Need help diagnosing noise/vibration

[sasha055]

Hi,
I have a noise and a vibration from the rear of the car going that drives me crazy. Here are the symptoms:
Noise: wheel bearing like noise, it feels sounds like a small rock is caught in the tire.
I did a wheel bearing test and if I turn right noise almost dissapears, if I turn left it's getting louder.
I can hear noise only at 45-60mph, slower then 45mph there is no noise, faster then 60mph tire noise covers everything.
Vibration: it's small.. again it feels like a small rock is caught in the tire and I can feel it, vibration is consistent througout the speed

Obvious diagnosis is rear left wheel bearing, however I changed it 2 times already and noise/vibration is still there, it feels better first few days after I change the bearing then it's getting worse. And by better I mean it's still there just not as prominent.
Car is 2000 base boxster with 72K miles and 18" factory wheels (no spacers).
I also aligned/balanced the tires a couple of times.

What else should I check... it's driving me crazy!

Thanks
Sasha

PS: there is no rock caught in the tire

[thstone]

My first guess would be to look carefully at the rear driveshafts and CV-joints. Might have a CV-joint bound up or starting to fail.

[SeanZ4]

+1 on the cv joint. The fact that the noise changes when you turn or alter your speed kind of made me think about the cv too!

sean

[sasha055]

What should I look for in a CV joint?

The boots are in perfect condition.. how would I diagnose a bad CV joint?

Thanks
Sasha

[Perfectlap]

I hit a massive pot hole over the weekend and a day or two later I end up with a big virbration under 60 mph that seems to lessen significantly once I'm at speed. At first I thought I had a tire issue so I pulled over, no problems with the tires. Somehow I got home without any drama. I bent something didn't I?

[jcb986]

Also check for bad motor mounts....

[sasha055]

I replaced front motor mount 2k miles ago...

Any tips on what to look for when shopping for axle? is left/right interchangeable?
Are pre2000 axles different from 2000+ year?
Anyone has a suggestion on where to get one? (except pelicanparts 800$ is out of question right now)

Thanks
Sasha