I have an F150 Supercab. All i need is about 1" max to be able to lower my tailgate with the trailer hooked up. Not sure I will invest in a longer hitch or not, they are not cheap, but it is frustrating to not be able to lower my tailgate until I unhook the trailer.
Not sure but I believe you are asking me where the screw is. The motor head on mine had a hex set screw in a collar at the bottom of the motor housing. Just loosened it a bit and the motor head can turn. Mine was on the truck when I loosened it. I don't know what sort of pressure is on the actual motor head, I doubt any but did not want to take a chance and loosen anything on the jack while it was supporting the trailer.
I'll likely end up doing something similar. With the motor head turned I can open the tailgate a bit more but still not all the way. I need just a little bit more room. Very frustrating. My jack stand is already mounted all the way to the rear of the plate it screws into so no room to drill new holes and move it back. I would need to weld a new plate onto the A frame of the trailer, or get a longer ball hitch for my truck. Oh well, it's on the list of mods for some day.