When driving at speeds higher than 30mph, my Jeep makes a deep humming noise. Recently, I drove a curvy canyon highway and I noticed that the noise would vanish when ever I was in a right turn and return as soon as I straightened out. Left hand turns, the noise seemed pretty consistent. I'm wondering what this could possibly be? Axle u-joints? Unit bearings?

 

Could be either of those. My guess would be a wheel bearing. Jack up the front and and see if there is any forward and backward play when you grab the wheel at 12 and 6. Could also be a u-joint, look for red dust on the ujoint or get a pry bar in there and feel for play.

Use the search function to find a more detailed explanation on how to test each of those.

 

Could be the right side front hub bearing. In a right turn the load is on the left side.

Max

 

Okay, thanks guys, I'll see what I can find.

 

Well, I couldn't tell much on the unit bearings. What's the best way to tell? On the right side U-joint there was a tiny bit of play in the inside shaft's ear, maybe a thousandth of inch. Is that enough to cause a problem? The left side didn't have any play.

 

That's classic wheel bearing fail. U-joints don't know left turns from right, but wheel bearings do. If the $$ isn't an issue, change them as a pair. If one has failed the other is probably not far behind.

You could put the front up on jack stands and spin the front wheels by hand, feeling for any grittiness and listening for noise. Then grab each tire at 12/6 o'clock and see if there's any slop as you push/pull alternately on the top and bottom of the tire. Don't be surprised if you don't find anything, often they'll start singing before you can detect the failure manually.

 

Thanks for the info guys, nice to figure out what that noise is.

 

I second this.

 

Pretty certain its the right side front wheel now, thanks for the help. Is there a certain brand that makes a good replacement, been thinking either Timken or Moog. Checked out the Mopar from one source, I just can't justify that much of a price jump.

 

Timken would be my first choice.