I have an 06 2500 5.7 Hemi 6 speed manual 2/4. I noticed mid week last week when I was slowing down that I started to hear a zing sound coming from underneath my truck. I only heard it a couple of time in a 3 day span. This past Sat I was driving and started to hear it again a little more often. It is a zing sound. Kinda sounds like that high pitch vibration a skil saw gets when finishing a cut. I thought it was only happening when I would take the truck out of gear to come to a stop but I left it in gear a few times when coming to a red light to see if it happend and it did. It only happens at low speeds though. I have no idea what it may be. I don't think it is the throwout bearing but I can't be 100%. Any ideas?

 

If it happens when you are pushing the clutch in then I'd be inclined to think it was a throw out bearing for sure... but if it happens without you even touching the clutch then it's time to do some more investigating...

If you could get a video of the sound it might help us, but a "zing" is a first for me... I've heard everything from "whomp whomp whomp" to "blat blat blat" but never a "zing"

 

Could be a brake as well. I would check all of the pads.