Drop hitch problem

[ldsparamedic]

My wife and I bought our 1 ton dually about 2 years ago. It had a ball hitch installed in the bed for a gooseneck. We were planning on having a removable ball installed so we could flip it over and use the bed of the truck without having the ball sticking up.
A couple of weeks ago I was inspecting the driver's side wheel well and noticed a pull type handle, similar to one used on a 5th wheel hitch. I crawled underneath and lo and behold, we have a "flippable ball" Here is the problem.

The dealer did not know about it, the truck is a 2004 model so it is safe to say it has been rusting in place for the past 5 years. I have tried the yellow can of PB buster to loosen it, but it will not budge. I was thinking about putting a pipe wrench on it, but don't want to ruin anything. We have a sprayed in liner (line x) so I can't use heat.

Can I hammer this thing down through the bed or does it have to come up? Does anyone have any suggestions on how to get this very stuck ball freed?

[randallhilton]

My approach would be from beneath, if possible, even if it meant pulling the wheels (after properly supporting the truck with jack stands).

Are you saying that you can't get the handle to budge? Look underneath and see if you can figure out whether the handle rotates, if so, which way would it go? Or, does it pull or push laterally?

Once you figure that out, pull/push while tapping with a 2# hammer to see if it will loosen up.

Also. . . the sprayed on bed liner might be gluing the thing together, keeping it from flipping. Can you cut around the outline of it with a utility knife?

[Prairie]

What he ^^^ said. Plus, get underneith it and clean the mechanism good with a wire brush and spray your WD-Liquid-PB whatever on it and be liberal with it. Maybe even spray it again tomorrow. It'll come. And don't forget to check that the spray liner didn't glue anything together.

[ldsparamedic]

My aplologies, the handle and locking mechanism are free and work, the hitch ball itself is the problem. I did trim around the ball and removed the sprayed liner stuff, to no avail. I can't get a solid swing as the axle is in the way from beneath.