At about 8,000 miles my truck started doing this same single knock when turning the steering wheel either left or right at slower speeds. Today took it to the dealership for them to diagnose and repair this issue. Just got my truck back and the issue was a number of loose fasteners. The following six (6) separate fastener types needed to be re-torqued to spec.
1. Lower Control Arm Nuts: 100 N-m
2. Shock Absorber Lower Bolt: 168 N-m
3. Stabilizer Bar Bolts: 45 N-m
4. Stabilizer Bar Link Lower Nut: 119 N-m
5. Stabilizer Bar Link Upper Nut (18mm): 93 N-m
6. Stabilizer Bar Link Upper Nut (19mm): 100 N-m
Sure seems like a lot of fasteners - too many, in fact. Doesn't seem normal?!? I rarely hear of this needing to be done on a new vehicle. Or maybe it does need doing, but nobody ever does it or knows because it is caught when the vehicle's in for tires, alignment, or suspension work...