OEM TESLA roof racks Crack Glass

[N54TT]

We have a winner! Except it wasn't "possibly" installation error, it *was* installation error. The arrows (^) on the protective vinyl *must* be lined up with the "^" mark etched into the glass. You really should have good light when doing this because the arrows are not very large and require a viewing angle that makes them stand out.

A lot of us have installed the rack easily with no issues. While I have an accurate torque wrench that I used, it's not really necessary if you have a reasonable level of mechanical competence. The reason I say this is the retainers are welded to the steel frame which is very strong and tightening the bolt draws the rubber pad on the crossbars onto the top surface of the metal roof frame very close to the retainer. So over-tightening can't deform anything enough to cause the glass to break. The way the glass could break through over-tightening is if the tightening draws the rubber pads all the way down to the glass. This can be checked visually. All of mine, tightened to spec, did not even touch the glass. Just check visually when tightening to ensure the rubber pad doesn't contact the glass. The torque spec is not very high because the bolt is designed in such a way that it's captive (rotationally) once installed and cannot rotate or back out when the rack is installed. In other words, the bolt does not rely on tension to keep it from backing out once the rack install is completed.

I said “possibly” to give him the benefit of doubt....camera angles can play tricks sometimes lol. I agree....Have seen posts showing the welded retainers and don’t see how the glass could break if installed properly. But then you have posts like @Marius A that report cracked glass with proper installs. Did you notice popping/cracking sounds that others reported when tightening down the nut? Could it be a QA issue ie with the welded retainers or installation of the glass?

 

[Marius A]

I said “possibly” to give him the benefit of doubt....camera angles can play tricks sometimes lol. I agree....Have seen posts showing the welded retainers and don’t see how the glass could break if installed properly. But then you have posts like @Marius A that report cracked glass with proper installs. Did you notice popping sounds that others reported when tightening down the nut? Could it be a QA issue ie with the welded retainers or installation of the glass?

I didn't get any popping sounds, but there were some cracking noises. I had read beforehand that we could expect this, and there wasn't much when I installed mine, maybe the final rotation. I wouldn't have noticed unless I had read about it beforehand. My manual said 5-6nm, so I went to 6nm and loosened to make it fit the lock.
Nothing happened during install, it was after a 300km drive with a ski box that I noticed the roof had cracked.
Luckily my insurance picked up most of the replacement cost.

Which makes me wonder what I'm going to do with my next TM3. I wanted to put bubblegum pink PPF on it, but it's a performance so roof rails is the only option to get stuff with me on vacation.

 

[StealthP3D]

I said “possibly” to give him the benefit of doubt....camera angles can play tricks sometimes lol. I agree....Have seen posts showing the welded retainers and don’t see how the glass could break if installed properly. But then you have posts like @Marius A that report cracked glass with proper installs. Did you notice popping/cracking sounds that others reported when tightening down the nut? Could it be a QA issue ie with the welded retainers or installation of the glass?

Yes, I did hear the normal slight pops when tightening. That is just the release of small stresses built up in the welds. All welds have thermal stresses in them due to uneven cooling, mostly at the beginning and ends of the weld. This is normal. The glass can't break unless the pads on the cross bars are contacting the glass. Visually check for glass contact during install.

My roof rack has been performing admirably. I even hauled a 10 foot long 6"x6" lashed to the rack for 90 miles with one burst of speed to over 100 and some of the roads I was on were pretty bad causing a lot of pitching forces. No issues. I've also hauled a roof-top box with it. It's well designed although some care should be taken during installation to visually ensure everything is being assembled correctly.

 

[CharleyBC]

We have a winner! Except it wasn't "possibly" installation error, it *was* installation error. The arrows (^) on the protective vinyl *must* be lined up with the "^" mark etched into the glass. You really should have good light when doing this because the arrows are not very large and require a viewing angle that makes them stand out.

A lot of us have installed the rack easily with no issues. While I have an accurate torque wrench that I used, it's not really necessary if you have a reasonable level of mechanical competence. The reason I say this is the retainers are welded to the steel frame which is very strong and tightening the bolt draws the rubber pad on the crossbars onto the top surface of the metal roof frame very close to the retainer. So over-tightening can't deform anything enough to cause the glass to break. The way the glass could break through over-tightening is if the tightening draws the rubber pads all the way down to the glass. This can be checked visually. All of mine, tightened to spec, did not even touch the glass. Just check visually when tightening to ensure the rubber pad doesn't contact the glass. The torque spec is not very high because the bolt is designed in such a way that it's captive (rotationally) once installed and cannot rotate or back out when the rack is installed. In other words, the bolt does not rely on tension to keep it from backing out once the rack install is completed.

