Clunk noise when turning a corner

The best approach is to have the steering and suspension systems inspected at a tire and alignment shop. There are a number of potential causes, but we need some details or clues to narrow them down. A binding upper strut mount can cause a thumping noise, but that usually does not occur when the van is moving. A badly-worn strut can clunk when the shaft shifts position. Lower ball joints and control arm bushings could be worn.