I have searched all forums and can't firgure out this problem. Here are the symptons:

1. Truck started making a real loud whining and grinding noise ONLY when making an abrupt hard right. It would continue for a minute while driving straight, then go away. Sounds just like a PS pump going out.

2. Eventually started making noise without turning (just the grinding and not the loud whining). Sounds like mud tire road noise.

3. Added PS fluid, it was a little low. The loud whining/grinding when making hard right went away but still does grinding noise when travelling straight or turning right.

4. The SLIGHTEST movement of steering wheel to the left, noise goes away completely.

5.Noise remains while engine is turned off and rolling down a hill.

6. Checked wheel bearings and there is no play and front wheels spin smooth and easy, no noise.

Eliminated wheel bearings and power steering pump since it does it with the engine turned off. Maybe steering box?

Any suggestions greatly appreciated.

 

I really don't know, but it seems to be the steering pump maintaining pressure in the system, probably some dirty inside of it or a clogged tube.

 

Ithought it might be the pump too but it makes the same noise even when the car is OFF and rolling down a hill.

 

It sounds like wheel bearings. Just because there is no play does not mean they are good. Sometimes it can be hard to tell. If you turn to one side and it grinds hums or growls more than likely a bearing because you're putting more force on that side. So if you go left then it's the right side and vice versa. Could be the rear wheel bearings on the axle also

 

Yes, in this case can be the wheel bearing, to test this you have to lift the car with it wheels off the ground and roll the wheels with your hands, if you notice some different noise can be it.

 

Lifted the car. Tires turn smooth without binding or grinding sound. Also no up and down play at all in hub. The sound stays same going straight as it does when turning right. Sound goes away when turning left.

 

I was wondering if you ever figured out the cause of the noise coming from your Tahoe/Suburban? I am having very similar symptoms and have no clue what is causing the noise.