I have a 2003 Ram 1500 4x4, Auto, 4.7L V8 about 115,000 mi. For the past few months I have been hearing some "gear noise" when traveling down the road. The type of gear noise you hear when running in a low gear is the only way I can describe it but very muted. I mostly noticed it with the windows rolled up and no radio playing. Lately it has become more pronounced and has gotten louder. I noticed that when I go around a right hand curve, the noise will stop only to return as soon as I straighten out. If I turn left, the noise gets a bit louder. Other than that the truck runs as expected, shifting smoothly. I can put it into and out of 4wd with no problem. There is no vibration. I was kind of thinking it may be a wheel bearing ready to go out. Any other ideas what might be happening?

 

Left side wheel bearing. When you turn right, you are unloading the right side, and putting more load on the left.

 

Thanks, I'll check it out