68 bus cab doors

[skin daddio]

what is with the 68 cab doors? they grow hairline cracks under the window scraper molding, and work out toward the door's mirror. i've seen this again and again in junkyards. when i pick a 68 i check and find the cab door, especially passenger side is cracked. i'm having a time with the passenger side on mine. about four years ago i had a gusset welded on the inside, reinstalled the window and trim. now its cracking and rusting again.
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?

[TexasAirCooler]

I'm diging through unanswered post and seen this one.
I had noticed this problem also. My '68 has them but the '70 doesn't. I can't figure out what they changed in the door to stop this.

[Amskeptic]

My bus has this crack also, on the inside near the vent window.
I think the doors are involved with chassis integrity, particularly when rust begins to take away some of the rigidity of the body shell, from the hinges on the a-pillar to the striker plate on the b-pillar. If you jack your bus up at the front port and the doors close hard, you will have evidence of this. It looks to be a tension crack (as in "to pull").
Colin?

[skin daddio]

yikes, never saw cracks on the inside, the ones i see are always on the 68ers and on the outside.