Hi Newfly123, Welcome to the Forum! Could you post photos of your rod and the troublesome ferrules? The Johnson Profile fly rods were very nice rods with some of the nicest factory thread wraps ever. The forum background photo is a 3-piece Johnson 800 rod.
With metal ferrules the secret is keeping them really
clean. If the ferrules are dirty or corroded they won't work. Don't oil them or use WD40. Clean. The photos show a Phillipson made ferrule set, the same type that was used on your Johnson rod.
Here's how to clean the ferrules:
1) Use Q-tips and a solvent. I like mineral spirits or naptha. Isopropanol or denatured alcohol would work too. Don't use anything that could damage paint, like acetone or lacquer thinner. Don't use polishes, steel wool, sandpaper, files, or anything else abrasive.
2) This ferrule is actually quite dirty. Wet the Q-tip with solvent and swab the male ferrule to remove dirt and debris. A surprising amount of dirt will be removed on the first pass.
3) Do the same thing with the inside of the female ferrule.
4) Go back and use a clean Q-tip with fresh solvent and repeat the procedure. Do this again (and again) until the Q-tips no longer have dirt on them. This ferrule set took four passes to clean. The amount of dirt with each pass was less.
Here's how to assemble metal ferrules:
Note the shoulder on the male ferrule (marked with the blue arrow). Insert the male ferrule into the female ferrule by pushing it straight in. Don't twist. Do not use oil. The male should go all the way in if it is clean and undamaged.
Here's how to disassemble metal ferrules:
Hold the rod as shown and pull the two pieces apart without
twisting. Don't hold the rod by the guides. Definitely do not use pliers! Don't leave the rod assembled for long periods or separating the ferrules becomes very difficult.