Front end Humming (Alignment?)

[Barnes888]

Hey guys, was wondering if anyone could perhaps give me any ideas on what would cause my 2003 Gmc Sonoma (4x4, non-ZR2) to hum in the front end. The Balljoints have about 70,000kms on them (Moog) and i'm running 31" All-Terrians which are in good shape. It kinda sounds like i'm running a Mud-Terrian on the front left wheel.. and the noise seems to get louder when i turn right.. at anything over 40km/h.

I was thinking maybe the CV is gone.. or Ball Joints. Gonna jack the truck up tonight and check the Ball Joints.. but if anyone could give me some idea or anything else to check. that would be excellent.. Thanks!

[maxwedge]

Most likely the ft wheel bearing based on you description, nothing else you mention would cause this. Of course make sure that tire is not scalloped or worn unevenly, if so switch them lt to rt see if the noise moves.

[Barnes888]

hmm well i'm gonna rule out the wheel bearing idea.. since its 4x4 and had CV shafts in the front..

[blazee]

Originally Posted by Barnes888

hmm well i'm gonna rule out the wheel bearing idea.. since its 4x4 and had CV shafts in the front..

You still have wheel bearings on the front of your 4x4. They come has a wheel bearing/hub unit. The unit bolts to your steering knuckle, and then the CV half shaft slips through the center and is held tight with a 36mm axle nut. The center of hub bearing is splined as is the half shaft in order to transfer power from the front differential to the tire.

Based on your description the bearing is the most likely cause of your hum. As the bearing goes out, it starts to hum and later turns into a growl which will be accompanied by a vibration. The reason it gets louder when you turn right is simple, the vehicle's inertia wants to keep going staight, when turning to the right the weight of the vehicle is transfered to the left side, which loads up and puts more strain on the wheel bearing.

Here's a picture of the unit:

[maxwedge]

H'mm I thought we'd rule out 4x4 wheel bearings. LOL