My 84 wagon has an annoying noise that seems to come from under the rear center of the car only when backing off the gas and coasting. (I would describe the noise as a drum roll, sort of a quick raping that slows as vehicles slows.) The noise will go away as soon as I push in the clutch at any speed. No noise at all on acceleration. I guess the fact that it goes away when clutch is in should be a good clue but it hasn't helped me so far. I suspect something in the drive train but can see nothing wrong that would do it from underneath the car. I have also tried removing and securing anything I could see that would possibly rattle inside the car. Any suggestions?