I just bought a new 2011 Ram 3500 Crew Cab larmie and had the dealer install some accessories one was the putco vent shade visors. I picked up the truck on friday night and drove it home 300 Miles. The next day i washed the truck and drove down to the local parts store to get some tire cleaner, out in the parking lot I was talking to a guy standing next to my truck all the sudden the rear drivers side door window shattered but was still in the door no hole. You can see where it started from was at the top of the window center. Has anybody ever hear of this happing. Glass defect ? Visor putting pressure on the glass with a weak point ? not sure what the hell happned If i was not standing there and heard it breaking i might of thought some thing hit it, but it was parked toward the building and there was no hole in the window. Then when I opened up the drivers door the glass fell out and damaged the paint on the outside of that door. So I called the dealer up and told them about it sent them pictures of the glass and where you could see where the crack started from, Not much help from the dealer yet. I'am not a glass guy so i would like any helpful info to go to the dealer with going to try to post a picture

 

The side windows of your car are tempered glass. Tempered glass is heat strengthened by taking the glass up to 1200F and then rapidly cooling it. This causes the exterior surface of the glass to compress while the interior of the glass is still quite warm and still in expansion mode. Ultimately, this translates into an exterior compression layer and an interior tension layer.

When the compression layer is breached, then all that tension is released (kind of like a spring) and POW! there goes the window.

Okay, then why did the side window break? It is certainly possible that it was impacted by a rock or bb or something similar, but I am guessing that it was spontaneous breakage based on the description.

As mentioned, tempered glass is tough on the face, but the edges are quite fragile.

One characteristic of tempered glass is that if it has edge damage it might not "release" immediately, preferring to wait around for awhile until it has a chnace to scare the @$#%@^@%#$@ out of someone sitting at a stoplight or else eating breakfast in their home. It makes for great conversation!

When glass is manufactured, it might have what are called "inclusions". Usually nickle sulfide or perhaps other trace elements, these inclusions can cause significant problems in tempered glass. While most glass with inclusions will break during the tempering process, some of them are just stubborn enoungh to make it past that process and into the actual finished product. These inclusions, like their edge damaged cousins, love to wait around awhile until everyone is quietly relaxing and then POW! no more glass in the window frame.

Typical breaking stress for annealed (regular) glass is around 6000psi. Typical windload breaking stress for tempered glass is around 24,000psi, thus the "four times stronger" comparison that many folks like to quote.
When impacted, tmepered glass is about double the strength of annealed glass. One typical lab test is to impact 1/4" lites with a 5gm missile. The tempered glass can withstand the impact up to about 60ft/sec while the annealed can withstand the missile to about 30ft/sec.

Ultimately, very few folks insure against glass breakage. Although spontaneous breakage does happen, I would suggest that proving it will be difficult and the last thing that any glass company wants to do is to deal with about 10,000,000 claims for spontaneous breakage - definitely a losing situation. And realistically, way more glass is broken for reasons other than spontaneous breakage...

Hopefully this made some sense!

 

Hey thanks for the info. It sounds like the dealer it going to take care of the window, Sounds like they have had a few of these windows doing the same thing.