I have had a sound from the rear becoming louder with time (or maybe with cooler temps) that I cannot figure out. It is not terribly loud so it can only be heard when off the gas (so I may have missed it for a long time).

It is a squeaking/scraping/whirring sound from the rear that is in sync with wheel rotation. It is fairly high pitched and seems to be brought on by taking a turn. It continues after a turn but abates after a minute or so and seems to disappear until the next turn. It is present in neutral so probably not associated with the drive shaft.

It sounds kinda like a brake hanging but I have checked and they seem to be fine. I have checked the diff and it is full of clean lube (mobil 1). The CV boots look fine and there is no evidence of leaks. There is no evidence of scraping.

If I put the car up on stands and run it (up to about an indicated 50 or so) there are no unusual sounds. It is quiet after putting it back down and driving to the first turn when the noise comes back.

I will continue to drive it until something breaks but would like to head that off.. besides the noise being very irritating. Any experience with this?

 

No experience with the S2000, but on other cars, it was a wheel bearing. Turning can add extra load to the bearing. Have you checked the torque on the hub nut lately?

 

Thanks, thats a good point. I look into it tomorrow.

I have a 36mm socket, I hope that's the size. As I recall the torque spec was revised.. do you remember what it is? Any tips?

 

Yes, a 36mm axle nut socket will do the trick. The OEM torque was 181, now revised to 220.

 

Sounds like a questionable wheel bearing to me.

 

The hub nuts were tight and retorquing had no affect.

Anyone know if wheel bearing replacement is quick? Does the knuckle have to come off?

 

Well, with that wheel in the air, grab either side of the tire and "wiggle" it - push in and out. If there's freeplay, and you don't see the suspension/brake components moving as well, then it's a wheel bearing. If not, then the wheel bearing should be fine.

 

The Acura dealer that replaced mine indicated that the knuckle had to be removed to change the bearing. Watch out for the ABS sensor, too - they damaged mine during the bearing replacement. It may be that it's damned difficult to NOT damage it but I wasn't happy to pick up the car only to find out the sensor was not working.

BTW, while my symptoms weren't quite as you describe, I'd agree that it's likely to be the bearing. A retorque helped for a week or two but returned rather quickly...

 

I just replaced a rear wheel bearing last week. You do have to remove the knuckle. I've got a decent assortment of bearing/hub drivers, and hammered the old bearing out, and pressed the new one in.

The bearing is a sealed double row ball bearing, and a bit more difficult to swap than a non sealed Timken/roller bearing.

For a wheel bearing to fail the wiggle test, it has to be pretty shot. Most will make noise long before they have axial play.

 

But a lot of times tire noise, or engine/exhaust noise will cover up a noisy wheel bearing.