Maybe u went over weight limit. Worked fine with 4 pairs of skiis

 

Load rating is 150 lbs (reference).

 

There is a discussion about this on Reddit, which also includes a link to a discussion elsewhere with multiple reports.

Warning : Model 3 Roof Rack can easily break, fall off car while driving

 

The broken piece doesn’t look like it’s been flexing. Maybe the bolt was over-tightened? This might just have to do with Tesla needing to revise the maximum torque specification for the boots.

 

@TesLou while the rack was installed, at any time did it or something installed on it impact anything? IE scraping in a parking garage?

 

There was ZERO load on the bars and there has been no excessive pressure put upon them (other than me giving a minor tug a couple of times to ensure they were secure). I hand tightened them very gingerly when I installed them a week ago. It was cold when we left home yesterday morning and it was gradually warming up as we got further south.

 

Sorry to hear.

Lots of discussion about this over the the other Tesla forums (since late December or so). Latest working theory has something to do with 1st vs 2nd/newer batch of these, people scrambling to find part numbers, etc.

 

That bracket looks like it’s been cast (vs. stamped). We should have some people here with the expertise to verify. Not saying cast is bad but you generally don’t see that type of failure with stamped, especially in such a short time frame.

 

That bracket looks like it's been cast (vs. stamped). We should have some people here with the expertise to verify. Not saying cast is bad but you generally don't see that type of failure with stamped, especially in such a short time frame.

Yeah; it has a weird and cheap feel to it. The wing nuts do, as well. I'm sure I have second gen since I've only had this for a couple of weeks.

 

I posted a YouTube video when I installed this last weekend for anyone who cares to be bored to death.

 

It’s the Comet story all over again, square windows with stress cracks forming from the corners.

 

It's the Comet story all over again, square windows with stress cracks forming from the corners.

Very few will get this. I do.

 

https://aerospaceengineeringblog.com/dehavilland-comet-crash/

 

The latest theory from another forum post is that the j-bolt on one of the batch with a rectangle hole in the middle and those are the one that are snapping. It was built this way to extend the screw thread out a bit mor.

 

Not only do I get the Comet reference, my PhD thesis was in the field of fatigue cracking and my career was in aviation.

The flat piece looks like a stamping to me - I can see from the sheared edges that it was punched out of a plate, then bent. The threaded part was made separately and (poorly) welded to the flat piece. Since it was not fully inserted into the slot before welding, it left a rectangular opening, the corner of which puts a stress riser directly on the weld.

Amateurishly designed, or someone took a bunch of incorrectly manufactured bits and used them anyway - the round piece was supposed to bottom out in the slot a be welded all around.

Still a bit puzzling that it broke. Was there misalignment? Fit-up stress? Salt? (Stress corrosion cracking).

 

Not only do I get the Comet reference, my PhD thesis was in the field of fatigue cracking and my career was in aviation.

The flat piece looks like a stamping to me - I can see from the sheared edges that it was punched out of a plate, then bent. The threaded part was made separately and (poorly) welded to the flat piece. Since it was not fully inserted into the slot before welding, it left a rectangular opening, the corner of which puts a stress riser directly on the weld.

Amateurishly designed, or someone took a bunch of incorrectly manufactured bits and used them anyway - the round piece was supposed to bottom out in the slot a be welded all around.

Still a bit puzzling that it broke. Was there misalignment? Fit-up stress? Salt? (Stress corrosion cracking).

No misalignment and no stress; other than the normal stress associated with holding the bolts in place. One thing I found that concerned me was the amount of water beneath the end caps (where the nuts and bolts reside). I think in time that may have caused issues of another kind.

 

The roof racks that were supplied for my (now lonely) Macan came with a torque screwdriver for the SS socket head mounting bolts. German engineers like this sort of thing. Much better than "Do not over-tighten". (They never complete the instructions: "Do not under-tighten, either. Tighten just right. Good luck.") Teslou: did you tighten them just right?

 

The roof racks that were supplied for my (now lonely) Macan came with a torque screwdriver for the SS socket head mounting bolts. German engineers like this sort of thing. Much better than "Do not over-tighten". (They never complete the instructions: "Do not under-tighten, either. Tighten just right. Good luck.") Teslou: did you tighten them just right?

Haha...apparently not. I did try to use a torque wrench (see my YouTube vid) but the 8 nm the specs call for were much less than the wrench could accurately measure. But the fact that you're snugging this up around an expensive piece of glass is enough to make you gingerly turn the nuts no more than necessary. Or that's what you hope, anyway.

 

I was surprised when attaching the rack to my P3D+ when one of the clips broke at just 50 in lbs of torque which is only 5.65 nm of the suggested 8 +/- 1 nm in the instructions. They had me send the whole thing back and I haven’t heard anything since. I think the plan is to re-engineer the method of attachment and send me the re-engineered/redesigned version because nothing was said about a refund.

 

I was surprised when attaching the rack to my P3D+ when one of the clips broke at just 50 in lbs of torque

You probably did, but I just want to check - are you sure your torque wrench was measuring in-lbs and not lbs-ft?
50 lbs*ft would be about 68 Nm.

 

I received new j-bolts from Tesla today. I was encouraged when I saw the return address was actually from the Yakima Company. But when I opened the package, it was a bit disheartening to discover the new bolt is basically the same structure as the old (with the gap still remaining at the attach point). The only difference is the silver color. I'm no metallurgist but this "new" bolt doesn't 'feel' any more hardened than the other one. I can't say I'm very confident about reinstalling the rack on my car. I was also surprised about the speed in which this new bolt arrived. Personally, I would have been happy to wait a while longer for a complete redesign of the attachment method and reforging of the hardware.

 

Yeah; that sounds like a good plan. Stay tuned...

 

We had a successful trip to the mountains with our big Thule box on the revised connectors (110 mi each way in 0 deg F weather). Racks have stayed on since winter with no issues.

 

Whew! That's a huge relief hear.

 

Hi, the roof rack is great. I transported my ski box on it. Only issue: the vinyl pads are not something to keep. After taking the rack off my model 3, i threw away the protective vinyl items.

Question: has anybody found replacement protective vinyl pads (the thin translucent vinyl stickers is what I mean, to put directly on your paint, to protect the paint).
I looked only, but cannot find it anywhere.