Thanks! It sounds like you have this well analyzed. So I bet you can answer a question I've wondered about. When done correctly, do those hooks grab the underside of the glass, or do they grab some piece of metal below the glass? Is that what you meant by "the retainers are welded to the steel frame"? I've wondered if one of the reasons for breakage is not getting the hook down deep enough and catching glass rather than metal. But I haven't tried this myself yet, so what do I know?

 

[N54TT]

Thanks! It sounds like you have this well analyzed. So I bet you can answer a question I've wondered about. When done correctly, do those hooks grab the underside of the glass, or do they grab some piece of metal below the glass? Is that what you meant by "the retainers are welded to the steel frame"? I've wondered if one of the reasons for breakage is not getting the hook down deep enough and catching glass rather than metal. But I haven't tried this myself yet, so what do I know?

yes...here’s a pic of the welded retainers we are talking about.

 

[Marius A]

Thanks! It sounds like you have this well analyzed. So I bet you can answer a question I've wondered about. When done correctly, do those hooks grab the underside of the glass, or do they grab some piece of metal below the glass? Is that what you meant by "the retainers are welded to the steel frame"? I've wondered if one of the reasons for breakage is not getting the hook down deep enough and catching glass rather than metal. But I haven't tried this myself yet, so what do I know?

There's a retainer under the glass. For me the crack came from the top part being pushed down into the glass. Tesla said my PPF was the reason why that happened. Lucky for me that meant only the outer glass was cracked, while fastening it under the glass would crack the entire thing.

 

[CharleyBC]

yes...here’s a pic of the welded retainers we are talking about.
View attachment 481593 View attachment 481594

Extremely helpful for understanding what’s going on under there. Thank you!

 

[CharleyBC]

There's a retainer under the glass. For me the crack came from the top part being pushed down into the glass. Tesla said my PPF was the reason why that happened. Lucky for me that meant only the outer glass was cracked, while fastening it under the glass would crack the entire thing.

Why does PPF make a difference?

 

[Marius A]

Why does PPF make a difference?

I don't know, they refused to elaborate. Took it to two different service centers, but the second one just read the conclusion of the first one and repeated.

 

[StealthP3D]

Thanks! It sounds like you have this well analyzed. So I bet you can answer a question I've wondered about. When done correctly, do those hooks grab the underside of the glass, or do they grab some piece of metal below the glass? Is that what you meant by "the retainers are welded to the steel frame"? I've wondered if one of the reasons for breakage is not getting the hook down deep enough and catching glass rather than metal.

Exactly! If the glass breaks from finger tightening, it's because the hook was not in the retainer properly. The other way it can break is if the crossbar is not properly centered on the car (L to R) when tightening, one of the rubber pads can contact the glass during tightening.

This is not a difficult job or one requiring a high skill level but it does require a reasonable amount of care and observation to ensure everything is going together correctly. The problem happens when the person installing it doesn't understand what is happening and what they are trying to achieve. It's a well-engineered and robust design but the clearances are reasonably close to the glass such that an error in assembly could put pressure on the glass at which point it will break. Nothing should touch the glass!

 

[StealthP3D]

I don't know, they refused to elaborate. Took it to two different service centers, but the second one just read the conclusion of the first one and repeated.

I suspect they are blaming creep of the pads due to the adhesive layer of the PPF not having enough shear strength to handle the side loads of the mounting pads under cornering forces. Alternatively, it could be that the pads creep on the surface of the PPF (but I think this unlikely). It could also be that the PPF was not the problem at all but that one of the crossbars was not centered properly during torquing.

Without inspecting the result, it's hard to know which factor to blame.

 

[CharleyBC]

it does require a reasonable amount of care and observation to ensure everything is going together correctly

Reading this and similar threads, I've strongly gotten that impression. Yet until today, I didn't feel well enough informed to judge whether "everything is going together correctly". That is, one has to know what correct means. Thanks for explaining so well!

