Shattered

Ever have a window on your car explode for no aparrant reason? Happened to me the other night. While driving about 40 mph the back window self destructed. I've done some research and the only thing I've found is that it could be from a defect in the glass. Only problem is that the car is an 88 and I think it would have happened by now.

I'm in the process of replacing it, but wonder if the defogger / defroster system may be haywire causing the damage. It's the kind with wires crossing through the window. Does anyone know what the electrical specs should be? Or if not could someone test theirs? It's an 88 LE.

Thanks. -Andy.

I've never seen a window blow out like you described but have a buddy who's windshield suddenly crack all to hell. Without the coating on windshields, it would have "exploded". It was found that the windshield adhesive failed and when the car flexed it put too much stress diagonally.

I also understand that rescue personell sometimes use an automatic center punch to shatter side windows. I don't understand the physics but it has to do with the amount of force focussed in such a small point.

I highly doubt that the rear defroster caused the problem. There's fuses to protect against too much current

So I took your advice and got a new window. I haven't tested the electrical system yet, but it's been two days and the window hasn't fallen out or exploded.

It was a pretty easy fix. Caution: To even read my email or attempt my fix, you should wear safety glasses and gloves.

Cost: 75$; window 60$ from a junkyard. 12$ for some 3M window stickum.

Resources: 2; 2 helps

Schedule: 2 days once you get what you need.

Process:

1. Remove all X'tra window bits. I used hammers screwdrivers, my hands, a shop vac, and whatever else helped.

2. Scrape off old seal. I used a gasket remover and it scraped up the paint which necessitated some primer. I understand professionals can do better.

3. Suck up waste w/ shop vac and donate to nieghbors.

4. (optional) Prime exposed metal. Once dried, rub down w/ wet towel to remove paint dust.

5. Make sure window fits w/ the adjusting blocks in place.

5.1 If problems with 5, your junk dealer is at fault. Most junk dealers have a 30 day policy.

6. Apply 3M window bonding crap to window with about an 1/8th inch gap from the 3M crap to the edge of the window. The directions say the preferred process is to apply it to the blah, blah, blah, blah, but I'm sure I would have gotten better results if you do it how I say.

7. With help place the window exactly where you want it. Amazingly enough you could have done better. Move the window left or right so the gap is the same on both sides. If you have an up / down problem where the window is rubbing on metal abort.

8. Set the seal like a good mechanic sets heads. Slowly, methodically, systematically, and with increasing pressure. No more than a baseball bat or sledge hammer is necessary.

9. Admire your work.

-Andy. (*13)

P.S. The defroster has a connector that is easy to disconnect and reconnect

Glad to hear you're back in business.

Nice write-up too.

A couple of things.........17 years is a long time for a glass defect to show up. IMO it may be one of the following

1. Both my '88 Bonnevilles had IMO weak and flexible chassis, especially after a bit of rust set in. Numerous problems resulted, including doors that squirmed in their frames over bumps, cracked door trim pieces and stress cracks on both windshields.
Such flexing may break a rear window.

2. Also...............I have had 2 windows blow out (not on a Bonneville) due to idiot kids shooting at passing cars with pellet guns. Any budding snipers in your neighbourhood?

Tempered glass is used in all car windows except the windshield which is two pieces of glass laminated together using a plastic sheet. Tempering of the glass is a process in which the glass is heated then fractured and then heated to the melting point so that it fuses back together. It is designed to be very strong but when struck by a sharp object, such as a spring loaded center punch or small projectile like a pellet that puts a lot of pressure in a very small area it will break into small pieces. These pieces are designed to be smooth on the edges and thus not cause injury like pane glass would.

In the case mentioned in this thread, the glass may have broken due to twisting of the chassis or it could have been struck by a rock from a vehicle passing in the opposite direction both would have had similar results. Of course kids with pellet guns are also a possibility.

As far as the windshield is concerned, it withstands similar pressures and abuse without fracturing. When it does break it is held together by the plastic that laminates the two sheets of glass together. It is not, however, the same glass that is in the other windows. It is made by a totally different process that makes it crack or chip rather than shatter as the other glass does.

Now you know why rescuers use the side or back windows to get into a car following a collision. These windows offer easy access as they can be broken very easily. The windshield, on the other hand is a real challange and is only used as a last resort. Tool needed--Large fire ax! NOT a good choice.

(PS. 20 years EMS experience, Level 4 Vehicle Rescue)

i had a rear window do the same thing....turns out the chasis had a crack in it and was not welded proporly. Weld cracked, hit bump and cracked glass...end result...JUNKYARD!

This morning on my 2000 (93,000 miles) just had the rear window blow out. VERY loud noise (like popping a paper bag) - the windows is "intact" in the rear, but shattered. No holes in the glass and no dents close by in the body to indicate anything hitting it.
Closest I can figure was it was a passing car back-firing at the exact right frequency with the exact right temperature conditions yadayadayada.

I had this happen to me one time before in another kind of vehicle the heat caused the front window to pop and resulted in it landing on my hood at a stop light. It was due to the riseing heat in the car and the installer who put it in. Remember just because you call a professional doesn't mean he or she is. When getting a new window and haveing a "professional" put it in check refrences of the company and especially the technition installing your glass