% wear left, with cupping starting to show.

my money is on the tires... does not take much cupping wear to make noise, and by the time you can actually see it, it has been around awhile.

Thanks heartless,  I am going to get a set of tires for spring.  But this is what I found out this morning.

I put the spare tire on the right front after checking to make sure the tire pressure was correct, took the car for a ride and the rumble is still there but at a different pitch.  I think it is because it is a much thinner tire than the stock size.

Then I put two snow tires on the front and took it for a ride again, pitch of rumble has again changed.  Probably from the aggressive tread pattern of the snow tires.

So the summer tires are back on again and I am no further to answer than I was this morning when I first posted. 

lifetime warranty or lifetime of replacing with aftermarket axles from what is reported hereabouts.

swap the front tires R to L and see if the rumble follows the tire.

probably best replacing tires as you plan and then start looking for demonic possession if symptoms persist. In the meantime, turn up the radio.

common things happen most commonly.

Alignment.  Probably been done but don’t see it mentioned.

Aftermarket axles are garbage.  All of them. Numerous issues I don’t have time to type it all out or share the horror stories or why it’s not as commonly known. 

It is interesting the tire changed the noise. Different load on those trash axles and it couldn’t take it. 

Used Subaru axles with new Subaru boots are far superior to aftermarket. Probably can get away with aftermarket boots if you’re not in an extreme environment.  Ours see winter road salt and chemicals and degrade faster than Subaru boots. I’m assuming the chemicals degrade them faster just based on what I know about materials science and seeing them fail sooner so I may be wrong. But they can fail in 5 years instead of 10. Might not matter to some so aftermarket is probably reasonable for boots for some people. Subaru axles last the life of the vehicle and should never be replaced. Shops just do it because it’s easier and the make the same money as a reboot. 

it's a fair amount of work but, axles will swap L to R. maybe see if the sound follows. (while you'rs doing that , check the axle nut is tight I guess.)

Thanks Guys,  an alignment was done at the time of new tires.  I am going to start hunting for a set a Subaru axels to reboot.  I had problems with aftermarket axels before but they usually just clicked, no rumble but anything is possible with that crap I guess.    

On 8/29/2022 at 5:15 AM, foxgap said:

Thanks Guys,  an alignment was done at the time of new tires.  I am going to start hunting for a set a Subaru axels to reboot.  I had problems with aftermarket axels before but they usually just clicked, no rumble but anything is possible with that crap I guess.    

if the inner joint fails, they usually won't click.  You usually just get a bad vibration

1 hour ago, Daskuppler said:

if the inner joint fails, they usually won't click.  You usually just get a bad vibration

Yep - if they do make noise it'll be facing up a steep hill, from a stop making a right or left turn with steering wheel at full lock and accelerating up hill through that turn.  It'll be a deeper knock knock as opposed to the outer joint click clicks. 

HUGE UPDATE.

After 2 years of whines and now a loud rumble I took the car to yet another mechanic.  This time he is a retired tire and suspension guy and he diagnosed the problem an old school way.  We took the car out on a back road with a hill, he sat in the back seat and as we started down the hill I popped the car in neutral and shut off the engine.  Bingo, right rear wheel bearing screaming away.  Yesterday he replaced it and the car is now stone quiet, well a little noise from the cupped tires, but I can live with that till the new ones come in the spring when I take the snow tires off. 

Thanks for all the comments, you guys are great!

Mark

2 years - wow, that's got to feel good to be done with that!  With those extra parts replaced maybe you can keep those annual PA inspections at bay for awhile (if those are state wide?)

If the title didn't say front, we would have landed on rear wheel bearings first since that's by far the most common issue on 2006 Outbacks. 05-06's have an extended 100,000 mile/8year rear bearing warranty because of it. Very well known. The title saying "Front" steered us wrong. Otherwise this would have been easy for folks very familiar with Subaru's due to that issue.  I say all that because it would be good to keep that in mind for the other side. Even if they've already been replaced after 15 years if they were aftermarket, that's just as bad, if not worse. I just replaced the same exact part number as yours in a 2008 rear. It was already replaced with aftermarket 14 months ago and already failing.  And that's not the first time I've seen that. I've never seen a replaced Subaru bearing fail. 

May have had multiple issues - the title said "rumble", now described as "screaming", and it says front when it was rear. That's really odd to mistaken front/rear for a noise. I don't have good hearing, usually working on older/noisy cars and we have horrendous roads and i still never even remotely confuse front/rear.  You may have had one failure, the wheel bearing, and maybe some other noisy components too.  

 

did that wheel rock up and down at all? or just had the noise?

5 hours ago, idosubaru said:

was already replaced with aftermarket 14 months ago and already failing

yup, aftermarket wheel bearings - even decent name ones - are generally 2 yrs or less on a daily driver... if you dont drive the vehicle every day, you might get longer..

The first 2 mechanics swore it was in the front and I did have the front right replaced.  It took an 82 year old retired mechanic 15 min to diagnose the right rear.   The rear wheel had NO symptoms of wheel bearing problem other than a noise everyone swore was coming from the front.   Sometimes two heads working on the problem are better than one.  

vibration in the seat bottom is also an indication of rear wheel problems.

13 minutes ago, lmdew said:

vibration in the seat bottom is also an indication of rear wheel problems.

or "bad gas"?

14 hours ago, foxgap said:

The first 2 mechanics swore it was in the front and I did have the front right replaced.  It took an 82 year old retired mechanic 15 min to diagnose the right rear.   The rear wheel had NO symptoms of wheel bearing problem other than a noise everyone swore was coming from the front.   Sometimes two heads working on the problem are better than one.  

Subarus (and probably others I just don't know) are well known for passing any wheel bearing test. There's no one test that positively identifies all failing wheel bearings.

11 hours ago, brus brother said:

or "bad gas"?

Did you ever have a client have that issue while you were working on them!?