[mrraford]

I recently had the same experience. I found that if you "glue" the seats into place with a small amount of adhesive (I used a touch of silicon adhesive) then you can assemble the link readily. The movement of the plug and twisting the link before you shoot grease in breaks the glue and you are good to go. I was using those pesky lightweight nylon seats that made the problem worse before I thought to get the adhesive tube out.