2010 Fusion AWD Shaking/Banging under acceleration

Hi, I have a 2010 Fusion that has been periodically banging/shaking when accelerating. It starts around 40ish mph and doesn't quit until I drop below about 15 mph. It will often happen two or three times in a row and then it'll go for a week or more without doing it. Once it quits, everything is good. It runs smooth as glass at 80. The front axles have been replaced, front wheel bearings, one outer tie rod, both inner tie rods, brakes have been inspected, I checked the drive shaft to the rear and the rear axles. Nothing seems to be loose or out of balance. The point of origin seems to be front and center and the shaking/vibration is up and down (not side to side). The first few times it happened, I thought it was bumps in the road. Is this a known issue?