Need a simplex se top plate

I have not dealt with one of those in years but I can not imagine how one could be worn to allow the adjustment bolt to rotate. They have a cotter pin in the bottom to hold them in, hopefully bent just enough to keep it from coming out. Is the cotter pln missing allowing the excentric bolt to ride up in the plate?

 

That was a common problem on those 5th wheels. Rebuild parts are still available, if the plate is in good shape other than the adjustment pin hole, they used to make the adjustment pins with oversized hex heads to correct that issue. Might be a cheaper option if they still make them. It's been a while, but I have installed many oversized pins on those. If an oversize pin is loose, the plate is junk. If it's too tight, you have to do a little reshaping of the hole to make it fit snug. Most of the time, they are a little tight and you just hammer them in and out a few times. If you cannot lightly hammer it in, you'll need to do some grinding.