Moonroof Shattered!

[Tonester]

I was driving back to Sydney on the Monaro highway earlier today. I was about 10 kms north of Cooma travelling the speed limit (100 km) on cruise control when all of a sudden I hear an almighty smash. It was at the same time (I think, as it all happened so fast) as when a truck passed in the opposite direction. My instant reaction was that my Rhino roof box had broken by some flying debris or a rock.

I stopped to inspect and the box looked OK. Closer inspection revealed bits of glass on the back part of the roof. Stumped...it soon dawned on me that the moonroof had shattered. Sure enough it had.

The funny thing though was that the glass that had remained intact had been blown outward, not inwards as you would expect if the moonroof had been struck by a rock. I obviously did not slide open the shade cover for fear of glass dropping into the cabin.

I took it to Toyota in Fyshwick. They were great. They couldn't explain it and had seen nothing like it before. But they did help patch it up so I could continue on to Sydney.

So, my question is....has this sort of thing happened before? Are there any known issues with moon/sunroof on Toyota vehicles?? A quick google throws up a few similar cases, but these are a few years old.

[Hiro]

I was driving back to Sydney on the Monaro highway earlier today. I was about 10 kms north of Cooma travelling the speed limit (100 km) on cruise control when all of a sudden I hear an almighty smash. It was at the same time (I think, as it all happened so fast) as when a truck passed in the opposite direction. My instant reaction was that my Rhino roof box had broken by some flying debris or a rock.

I stopped to inspect and the box looked OK. Closer inspection revealed bits of glass on the back part of the roof. Stumped...it soon dawned on me that the moonroof had shattered. Sure enough it had.

The funny thing though was that the glass that had remained intact had been blown outward, not inwards as you would expect if the moonroof had been struck by a rock. I obviously did not slide open the shade cover for fear of glass dropping into the cabin.

I took it to Toyota in Fyshwick. They were great. They couldn't explain it and had seen nothing like it before. But they did help patch it up so I could continue on to Sydney.

So, my question is....has this sort of thing happened before? Are there any known issues with moon/sunroof on Toyota vehicles?? A quick google throws up a few similar cases, but these are a few years old.

Bit of a stab in the dark, but roof box is creating a negative pressure zone above the moonroof causing it to get sucked out?

[Tonester]

Hiro

Interesting theory. But I've driven the same route some 34,000 kms in the same car with the same box for the part 2 years. I think a pressure differential big enough to blow out the glass moonroof is unlikely. In fact, now that I think about it the box is shaped like an aerofoil (in side x-section). So, if anything, the pressure would be greater under the box and relatively less above the box. This would mean pressure is greater above the moonroof, not underneath it. If so, then that would cause the moonroof to be pushed in, not out.

I'm starting to think that IF it was a pressure thing it could have something to do with the truck passing the opposite direction. You get a massive gust of wind when travelling at speed and passing a large mass which is travelling at speed in the opposite direction. Could it be a sudden, but very quick, loss in pressure as the 2 vehicles pass each other?? Does anyone know what happens in this case??

Could the glass in the moonroof have microcracks which cause crack propagation under stress?? Happens in glass panes such as window glass. Yes, I know that glass in the moonroof would be tempered and laminated glass (or at the very least, laminated) which reduces the occurence of crack proagation, however, manufacturing variances could result in a faulty glass panel.

Whatever the reason, and assuming no rocks were involved, it should not have shattered. I was driving under normal conditions at 100 kph. This should not have happened!

Thoughts people??

[Turkey Galoot]

assuming no rocks were involved

Any new marks on the roof box that might point to a rock being involved?

Ken.

[Kesawi]

The critical factor is the pressure inside the car relative to outside of the car. While you are correct that the pressure will be greater on the underside of the box compared to the top of the box, it should still be less than the inside of the car (The car is also similar to a wing). I'm also assuming from your description that the moonroof visor was closed when the incident occurred. The window may have infact blown in and then sucked out after it shattered, and therefore you would be unable to tell the difference.

I have encountered the situation several times where I didn't close my hood properly and it was sucked open when I passed a B-double travelling in the opposite direction at 100kph each way. Fortunately the safety latch caught it.

[Hiro]

The critical factor is the pressure inside the car relative to outside of the car. While you are correct that the pressure will be greater on the underside of the box compared to the top of the box, it should still be less than the inside of the car (The car is also similar to a wing). I'm also assuming from your description that the moonroof visor was closed when the incident occurred. The window may have infact blown in and then sucked out after it shattered, and therefore you would be unable to tell the difference.

I have encountered the situation several times where I didn't close my hood properly and it was sucked open when I passed a B-double travelling in the opposite direction at 100kph each way. Fortunately the safety latch caught it.

Something that I thought of that would tie in with that, was one of the side windows open at all when the truck went past? High pressure pulse through the cabin, lower pressure zone between the roof box and the moonroof would make things worse.

[Tonester]

assuming no rocks were involved

Any new marks on the roof box that might point to a rock being involved?

Ken.

None that I could see

[Tonester]

The critical factor is the pressure inside the car relative to outside of the car. While you are correct that the pressure will be greater on the underside of the box compared to the top of the box, it should still be less than the inside of the car (The car is also similar to a wing). I'm also assuming from your description that the moonroof visor was closed when the incident occurred. The window may have infact blown in and then sucked out after it shattered, and therefore you would be unable to tell the difference.

I have encountered the situation several times where I didn't close my hood properly and it was sucked open when I passed a B-double travelling in the opposite direction at 100kph each way. Fortunately the safety latch caught it.

