While I love my OEM hitch and hitch mount, the constant clunking while trailering over every bump is pretty irritating. Apparently, my good friend was really annoyed while taking my boat to the launch ramp the other day.
He came up with a fix and insisted on implementing it.
On the bottom of the OEM hitch frame, he drilled a 1/4" hole and tapped a tapped it for a 5/16" screw.
We put in a 5/16" x 3/4" stainless screw which presses hard against the hitch mount. Now there is no wobble at all. It feels welded to the hitch frame. No one will ever be able to steal my hitch mount either, unless they have a proper allen wrench to loosen the hidden bolt.
Man, having good friends to help you out is great.

Better yet, when they want to fix your stuff without asking.
The whole operation took about 10 minutes with the proper tools.
Tools / Parts needed:
1) Drill with 1/4" drill bit (capable of drilling steel)
2) Tapping set with 5/16" tap
3) 5/16" x 3/4" stainless screw with lock washer