 

[Marius A]

I suspect they are blaming creep of the pads due to the adhesive layer of the PPF not having enough shear strength to handle the side loads of the mounting pads under cornering forces. Alternatively, it could be that the pads creep on the surface of the PPF (but I think this unlikely). It could also be that the PPF was not the problem at all but that one of the crossbars was not centered properly during torquing.

Without inspecting the result, it's hard to know which factor to blame.

I'm pretty anal about these things, I spent a long time mounting it, making sure the stickers were on right, re-applied the right front because I couldn't get the pad to align properly when thread over the j-bolt.
I asked if they could show me the correct way to fasten it, so it wouldn't happen again, and that's when they told me it was because of the PPF. Something they still haven't added a warning about from what I can see.

It is a robust design, but I don't think well-engineered is a good description when it's easy to make serious mistakes.

 

[StealthP3D]

It is a robust design, but I don't think well-engineered is a good description when it's easy to make serious mistakes.

I wouldn't say it's "easy" to make serious mistakes if you use a reasonable amount of self-awareness about what you are doing. It's actually pretty easy to install it correctly, just don't think it's like snapping two Lego blocks together - it does take more awareness than that.

Can you propose a mounting system that would be as sleek and robust but even easier to install? Without adding significant expense to the vast majority of cars that never have racks mounted? Please post the improved solution below and I'll forward it to Tesla for their consideration. Well, if I think it's an improvement.

The full glass roof definitely limits the available options. I like the chosen solution because Tesla didn't choose an expensive and overly engineered solution, just a simple and sleek one that works.

 

[Marius A]

I wouldn't say it's "easy" to make serious mistakes if you use a reasonable amount of self-awareness about what you are doing. It's actually pretty easy to install it correctly, just don't think it's like snapping two Lego blocks together - it does take more awareness than that.

Can you propose a mounting system that would be as sleek and robust but even easier to install? Without adding significant expense to the vast majority of cars that never have racks mounted? Please post the improved solution below and I'll forward it to Tesla for their consideration. Well, if I think it's an improvement.

The full glass roof definitely limits the available options. I like the chosen solution because Tesla didn't choose an expensive and overly engineered solution, just a simple and sleek one that works.

A T-bolt which can be twisted into an X? I don't know, I'm not a mechanical engineer. What I do know is that the J-bolt is not self-supporting, so the rubber casing decides the angle it ends up in. If they had a hook-and-latch system you wouldn't have to double/triple/quadruple check each side before tightening.
I did, mine where apparently not mounted wrong, though I don't know how the PPF made it crack.

The solution is good, but it is not very user friendly. That's why I said it's not well-engineered. It is robust, for sure, and safe. Even if you crack the roof there is no chance of the ski box falling off or crashing into traffic (unless you put the jbolt underneath the glass, which it specifically says not to do. I'm filing that scenario under Darwin).

 

[Nuclear Fusion]

I did, mine where apparently not mounted wrong, though I don't know how the PPF made it crack.

I haven’t received mine yet, so can’t visualise to comment adequately, but the PPF issue is concerning
Tesla is either using the PPF as a cop out for poor design or it actually causes the pads to slide into glass
I plan on loading the roof bars to their weight limit, but with a third mounting ‘T’ support off the hitch
See my Model X for visual explanation:
SeaSucker Monkey Bars (roof bars)

 

[640k]

yes...here’s a pic of the welded retainers we are talking about.
View attachment 481593 View attachment 481594

you know, after seeing this, there's basically only "one place" the hooks can possibly go. how are these getting installed wrong?

 

[CharleyBC]

you know, after seeing this, there's basically only "one place" the hooks can possibly go. how are these getting installed wrong?

Guessing: Not getting the hook down deep enough, so it’s above that receptacle and directly grips the glass instead.

 

[N54TT]

you know, after seeing this, there's basically only "one place" the hooks can possibly go. how are these getting installed wrong?

Not really sure. Not following the instructions? good question for the original poster .

OEM TESLA roof racks Crack Glass

 

[Marius A]

you know, after seeing this, there's basically only "one place" the hooks can possibly go. how are these getting installed wrong?

It's a J-shape, it can tilt inward. That's why it usually breaks, because it needs to point straight up to prevent the rubber pad from pressing down on the glass.
Combine that with crap build quality where the glass is off-centre and eschew. It's not surprising that people mamage to crack it by mistake, it's a design which doesn't forgive anything.