Need info on B-Pillar Window Channel Installation in GTB | FerrariChat

Need info on B-Pillar Window Channel Installation in GTB

Discussion in '308/328' started by jhh925, Jun 2, 2025.

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  1. jhh925

    jhh925 Karting
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    Dec 2, 2015
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    Reno
    Full Name:
    Jens
    I'm in the process of re-installing the rear triangular windows in my 1987 GTB. When I test-fit the window assembly, there's this large gap between the top of the B-pillar window channel and the bottom of the drip rail trim.

    Here's a picture of the window assembly in position without any glue or rivets in yet:

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    Here's a picture of the same spot on my car at the time I was disassembling these windows:

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    I don't think I'm missing any parts, but was this gap really filled up like this with glue at the factory? Does anyone have any pictures of what this is like in their car?

    (Note that this gap is underneath the rubber door trim that will eventually get pressed onto the pinch weld.)
     
  2. Newman

    Newman F1 World Champ
    Consultant Owner Professional Ferrari Technician

    Dec 26, 2001
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    Newman
    There's a door seal cut to fit that the glass presses against around the window opening on the body and then yes sealant. With the doors closed those thin lip seals overlap a bit and do a pretty good job of keeping water out of the area. The sealant does the rest. And on the right side where the small vent is at the corner of the 1/4 window you're relying completely on that door seal to keep water out. I add sealant to that area before putting the window back in hoping it'll do something. That poor design is why the rear shelf on the right side rusts under the insulation on a GTB and eventually rotting a hole there.
     
  3. jhh925

    jhh925 Karting
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    Dec 2, 2015
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    Jens
    Gotcha, so if I'm reading this right, I'll need to put adequate sealant into the big gaps at the top & bottom of the aluminum window frame that gets riveted to the B-pillar.

    Yeah, this design is pretty crappy. I've been guessing that Ferrari planned (or hoped) that the drain holes in the bottom edge of the window gasket and in the body work right under the window gasket would be enough to let any water in that area drain out, so all the seals had to do was direct water to the drain holes. But based on, e.g., the BaT auctions on otherwise pristine 328s that all seem to show water stains on the parcel shelf, I'm thinking that the plan failed.
     
  4. Newman

    Newman F1 World Champ
    Consultant Owner Professional Ferrari Technician

    Dec 26, 2001
    14,414
    Canada
    Full Name:
    Newman
    The top front edge under the drip rail needs a lot to fill the gap and the vertical edge along the B pillar. The area behind the thin lip seal is left as is. The rear edge behind the louver I get creative so a garden hose aimed the wrong way wont send water into the cabin.
     

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