Something that I thought of that would tie in with that, was one of the side windows open at all when the truck went past? High pressure pulse through the cabin, lower pressure zone between the roof box and the moonroof would make things worse.

All windows were closed. The moonroof visor was, thankfully, closed as well. Otherwise I might have been showered with broken glass. I had the fan on (no a/c) to get some fresh air.

[El Grande]

maybe a rock had been throw up by the truck, looped in an arc (rather than direct, straightline impact) and then hit the moonroof? Good to hear you're ok...

[Tonester]

maybe a rock had been throw up by the truck, looped in an arc (rather than direct, straightline impact) and then hit the moonroof? Good to hear you're ok...

Yep, thought of that too. Maybe a rock may have deflected off the roof box somehow and hit the moon roof.

I suppose there really will be no way to tell what actually happened.

The question is whether it will be a warranty issue or an insurance issue.

[boleh]

"I can help you solve this puzzle"

[Tonester]

"I can help you solve this puzzle"

She can help me anytime!

Seriously, I think at this stage some close investigation is required.

Warranty was declined! Pretty vague reasons. In fact, no reason other than "it does not appear to be a manufacturing defect". Well I wonder how they can make this decision? What process did they use to arrive at this decision?? If they could demonstrate this to me then I wouldn't be so peeved off right now. This was based on photos (sent to Melbourne HQ) from the inside of the cabin. Photos from the outside could not reveal very much as the temporary plastic sheeting I had put on was not remoeved. Go figure. There was no evidence of rock/stone(s) in the space between the visor and glass. Roof box sits almost entirely over the galss.

My guess is that it was (in part, at least) a result from a pressure blow out, as the truck drove passed in the opposite direction. Whatever glass remained intact was blown outwards, not inwards as one would reasonably expect if a rock has hit it. If that was the case then the glass was not "fit for purpose".

I was hoping this wasn't going to happen as I now will need to pursue it more vigourously. Not happy Jan

Edited September 22, 2010 by Tonester

[idisc]

She can help me anytime!

Seriously, I think at this stage some close investigation is required.

Warranty was declined! Pretty vague reasons. In fact, no reason other than "it does not appear to be a manufacturing defect". Well I wonder how they can make this decision? What process did they use to arrive at this decision?? If they could demonstrate this to me then I wouldn't be so peeved off right now. This was based on photos (sent to Melbourne HQ) from the inside of the cabin. Photos from the outside could not reveal very much as the temporary plastic sheeting I had put on was not remoeved. Go figure. There was no evidence of rock/stone(s) in the space between the visor and glass. Roof box sits almost entirely over the galss.

My guess is that it was (in part, at least) a result from a pressure blow out, as the truck drove passed in the opposite direction. Whatever glass remained intact was blown outwards, not inwards as one would reasonably expect if a rock has hit it. If that was the case then the glass was not "fit for purpose".

I was hoping this wasn't going to happen as I now will need to pursue it more vigourously. Not happy Jan

Good luck with it Tonester. Definately the first time I've heard of something like this happening on any vehicle.

Personally I know that I never look at the moonroof, I either tilt it, or open it all the way; if the glass had a crack or chip in it, I would notice... Is it possible that it had been damaged someway before and you hadn't noticed?

[Tonester]

She can help me anytime!

Seriously, I think at this stage some close investigation is required.

Warranty was declined! Pretty vague reasons. In fact, no reason other than "it does not appear to be a manufacturing defect". Well I wonder how they can make this decision? What process did they use to arrive at this decision?? If they could demonstrate this to me then I wouldn't be so peeved off right now. This was based on photos (sent to Melbourne HQ) from the inside of the cabin. Photos from the outside could not reveal very much as the temporary plastic sheeting I had put on was not remoeved. Go figure. There was no evidence of rock/stone(s) in the space between the visor and glass. Roof box sits almost entirely over the galss.

My guess is that it was (in part, at least) a result from a pressure blow out, as the truck drove passed in the opposite direction. Whatever glass remained intact was blown outwards, not inwards as one would reasonably expect if a rock has hit it. If that was the case then the glass was not "fit for purpose".

I was hoping this wasn't going to happen as I now will need to pursue it more vigourously. Not happy Jan

Good luck with it Tonester. Definately the first time I've heard of something like this happening on any vehicle.

Personally I know that I never look at the moonroof, I either tilt it, or open it all the way; if the glass had a crack or chip in it, I would notice... Is it possible that it had been damaged someway before and you hadn't noticed?

Definitely no chips or cracks in it. Sheet glass does have micro-cracks. Can't see them but exist over the surface of the glass.Usually not a problem until put under stress. These micro-cracks cause crack propagation and lead to failure in the glass. Tempered glass, however, reduces the incidence of microcracks and therefore fails is greatly reduced when the glass is places under a tensile and/or impact load. A manufacturing fault perhaps in this case??

I did some googling last night and there have been some (not many) instances of spontaneous shattering of moon roofs. Not in the Kluger but in other models/makes.

There was also a known problem a while back where the rear window of Toyota utes did the same thing...spontaneoulsy crack. Unsure of the reasons though.

I understand that given sufficient loading, glass including tempered/toughened glass will fail. But in this case the moon roof glass was placed under normal operating conditions and should not have failed. So, it's not fit for purpose. If a rock or stone had hit it then I would accept that it was an accident and go via an insurance claim.

Wait and see I suppose.