Clutch bushing woes

I have a 90 F350 diesel with a manual trans. The bushing under the dash that also acts as a retainer for the rod from the Clutch master cylinder keeps popping off and sometimes it actually breaks. I'm not the original owner of this truck, but when this happened the first time, I replaced the bushing and noticed that the rod that it slides over, looked like someone had filed it down. I replaced the rod and a new bushing. It lasted about 6 months and popped off again. Lately, I don't even get a week out of this bushing. Something is not aligned right, that's all that I can think of. Maybe someone out there has a diagram of what the clutch pedal linkage under the dash looks like and see if there are other bushings that may have worn out?