Banging on rear end when turning

[Dave mac]

When turning the back end of car rumbling and banging when going slow 

[Vauxhall Owners Club]

If the car is a 4WD then it could be the rear differential running on hard surface and they tend to make a noise with the transmission driveshaft winding up.....on Honda CRV this is a sign that the rear diff oil needs changing and it cures it (until the next change time is due)