Here's what's on etrailer.com, "straight from the horse's mouth at Pullrite Hitch MFG".
https://www.etrailer.com/question-210690.html
Recommended Lifting Bracket And Crane For Removing 5th Wheel Hitch
Question:
Will it do damage to the king pin and pin box to let my Pullrite super glide hitch hang off the king pin when not attached to truck?
asked by: Stanley S
Expert Reply:
I reached out to PullRite and they said you can definitley use the trailer to remove the hitch from your truck, but you don't want to leave it hanging there. They suggest lowering onto saw horses or another sturdy surface. That is a lot of weight to leave on your pin box and king pin as well as the jaws of your hitch.
Here's another "generic hitch response from etrailer":
https://www.etrailer.com/question-77607.html
Can a 5th Wheel Trailer Hitch Hang from the Trailer Kingpin when Its too Heavy to Move Alone
Question:
I want to have my truck washed and the bed cleaned out but the 5th wheel hitch is to heavy for me alone so I was thinking to connect my truck to trailer secure my trailer and release pins on hitch and lift off my truck using landing gear and pulling truck away to car wash so my question is will that damage my hitch or trailer leaving it dangling there thank you
asked by: Candice
Expert Reply:
You do not want to do this. It can damage the hitch but more importantly if it were to fall it could badly injure someone. If you try to lift the whole hitch and base out together it is going to be difficult. All you have to do is unbolt or unpin (depending on the hitch model) the head from the base. Remove the head, then remove the base.
I'd be interested in what response you get from B&W.