Vibration/Humming

[janism1]

I was hoping someone could help me. I have a 2003 Trailblazer with about 91,000. Recently I started hearing a humming noise and it increasingly has gotten louder. The humming noise also changes with the speed of my car. I can also feel a vibration in the steering wheel and pedals. I had it checked to see if it could possibly be the wheel bearings but those are ok. What else could it possibly be? My tires? Thanks

[h2oskier5]

Does the humming go away when you turn side to side on a smooth road? also what speeds does it start at?

[janism1]

No, it sounds the same whether I'm driving straight or turning. I start to notice the humming/vibration at about 15 to 20 MPH and gets louder as I increase the speed.

[maxwedge]

Suspect a ft wheel bearing, Check for looseness in either front wheel hub.

[h2oskier5]

Ok so it's related to a rotating member.. Does it go away when you let off the gas? Drive shaft issues have that type of symptom..

Does it increase in relation to rpm of the motor (shifting up) or does it increase with the speed of the vehicle?

When you apply the brakes does it get worse..

I think we can narrow this down..

[janism1]

Ok so it's related to a rotating member.. Does it go away when you let off the gas? No Drive shaft issues have that type of symptom..

Does it increase in relation to rpm of the motor (shifting up) or does it increase with the speed of the vehicle? Increases with the speed of the vehicle

When you apply the brakes does it get worse.. No

I think we can narrow this down..

[kingjames1]

I changed the front wheel bearings which solved the mystery. Now wehen you come to a stop the brakes act like the ABS is kicking in even on dry pavement. The only thing I did with the brakes was to compress the pistons to get the calipers back on. How do you fix that?

What is the torque spec for the wheel axle nut?

Janis's dad

[maxwedge]

Not in the slip in the w/b box?, some aftermarket bearings have different than oe torque settings, 150# would be safe, but recheck the info. The abs sounds like a bad sensor, you may have to have it scanned with an abs function scanner, but check all the connections at the wheel hub first.

[kingjames1]

Originally Posted by maxwedge

150# would be safe, but recheck the info. .

That's the problem. I can't find the spec in the manual. It does show 77 lbs. for the bolts that secure it but not the axle nut. Thanks.