My experience with putting weight
on the rear bumper.
Our first trailer was a 1982 Sunline, 15.5 feet in length. I mounted our plastic bumper box and placed an empty 41 pound generator
in the box for a 100 mile test run before our first trailer trip to Labrador. Within 20 miles the trailer swayed. I stopped the sway immediately by activating the trailer brakes
thru my brake controller's manual switch. In shorter order I again felt sway, nothing dramatic, but there none the less. I stopped the vehicle and moved the generator
to a location over the axle
, sway gone.
I learned weight belongs over the axle
. Since that day I've never had a sway experience.