Should a windshield crack from the cold!? 2 questions

I have a 2004 Subaru Forrester. I thought it was a a car built for inclement weather and bad driving conditions. I was driving in the suburbs on a perfectly good road in cold weather - about 20 degrees - and I had the defogger on. I heard a “thwack” which I thought was something dropping on the roof of the car, but there were no trees or buildings nearby. Some minutes later, I noticed a long crack in the windshield in the lights of an oncoming car.

It’s about 2.5 feet long, starts from the bottom of the glass, where it connects to the body of the car, at about midpoint on the driver’s side, and travels to about the same point on the passenger side, in an arc about 3-4 inches high. It looks like it traces the arc of the spill of air from the defogger onto the windshield. Is it possible the difference in temperature inside and outside the car could cause the glass to crack?



My second question is - my insurance company is steering me to have the repair done by Safelite autoglass. They will automatically install a manufacturer’s equivalent glass, but I’ve asked for Subaru glass as I think using a non-Subaru part would reduce the value of the car. But I’ve also heard not great reports about Safelite operations. Has anyone used their services? Any thoughts? Should I insist on getting the repair done by a dealer-recommended shop instead of the Safelite?



Thanks in advance!

Using this site’s Search function on “windshield crack cold” gives the first answer: no, but yes. That is, it “should” not crack, but it COULD crack.

Second answer: I’ve used Safelight more than once (Sigh!), and they did OK by me.

It is probable there was a small chip or defect that contributed to the problem, or even something just happened to hit it you did not notice, I would not blame Subaru on that one.

Glass is funny. It’s very strong in some respects, and very weak in others.

Your windshield cracked, so deal with it. Have the windshield replaced by the company your insurance company recommends. There is ZERO difference between a Safelite windshield and a Subaru windshield, other than the name.

Subaru does not make windshields. Subaru buys windshields from suppliers, of which there are few.

You hear an impact. Glass doesn’t ‘twack’ when it breaks from thermal stress. It would have been a ‘tink’.

Also, there is nothing wrong with Safelite glass. It will not reduce the value of the car. All Subaru glass will get you is a lighter wallet to pay for dealer mark-up, then added delivery to the shop. As stated, they don’t make glass. They also do not replace it. They outsource that work. Probably to the Safelite people.

Nothing wrong with Safelite. People don’t look to check to see what brand glass is there. As long as it is in one piece and not scratched and cracked, they don’t worry. I’ll bet you did not look to see what brand glass was on your car when you bought it.

Windshields can crack for any reason. If you do or don’t use Scotch-gard, it can cause a crack. Nobody cares about non-Subaru glass except for Subaru. Subaru glass does not exist no matter what a label says. If you save some money, you will be better off.

It could be a simple stress fracture. Car bodies are not 100% rigid and every car body suffers some body flex while driving. Maybe you just happened to get one of those with a tight fitting windshield and age/miles caused the glass to give up.

When I worked for Subaru I saw 4 or 5 Subarus that suffered stress fractured windshields and 2 of those were on near new cars; 200 miles or less.

Any aftermarket glass is fine if it has the DOT stamp on it. Keep in mind that Subaru does not even manufacture their own glass. They have it made for them and it’s quite likely made by the same company that provides glass to the neighborhood glass shop.
The only difference is the stencil used.

Thanks to you all for your responses. This is very reassuring. The Safelite info is good to know, as it is the most convenient place to take the car, and less expensive. I googled 'em and found some pretty negative statements, so I figured there was only one place to turn - Click and Clack and their ardent fans. Many thanks for the helpful advice! One new windshield coming up! Phew.

The temperature can contribute to a windshield crack. To prevent this from happening again in the future, it would be best if you’d apply window tinting on your car. While others find this capricious, it is 100% helpful to one’s car.

Safelite I had lots of leaking problems as they used their own spec glass in my 1988 VW Jetta GLI 16v. Apparently I had a rarer VW Jetta actually built in West Germany due to the high performance model. The majority were built in Mexico and the steel stamping presses including windshield frame was different enough to make slight dimension change.

Safelite came through and ordered German built dealer glass that properly fix my windshield and never another problem. They did this at great loss since they already put in two of their own windshields and then had to pay VW prices for glass the third time.

I was impressed by the shop although aggravated at the situation.,

They are designed to stand up to extreme temperatures…But that doesn’t mean they will all the time. It DOES happen…not too often…

An idiot I use to work with…decided one day to put boiling hot water on his frosted windshield to quickly remove the frost/ice…it cracked in about 1,000,000 places…New windshield.

It’s possible the windshield was manufactured with a flaw, which contributed to the problem. Or, since it was at night, a piece of gravel or other object may have hit the windshield and started the crack. I remember having a chip in the windshield of my 92’ Caprice. On a cold winter day I turned on the defroster on high and watched a crack spread in both directions until it almost reached each side. It was kind of fascinating how much symmetry there was in the crack—it stopped at the same distance from both edges of the windshield, and both edges had a little curl. I suppose Safelite is OK as long as they give you a decent warranty on their work. Other than that I’ve never had dealings with them and can’t say if they do a good job or not.

I am glad that folks report having good experience with Safelite, but…

I have never used them because a buddy who lives in a different city managed a Safelite shop for many years. When I asked him what kind of windshield to have installed in my Volvo wagon, he only advised “NOT a Safelite”. He said that it was not as thick or as strong as my original glass.

With regard to the value of a the vehicle, I agree that no one looks at the glass when they buy a car, other than to notice if it is cracked or pitted.

Explain how applying tint will insulate the glass from temperature extremes. This makes no sense. The only thing window tint does is reduce the amount of sunlight and UV rays from getting into the car, not affecting the glass itself. And, it can affect night time vision. And, most important, it is illegal to use on the windshield except for a narrow strip along the top for a sunshade.