noisy tires, or something more serious?

Hi all. I've had my 2005 Legacy for a couple of years now, and it's still got the same tires the dealer put on it when I bought it used from him. They're Republic Enterprise tires, which have great grip in the rain and snow, but they've gotten really noisy in the past year or so. I've probably driven less than 10k miles on them, so they've got plenty of tread. They weren't very noisy when I first got them, but now they're so bad that my kids hold their ears whenever I get up above about 50 mph cause the whole car seems to hum and resonate. Luckily I don't take the kids in it often, and it's just used for short drives to work, where I don't go above 55mph. Taking this thing on the interstate last week at 70mph for 20 minutes almost made me go deaf.

 

The humming is directly related to the speed of the car, and not the engine RPM or braking. The sound seems to only be from the rear tires. But the weird thing is that the noise stops when going around a right turn, even a very slight right turn. The noise stays the same when going straight or turning left.

 

Is there something else that could be causing the noise besides the tires? I was thinking that putting some nicer tires on it would make the humming go away, but now I'm starting to think maybe there's something else to blame. Any ideas? Thanks.

Could be rear wheel bearings which is a common failure on Subaru's. Rotate the tires to possibly eliminate the tires as being the cause.

Yep, sounds like bearings to me. I did some reading this morning on the forum about the bearing issues, then went out and checked all 4 wheels. The rear passenger side wobbled noticeably with my hands at about 2-oclock and 8-oclock. I'll try to get it to a dealer to check it out further. I never got it looked at after receiving the letter about the bearing issues last year.

If the noise goes away when going around a corner in one direction but does change or gets louder when going the other way, it is almost certainly a wheel bearing, which was verified by shaking down the suspension.

i think i have this hum too... not too serious though... so does the bearing issue do any damages to the car?

i think i have this hum too... not too serious though... so does the bearing issue do any damages to the car?

The wheel bearings support the full weight of your car... I'll let you decide what to do.

a bad wheel bearing is a serious safety concern.

 

a wheel bearing can be bad without having any play. one way to find out is to jack the car up and spin the wheel that you think has the bad bearing. while spinning the wheel, grab your spring with your free hand. you will feel a noticeable "grit" if the bearing is bad. Compare with the opposite side if you are unsure of what you are feeling. there should be an obvious difference between the two if you indeed have a bad wheel bearing.

I finally got the car to the dealer yesterday and they replaced the right rear wheel bearing. Holy cow, what a difference! The car is amazingly quiet now, something it hasn't been in a very long time. So if anybody has a hum coming from their rear wheels, get the bearings replaced, it's heavenly to have a quiet car now!

Hopefully you got them done under warranty, they are still covered up to 8 years.

Yep, I'm at 90K miles, so I'm glad I got them done before 100k. It was the first time in 10 years I've ever gotten anything done for free, cause I've always bought used cars that were past their warranties. It was a great feeling to see the invoice say $0.00 when I went to pick it up. Even did a free state inspection ($16 value) and the ECM reprograming recall.