beemerphile1 wrote:
The relationship between the ball height and the receiver height is meaningless.
When backing up to hitch you obviously need the coupler to be higher than the ball so the ball can go underneath.
Not true. If they are not the same height when both are level before hitching you will end up with one or the other (possibly both) going down the road unlevel. ie; nose high or nose down
Of course you have to raise the trailer tongue above horizontal to make the connection. Common sense.
Setting the proper "at rest" ball height is necessary to have a level trailer and tow vehicle while towing.