Ferrari 365GTB/4 Windshield

January 17, 2021

The Windshield on this 365GTB/4 leaked pretty badly on my customer during the first rain storm the car saw. Many of these cars never see the rain, so people may never know how well sealed the windshield gasket fits until things get wet. Daytona windshields are notorious for leaking for a number of reasons. and I believe the factory resorted to sealing the edges of the glass to the body because even when they were new, they had problems.

This car was new to me, so I had no idea how this windshield was installed. The seal around the perimeter of the glass seemed to be intact, but from the video my customer sent me, water was getting inside the car pretty well. The only solution was to cut the sealant out and see what was going on.

I was pleased to see the integrity of the body was in good shape, so the leaks were not from rust or a deformed window frame, but there was very little sealant anywhere else than the edge of the frame. I could see any gaps between the glass and the rubber would have allowed water infiltration.

I got a new gasket and began the arduous task of fitting it to the glass. Anyone who has done this with a Vintage Ferrari knows this task can end badly. Anything from broken windshields to bent trim pieces can add up to a disaster, not to mention hours of repetitive strain on the hands getting these parts to fit and stretch into place.

The goal was to fit the gasket onto the glass, then get the chrome trim to fit on the gasket, then to get the whole unit to fit to the body of the car without breaking, bending, or killing me in frustration!

I had to start by making sure the glass would fit in the car with the new gasket. Reproduction gaskets can change in dimensions and cause all sorts of problems. Fitment of each piece affects everything else afterwards, so care had to be taken each step of the way.

Next was the installation of the chrome trim. That nearly killed me! I would get the piece 99% installed, but the last bit would be out of alignment forcing me to start all over. Squeezing the barb of the chrome trim into the rubber gasket would strain my hands into submission where after a couple attempts, I had to take a break for a few days so my hands could recover!

I finally got the trim piece onto the windshield gasket, but I was only half way there. I still needed to get the windshield installed in the car! This was done with a lot of lubrication and a rope to pull the seal around the lip of the windshield opening. This again was met with several attempts because movement of the glass, rubber, or trim a half a millimeter would sometimes not be apparent until the glass was installed and required removing the whole unit and starting again!

After several attempts I got the glass to fit to my satisfaction. Some of the rubber gasket will have to be trimmed with a razor blade, but gap was relatively even all the way around the opening.

The gap around the windshield surround will get a bead of silicone to seal the gasket. Looking at the before pictures, I think I have the same width gap as before.

I will be making sure I not only seal the outer lip of this windshield, but also the inner lip, as I believe this was the source of the water infiltration. Wish me luck!