I bought my 2001 dodge ram 4x4 new, after 20k miles it started making a moaning, vibration noise when it was cold and in reverse. the Dodge house changed the valve body but it still made the noise. The Dodge house said it was normal and was some checkball Vibrating. So I continue to drive it and do filter changes.This last filter change at 80k I find a 3/4 inch piece of snap-ring in the transmission pan.I call the dealer and they dont have a clue. I talked to a local Transmission shop and they said it is part of the overdrive that the factory snap-ring was to thin. They said it was not a big problem and could keep working for years or I could have a upgraded snap-ring installed for $400. I not ready to get rid of the truck yet, and I am not kean on metal in my transmission so I guess ill get it fixed. [&o]

 

mine also makes a moaning sound in reverse when cold. i think it is common(normal).
if you're going to keep the truck, i'd agree it might be $400 well spent to replace the broken part and have it checked out. the other part of that snap ring is in there somewhere, just waiting to break again and come out and go who knows where and tear up who knows what... might save you $2000 somewhere in the future.