Maybe just me, but i assume you are having trouble dropping it onto the ball.. correct?
I was having the same issues, it was also hard to release from the ball too. Both of my trailers have no adjusting mechanism and i havent found replacement kits like most. I first used WD-40 and deep creep thinking it would help, it didnt. I let a few months go by and gave another try with a spray liquid. This time i used a teflon base spray that i also use on my motorcycle chain. Worked excellent, it now drops on and releases as it should. The product is made by finish line, it is marketed toward bicycles but works great for motorcycle chains as well. It is their "wet" chain lube, black can, green top. Its now my go to spray if i need something teflon based... i used to use tri flow.