I have a 2001 Dodge Ram 1500 4x4. When I put it in reverse and am backing up it makes a squeak,squeak,squeak,squeak noise and I can hear that it is coming from the rear area when I lean out the window. It kind of sounds to me as if it is metal against rubber. Thats the best that I can describe the noise. Also it makes a ca-clunk noise when shifting into reverse. Not sure it that is normal.
Any ideas anyone?

Check the u joints in the rear driveshaft.Look for rust coming out of the caps.Unbolt the rear driveshaft to check them for binding also.

Ujoint

I would grease it first then try a new one