I have a 97 Expy 4x4 with just over 100,000 miles. Recently I started hearing a noise. It sounds a lot like I have a nail in a tire but the tires are fine. It sounds once every tire rotation and only can hear it at idle speed. If I barely step on the brakes, the sound goes away. I pulled the wheels the other day and turned axle by hand but no noise. Does anyone know what might be causing this noise?

 

I'm willing to bet that it is rust scale inside the parking brake drum. You cannot see this unless you pull off the rear rotors.

 

But the sound is coming from the front end, not the rear.

 

You didn't say it was the front in your first post.

Either way there is a high spot on the rotor that is hitting for each revolution of the tire. If the noise was every other revolution of the tire then it would be a wheel bearing since those rotate at half the speed of the tire.

If you want to confirm that it is not a tire, rotate the fronts to the back one at a time and see if the noise moves with them.

 

Sorry for not saying the front. That might be it but like I said, I did turn the wheels by hand and got nothing. When I turned them, I felt no spots that the pads were hitting the rotors. They turned freely. I sprayed everything down hoping maybe something was sticky but nothing changed.

 

The difference might be due to the fact that there is no weight on the wheel when you have it up in the air turning it. And you're sure there's nothing stuck in the tread like a stone or something like that?

 

Positive it is not the tires. Thats why the noise stops when I even just barely push on the brakes. I thought the same that taking the weight off might effected something. I may just have to deal with it. At least until I decide to change out the front pads. Then I might dig around a little bit more to see what it could be. I was just hoping something like this has happened to someone else that could tell me what it is exactly. Thats for the input ALLORO.

 

MAYBE a rotor is warped. Is there a pulsation when applying the brakes?

 

Dont think it is a rotor either. It brakes smooth as silk at all speeds. I just can figure out the "clunk" sound at every rotation and only at slow speeds. Like I say it sounds a lot like a sound of a nail or screw in a tire but that has been ruled out. Sound goes away with just the slightest pressure to the brake pedal. I might just have to live with it for now.

 

I suppose it could be a bad CV joint up there. Have you rotated the tire back and forth to check for excessive play?

 

No I have not. How do you check for that exactly? Do you jack it up then move the tire back and forth quick to see if there is any looseness (free play) before it moves back the other way?

 

That is correct. What you're looking to see is if the shafts on each side of the CV joint move together or if one moves before the other. They should move together with very little to no play.