High pitched Hum Sound

[jeeplib05]

I've got a buddy of mine that just got a 05 Libby with about 170,000 miles. Whenever he uses the cruise control, or has his gas pedal set on a certain speed, there's a high pitch hum/whining noise. You can pretty well hear it from every speed from about 35-65 MPH, but from there up it goes away. The oddest part of it all, is that if the steering begins to go to the left (say, driving down the highway and curving to the left), the whining gets gradually louder the more the wheel is turned, but if the steering wheel is going to the right, no sound. So as you're driving down the road, correcting your wheel to stay going straight, for example, it'll make the faint noise. Curve to the left and it's loud, curve to the right and it stops. Any ideas?

**hard to explain, sorry if it's confusing**

 

[Lancer]

I'd say wheel bearing, but I can't recall which one, I think front right.

 

[tommudd]

Check right front wheel bearing first
turning right puts more pressure on that one so quiets the noise some

 

[M38 Bob]

Definitely (from your description) a wheel bearing. Unfortunately, each bearing/hub assy has an inner and an outer, so inner on one side will get louder cut in one direction. Outer on the same side will howl louder cut in the other direction. You've got to try and pinpoint the sound from it's apparent location instead of which way it seems loudest. Often(though not always) there will be some up and down play in the bad bearing when you jack em up and work them up and down.

In our shop we try to get the customer to decide "which side". That way if they're wrong we charge labor to put the good removed bearing back on the other, defective, side. If we guess wrong I eat the additional labor.

Bob

 

[tommudd]

With KJs having basically one sealed bearing its a lot harder these days than what it used to be when we had inner and outer bearings

 

[M38 Bob]

With KJs having basically one sealed bearing its a lot harder these days than what it used to be when we had inner and outer bearings

But Tom, there is an "inner" and "outer" bearing. They're both inside the hub assy with the spindle riding on them.

Bob

 

[jeeplib05]

Thanks for the replies,

As you drive it down the road M38 Bob it sounds like it's coming from the right side. When you turn the wheel to the left (especially on the highway) it gets much louder, turn it to the right and it almost goes away

 

[tommudd]

But Tom, there is an "inner" and "outer" bearing. They're both inside the hub assy with the spindle riding on them.

Bob

Shaking head...............
Yes I know what you are saying, but it is unlike the ones from years ago that the bearings were further apart and could be more easily diagnosed is the point I was making.

 

[HoosierJeeper]

I think the best way to check is to jack it up and looks for play. And you'll just replace the whole bearing/hub assembly, it's all one unit.

 

[tommudd]

Mine in the 04 were bad , but no play at all, good and tight when I kept looking for a noise. Ruled out the wheel bearings at first then went back to them after everything else checked out.
Just like rear u-joints, can feel tight but rusted tight and making noise like no tomorrow. Just heard one yesterday on a KJ in traffic, wanted to stop the lady and tell her to replace the dang u-joints ......:icon_lol::icon_lol:

 

[M38 Bob]

wanted to stop the lady and tell her to replace the dang u-joints ......

Yep, very distinctive sound.

Bob

 

[jeeplib05]

So is it the bearing or rear u-joints? Sorry I'm new to all of this..

 

[M38 Bob]

Yours would definitely be a wheel bearing. Ujoint noise comes at really slow speeds.

Bob

 

[dude1116]

Yours would definitely be a wheel bearing. Ujoint noise comes at really slow speeds.

Bob

Or high torques. Although arguable pinion angles can do the same.