Found it, someone had made their own shcok absorber kit for this machine, not a factory deal, the mounting brackets had "flexed" enough to allow the chain to bottom out as when they put the shocks on the rubber blocks on bottom of feeder house drum roll adjustment arms were removed------------------ Took me 3 days plus a dealer service call to finally find this. Took the blocks of an old machine here that had burned a few years back, much quieter now.