Howling

[Ptool2000]

Time for my first post. I tried searching for a similar problem on here, but came up empty. Have 98 AWD and it has a slight howling noise that seems to come from the front end. Seems to start around 15mph and remains constant until road noise drowns it out. I let it coast in neutral to eliminate a motor noise(not effected by RPM's) and tapping the brakes has no effect. Where should I look? I know wheel bearings can grind when going out, but squeal?

 

[my98nnj]

Tires, Wheel Bearings, Brakes, Front Differential all need to be checked to pin point what's making the noise.

 

[BrooklynBay]

Welcome to this forum! Put the vehicle on a repair lift, then put it into neutral, and turn the front wheels to check for the location of the noise.

 

[Ptool2000]

I'll give that a try. What is the best method to check wheel bearings?

 

[windsors03cobra]

Check for up and down slop with the wheel on, if none take off the wheel and brakes and look for rust/corosion dust where the bearing meets the hub and in the same spot on the inside. Rotate it, is it smooth and free ? or is it notchy, loose or grabby ? If so its bad. Many times a bad one will cause metallic munching noises, vibration that increases with speed, an ABS light.
I think the front diff is kind of a few and far between pattern failure in the front, the wheel bearing are common as the day is long and my 99 has always had a little howl from the front diff and transfer box, no problems with it beside 3 wheel bearing so far, got with 136k miles and now at 214k.
Always attributed the howl to the AWD which rules the roads once the snow starts flying, love good tires and mechanical AWD.

 

[jremington59]

What shape are your tires in? And are they all the same?

 

[Ptool2000]

The fronts are slightly more worn than the rears, but are the same. Really doesn't sound like a tire noise, but who knows. After I check the bearings I'll swap the tires. I'm hoping it's just bearings and not the diff. Been trying to determine if the noise is coming from one side or the other. Want to say driver side. I just bought the truck so who knows what to expect. It has just over 110K.