Ok, I give up– what’s an A frame window anyway?  You’re right, you may have never heard this, it refers to the 3 section window frame just after the windshield.  One pane slides while the other 2 are fixed.  The “slider” window moves through a felt lined groove.  Now that I’ve probably bored you “seasoned” GMC owners,let’s get down to business.  Just like everything else on our classic coach, the black frame, sealers & felts have all been damaged by the ravages of the years.  The color is spotty, the sealants used to keep this window from leaking are long gone.  The felt runners for the slider glass has become petrified, some actually deteriorated down to the wire liner.  So where do you start, how do you make this assembly look as new as the fancy new base/clear paint job? How do you reseal the glass and frame and how do we renew the slider window felts? That’s exactly what we will do here.