Wheel Hum

[ShadowFist]

I just got a 99 cobra and the only real problem that I see is that at speeds above 25 mph there is a hum coming from the front right wheel. It gets variably louder at higher speeds, and tapers off around 60-65 (but comes back again at 70). I have changed the tire with a different set, and the problem persists. Any ideas?

 

[missouri_guy197]

Possibly a warped rotor...do you feel any steering wheel vibration with it?

 

[tomustang]

Possibly a warped rotor...do you feel any steering wheel vibration with it?

there was a huge debate in the 4.6L section that rotors do not warp

 

[wythors]

A warped rotor won't make noise. It will cause a vibration under braking. My suggestion is a wheel bearing.

 

[69 Rustang]

Second on the wheel bearings--replace them and the races, the hum will likely go away.

 

[ShadowFist]

No steering vibration... We had a good idea that it was the bearings, but when we pulled off the tire and grease cap, we found that it was a different bearing setup than everything else we had seen. We checked a Chiltons for a 96-98 cobra, and it had the same/similar setup there. They say that the entire assembly will have to be replaced if it is bad.

Is there a surefire way to see if it needs to be replaced?

 

[d90212]

3rd on the wheel bearing. its a sealed non serviceable unit that does occasionally go out.

 

[Price1]

Check to see if the "hum" lessens or goes away when you turn one direction or the other. If so, it's definitely a wheel bearing as others have previously mentioned. I had the same thing on my car last fall. Replaced with an Autozone hub and noise is all gone. You simply cannot tell by looking at them whether a wheel bearing is bad or not.

Yes, it's a sealed hub/bearing unit and costs around $50+ at Autozone.

Good luck....

 

[ShadowFist]

Is this something that would require replacing both front units or does replacing just the one work fine?

 

[wythors]

One will be fine. Do it soon.

 

[69 Rustang]

I had an 86 GT years ago and lost it in the snow--popped a curb with the right front. It wasn't enough to damage the wheel, but I had a distinct hum for several weeks exactly as you describe--above 25-30 on up and hmmmmmmmmmmmm........ Replaced the bearings and back to normal. You said you just got the car--maybe someone hit something before you got it, but I wouldn't wait to fix it.