Do I need a Thrust Washer?

There are 3 main scenarios where the Thrust Washer can be useful:

1. Ensures that there is no gap between the ball mount and coupler while tightening the adapter, especially in the connection of a step down coupler.
2. Provides extra stability when connecting to a flat coupler for a flush connection.
3. Slightly raises the connection point to prevent the bottoming-out of the hitch ball threads in the ball mount.