Our 7720 Titan II will engage the seperator on its own. Sometimes sitting at idle and sometimes at WOT when traveling down the road to another field. Most of the time when traveling across the field or going down the road it will just start grabbing and squalling instead of full out engaging. Also when disengaging the seperator you can hear the belt slapping/thumping against the belt traps. So far I've tried tightening the traps up tighter (around 1/8"), putting the traps out as far as they will go, adjusting them up to the specs in the operators manual (1/4"), installing a new seperator belt, adjusting the seperator belt tension via the turnbuckle and watching the sheetmetal gauge. I cannot figure this thing out. What else is there? This just started out of the blue when cutting wheat this year and has steadily gotten worse. Any ideas?