Cracking windshield...yet again.

[gran racing]

It seems like every year I have to replace my front windshield. Is there anything I can do (reasonably) to prevent this from happening again in several months?

------------------
Dave Gran
NER ITB #13
'87 Honda Prelude si

[Jake]

If the window is installed with a different adhesive it will allow it to "give" just slightly. I believe it's a type of butyl. Normally when the glass is installed it done in a way that it is really structural - but since we have cages, we don't need the glass to help prevent roof crush. However, I'm not sure who you can get to install a window like that.

[lateapex911]

not sure why you are having issues. Rock hits? cracking?

Mine is installed with soft gaskets, and clipped in place. I figured it would be easier to change out when I was at the track and needed a quick easy change.

It was a great way to ensure nothing would happen!

------------------
Jake Gulick
CarriageHouse Motorsports
ITA 57 RX-7
New England Region
[email protected]

[gran racing]

I'm not sure why I'm having issues with it either. This time it has developed a crack on both sides of the glass. Maybe hitting the rumble strips too much?

------------------
Dave Gran
NER ITB #13
'87 Honda Prelude si

[Dick Elliott]

The only thing holding my windshield on to/into my GT -3 car is the required safty clips. The lip that holds the rubber molding to the car has been cut away and the rubber molding thats left, stays with the windshield. Been that way for over 20 years with no problems. Windshield can be changed in a couple minuite. Still woun't stop big rocks though.

[Blix]

Dave...if you don't think the crack is from a rock or some sort of damage (crash, bump, wild hammer swings in the garage), then it could be from your chassis flexing. Find out if people with the same car and cage as you have this problem. I would check all the welds on your cage and spot welds on the car to make sure you haven't broken anything. Having a window crack due to chassis twisting would be a sign of a bad thing...If a bunch of people with the car and cage have the problem, you might want to add a bar or bars somewhere to couter act the problem, if not, you might have a problem specific to your car.

It could also be from vibration, in which case you might be able to fix it by changing how you mount it, but rule out the most serious possible cause first.

Just my .02

[Greg Amy]

Sometimes a cage makes the problem worse.

Back in "the old days" we used to have a problem with the firewalls on the Dodge Shelby turbos cracking, right around the radius where it meets the exhaust tunnel. Found out the problem was that when we turned them into race cars and installed rollcages (which stiffened the rest of the car but didn't allow tubes to the firewall or to the front suspension) all of the stresses of the twisting of the chassis were being focused right on the firewall. The only "real" solution we found was to weld in a double firewall, but that soon got discovered when some bright fellow drilled inspection holes...

So, you resigned yourself to having to reweld in a new firewall every couple of years (if you kept it that long). I hear the Neons - which are derivatives of those old cars - have the same problem.

<shrug>

[zooracer]

I also had my windshield crack after just two schools and one race. It was a new (used) windshield also. The crack started at the very bottom, right at the edge.
I had thought it was just chassis flex from the rigors of racing...
I might look into mounting it with some clips instead of glueing it. Just seems like it would move around without any glue, vibrate and such...
matt

[racer-025]

These windshield corner cracks are usually due to the vehicle having too much stress at these corners. This is mainly due to an overly used chassis (usually high mileage) causing the body to flex so much that the a-pillers exsert too much pressure at these points during racing and/or high abuse causing the windshield to crack. Stiffing up the chassis will help, but its tough to fix...

[joeg]

Urethane "Glue-ins" make the windshield a strutural member and is used to keep the glass in the car when airbags go off.

Butyl tape or rubber gaskets do not have that kind of issue to deal with, so are both easy to remove and crack less.

If you use a glass installer, he is likely to glue it in unless he is convinced your race car is not to be used on the street, in which cas he may resort to Butyl. Legal consequences flow from using Butyl instead of Urethane if specified by the OEM (with an air bag car).

[Knestis]

I don't know what kind of car we are talking about but modern vehicles derive a lot of stiffness from the windows being glued in, in their stock form.

K

[Fastfred92]

Another possible reason is improper prior collision repair is putting additional stress on the glass...

another .02 worth

------------------
Fred Alphin
#92 Hankook Tire SSB VW GTI VR6
BMW 325i ITS ( 2006 ? )

[JIgou]

Jake (or anyone else set up this way):

Can you give a few more details on your soft gasket/clipped windshield installation?

I'm pretty much living on borrowed time with my windshield (small crack on passenger side), and would like to go this route for replacement.

Jarrod

[Ron Earp]

Yes, would like details too. Just got a new windsheild and they are $450 each for a JH - when you can get one. I'd like to not have to replace it soon. Thanks,
Ron

------------------
Ron Earp
NC Region
Ford Lightning Tow Beast
RF GT40 Replica
Jensen-Healey ITS
1/2 a 260Z ITS - Zero

[Knestis]

On the old GT and TransAm cars, we used to fill the window frame with silicone sealant, float the windshield in the goo with its edges wrapped in Saran film, let it cure, then lift it out. We could then put it back in with the clips, so that it had a custom-fitted seal to snuggle into.

K

[7racing]

Originally posted by gran racing:
It seems like every year I have to replace my front windshield. Is there anything I can do (reasonably) to prevent this from happening again in several months?



Possibly you have a bent "A-Pillar" that is putting some extra stress on the windshield?

Jeremy

[gran racing]

O.k. This post has been a bit depressing.



------------------
Dave Gran
NER ITB #13
'87 Honda Prelude si