My only occurrence was a 50 mph to 0 mph panic stop. I had heard of it before, so it wasn't a huge event...but a bit of a surprise. After getting a direclink brake controller (much smoother ramp up of apply), bleeding my brakes, and disassembling my Hensley (Used) and repacking and adjusting the bearings, I have had no further incident of the "bump". I am of the opinion that, although the Hensley utilizes wheel bearings in its pivots, they should be adjusted quite a bit tighter than one would with wheel bearings.
They have a large amount of levered pressure on them from the sides of the bearings and they don't spin with any appreciable speed like a wheel bearing, so virtually no free play is desirable, IMO.
"If the women don't find you handsome, they should at least find you handy." - Red Green