Quote:
Originally Posted by sc_rufctr
The 964 windshield is slightly bigger than a 911 so the seal is different.
But according to "aftermarket glass people" the window openings in the body are the same on all 911s (911, 964, 993).
However I'm not sure how true this is because I've never confirmed it for myself and people have had issues fitting
a 964 windshield and seal in a G Model 911. (It doesn't fit - too big)
What people have done with success is the installation of the 993 windshield and its glue in seals on a G Model 911.
This works well and I've seen it first hand. Very neat and tidy.
What I would like to try is a G Model 911 windshield using a 964 seal in a G Model 911.
It may be a bit loose but a bit of sealant (non hardening) in the right places may fix the problem.
And just for info...
A friend in the local Porsche club has been running an SC with just the glass, rubber seal and trim.
He uses no sealant at all on any on his fixed windows and has never had an issue but his car isn't daily driven and rarely if ever sees rain.
This subject has been talked about a lot here. Searching is a good idea but it can get confusing.
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I think the aftermarket glass people are mostly correct because the change in the window opening is slight. The tech bulletin below says the opening was changed in 1989 (likely in anticipation of the 964 intro) with a slightly larger pinch weld width
I think a lot of people that DIY their seals use no sealant because it's not something that is specifically required. But it does help. You can use the non-hardening material like 3M glazing compound. It fills the voids where the seal doesn't fully occupy the frame opening and it doesn't take much at all. We're talking about barely a couple of full squeezes of the caulk tube gun when you go around the entire perimeter of the seal.
The places where the sealant is most used is in the corners. Along the straight sections of the window frame, you can't really put much sealant in there because the gap between the bulk of the seal and the lip is very small. Anything you inject in there just oozes out when you press on the seal lip. I recommend masking around the edge of the seal lip after you have the windshield seated in place. Makes for faster cleanup of the sealant than progressively wiping it away with a cloth
My next windshield install on the '86 911 is going to be a 964 glass and 964 seal. I had intended on doing this with my racecar project but that never came together and is now in the process of being parted out. I was hoping to find a cheap/used 964 windshield locally for a test fit but never came across one. However there have been numerous mentions here over the years of using the 964 glass and seal w/success.
The 964 seal with 911 glass was often mentioned as not working because it was too loose of a fit. When I did my first windshield job on my former '87 in 2003, I tried the 964 seal with my existing 911 windshield (not Sigla original, Pilkington Sigla replacement) and the fit of the seal around the glass with it lying on the floor (on a blanket) was so loose that I knew right away there was no way the 964 seal + 911 windshield combo was going to work. So I used a typical 911 seal with the same Pilkington windshield and it's still performing fine with the new owner today in 2020 who has become a very close friend since 2014. He'd let me know if my install was going south
http://forums.pelicanparts.com/porsche-911-technical-forum/68438-windshield-gasket-replace-86-964-style.html#post667578
Regarding the 964 glass and 964 seal combo, it should work in a G body car. I've seen the finished product in person but I did not see the assembly/installation. A longtime good friend of mine had me garage his '78 SC targa at my house while he was moving from IL to Detroit and he wanted me to help sell the car. It had what I believed was a 964 windshield and 964 seal and it fit nicely. But Jay didn't install it himself. He bought the car from a local friend of ours who bought it from member Paul Sopp pbs911 here on the forum.
http://forums.pelicanparts.com/porsche-911-technical-forum/921267-trick-installing-964-front-rubber-windshield-seal-78-sc.html#post9572906
But it's not an absolute guarantee it will work. Some have tried the 964 glass and 964 seal and found that it was too big and they couldn't get the glass seated in the opening. Here's a thread with a few mentions of that
http://forums.pelicanparts.com/porsche-911-technical-forum/864351-964-windshield-rubber-seal-earlier-car.html
http://forums.pelicanparts.com/porsche-911-technical-forum/100874-964-windsheild-85-dont-do.html
In researching what pbs911 did, his second attempt at it appears it is a 993 windshield with the 964 seal!
http://forums.pelicanparts.com/porsche-911-technical-forum/64955-996-windshield-78sc-yes-you-can.html
http://forums.pelicanparts.com/porsche-911-technical-forum/71981-up-grade-wshield-opnions.html
I would never think to try a 993 windshield with 964 seal because the 993 windshield is a completely different sealing process with actual glue/urethane and multiple separate trim pieces. It's a nice setup and I know guys have done the complete 993 system in their G body cars with success.
So as you can see, when you go off the radar and use later 964 pieces, success varies. So does the quality of glass. Not all glass is the same, so they plays into it as well. Crazy.............