Digging this one out of the archives to keep them complete.
Had the lower pin on the driver's door bust on me this week. Took the door off and got the hinge out, but the pin was stuck in each of the pieces. Was able to drive it out of the door side of the hinge, but the body side was really stuck.
Joel came over and gave me a hand, eventually we ended up heating it til the hinge was bright red and driving a 1/4" roll pin driver through the pin. We drove the upper hinge pin out as a model and hit Lowe's for some replacement pins. The 1/4" pins were smaller, the 5/16" pins were bigger. The lower had been stretched out so we finished reaming that out to 5/16" and put the old pin back in the top.
Bottom lines :
'84s use roll pins like all the others, but have rubber plugs in them to make them look funny if you're not paying attention
1/4"x2" pins are longer than 5/16" x 2" pins (go figure)
The pin is probably a 7mm pin rather than a 5/16" or 1/4", which is probably why people have problems with the 1/4" pins falling out.
Anyway hope this pain helps someone else as those pins are a pain in the rear.
Bill