Wolf, mine were and for the most part do the same thing. You crank them down and try and lift the trailer just enough to stabilize it, not pick it up as I dont think you could with these, however when you just let off on the handle it will spin the handle until there is no pressure left on the jack, and will spin fast. The more weight the faster it spins and it might even go an extra turn and than be actually off the ground. I have 4x6 blocks under the jacks so they are not turned that far down.
If I am not mistaken these hold themselves up via friction against the nut on the inside, you dont think that they could already be worn?
2013 F150 FX4 Crew Cab Lux Package
2013 Forest River XLR 27HFS