I have had this very strange noise for about 6 months now and was just able to find out the area it is coming from.

When I put the truck in park and shut it off I would hear a grind/squeak as the truck rolled forward or back with the amount of play found in an automatic transmission when in park. I have been able to pinpoint the noise coming from the rear right tire area. If I go to that tire while in park, engine off, and roll the truck forward and back slowly I can recreate the sound. I have no idea what is causing it.

I removed the tire and can not recreate it with the tire removed. I will have to try again but I wonder if when the truck is jacked up it relieves the pressure from what ever is causing the noise.

I just removed my caliper bracket and pins and regreased them. Still no luck.

Any ideas?

 

I have the exact same problem except mine is in the left front wheel. I have a 2001 2WD.

 

I still have no idea what is causing it. I have now jacked up the rightrear without removing the tire and then would rotate the tire in the air and the noise is gone. It is only when it is on the ground. Is there somethingI can grease in the rear? I am at a loss.....