You may need a this wrench to pull the 1 1/8" or 1 1/2" nuts on the 3/4" or 1" shafts. This can be found most places where hitch balls are sold.
This is the non fuctional coupler lock in the raised position.
The recommended way to secure the Fleetwood Evolution 3 coupler to the ball is to use a snap pin as seen above. The typical coupler lock will not work (See the next photograph).
On my Fleetwood Evolution 3, the typical coupler lock as seen above does not work.
I purchased this lock from Lowes as it was the only one I could find that would fit my coupler.