Front Driver's Steering Knuckle FRACTURED while driving at 55mph [Video]

[ChefAries]

Driving on the Expressway, and a huge BANG violently shook the car, as if I ran over a huge pothole, knocking my dashcam off its suction mount. Luckily I was able to keep it under control and pulled it to the shoulder. I get out and see the left side of my car is slammed to the ground, and the fender is riding on the tire.

I limp it to a safer spot in a nearby parking lot, and take a look. The Steering Knuckle Casting is Fractured at the bottom of the air spring! Tesla Roadside says they see nothing remotely wrong with my car, so I'll need to pay for the Tow myself.

I haven't heard of this before, and it doesn't seem common. I'm assuming a casting defect caused a crack that propagated into a complete fracture. Luckily my dashcam shows that this wasn't caused by hitting anything, as I'm sure that's the likely reason SC would give for a casting to fracture like that.

35k mi, 2016 P90D

Dashcam Video:

 

[Ostrichsak]

It seems silly that Tesla assumes ALL problems can be diagnosed remotely and if it isn't you're stuck with the tow bill. These cars are advanced but they're going to need a LOT more advancement before they take such a stand on stranded cars under warranty. That's pretty absurd for a qualifier and one more example of how terrible Tesla "Customer Service" support has become over the years. Get ready for them to refuse warranty coverage due to your spirited driving or hitting a pothole previously that surely cased said damage. I bet they'll blame the number of launches you've done or your charging habits if that doesn't work.

 

[ChefAries]

Just got off the phone with SC, and they said an aftermarket sensor was installed to make it go lower than spec (?). I purchased this as a CPO directly from them about 9-10 months ago, and didn't install any aftermarket sensor, but kept it on "ALWAYS LOW" on the suspension settings.

Here's a pic from April with my winter wheels on. Doesn't look like it's sitting lower than stock, does it? I'm pushing back on them, because they sold the car to me like this. They are reviewing with their sales team.

 

[MP3Mike]

Luckily my dashcam shows that this wasn't caused by hitting anything, as I'm sure that's the likely reason SC would give for a casting to fracture like that.

Actually it looks like it happened right as you hit a joint in the freeway at 4 seconds in to your video. It doesn't look like that joint has a big hole in it, but it looks like you were still completing your lane change so the wheels might have been over a section of that joint that isn't the normal travel path.

Not that that should change anything, unless it is a major hole. (In which case the state might be responsible for repairs.)

 

[Ostrichsak]

Just got off the phone with SC, and they said an aftermarket sensor was installed to make it go lower than spec (?). I purchased this as a CPO directly from them about 9-10 months ago, and didn't install any aftermarket sensor, but kept it on "ALWAYS LOW" on the suspension settings.

Here's a pic from April with my winter wheels on. Doesn't look like it's sitting lower than stock, does it? I'm pushing back on them, because they sold the car to me like this. They are reviewing with their sales team.

Ah yes, the classic "you replaced an aftermarket sensor that caused a major suspension component failure" scapegoat that Tesla deploys so skillfully. ROFL

 

[ChefAries]

Phew, they called back and said that they should have caught the aftermarket sensor when they sold it to me. And since they didn't, they're going to cover it under warranty. The estimate was about $6k, including new air spring, new brake lines, new sensors, and a new wheel/tire.

I'm still not sure how a sensor causes a casting to catastrophically fail, but I'm now worried that it'll happen again on the other wheels eventually since they said the sensor was changed on all 4 corners.

 

[MP3Mike]

Phew, they called back and said that they should have caught the aftermarket sensor when they sold it to me. And since they didn't, they're going to cover it under warranty. The estimate was about $6k, including new air spring, new brake lines, new sensors, and a new wheel/tire.

I'm still not sure how a sensor causes a casting to catastrophically fail, but I'm now worried that it'll happen again on the other wheels eventually since they said the sensor was changed on all 4 corners.

Well they did say new sensors so I assume that they are replacing all 4 of them. (They really need to be a matched set.)

I assume that by lowering the car it changes the geometry and put excessive stress on some parts.

It will be interesting once you get it back to see how much higher it is. (If any higher.)

 

[Ostrichsak]

Phew, they called back and said that they should have caught the aftermarket sensor when they sold it to me. And since they didn't, they're going to cover it under warranty. The estimate was about $6k, including new air spring, new brake lines, new sensors, and a new wheel/tire.

I'm still not sure how a sensor causes a casting to catastrophically fail, but I'm now worried that it'll happen again on the other wheels eventually since they said the sensor was changed on all 4 corners.

I guess that "70-point inspection" Tesla sells us doesn't cover any aspects of the suspension, brakes or related electronics. Yikes!

Good thing those aren't important aspects of a car or anything.

 

[maximizese]

Glad you seem to be on the right path with Tesla and they are doing the right thing...after doing the wrong thing. From my understanding the original SAS cars sat at a lower height during the early production of the Model S, but they were raised through software after having a few issues with abnormal tire wear and road debris damage. In addition, Tesla improved the underside protection and retrofitted sold Model Ss to prevent the HV battery. Perhaps extended time driven on "Very low" would compromise the steering knuckle, perhaps it's the snow/road salt/humidity that weakens the components over time, it might have been a defective part, or just a fluke.

Thanks for sharing and I'll be sure to add that to my list of things to inspect as my car ages.

 

[Evee]

oh man im glad ur safe id be like WTF. my car has almost 125k miles now lol

 

[Cheburashka]

I'm also curious how a theoretically lower riding car would cause the terminal failure of the steering knuckle like that. My guess is that it was a manufacturing defect.

 

[ThomasD]

There is no way a wheel speed sensor caused that. If that wasn't due to impact then I would say the part was defective. My answer to you have to pay for it would have been Ok give me the parts back and I will send them out for NDI testing

 

[1965Falcon]

There is no way a wheel speed sensor caused that. If that wasn't due to impact then I would say the part was defective. My answer to you have to pay for it would have been Ok give me the parts back and I will send them out for NDI testing

It would be the height sensor, not the speed sensor. The aftermarket fools the car into thinking it's higher and allows a lower drop... which means less cushion to the suspension and more chance of damage.

 

[FlanManSD]

Make sure to ask for a credit on the tow bill if they haven't offered already. This is typical for warranty service and all reputable service shops will honor this. :^)

 

[DvLang]

I guess that "70-point inspection" Tesla sells us doesn't cover any aspects of the suspension, brakes or related electronics. Yikes!

Good thing those aren't important aspects of a car or anything.

I would make sure to set the car to low like you had it before and see if there is any difference. Although they have owned up to it, and are doing the repair. It would give you peace of mind on calling them on their BS.

 

[HankLloydRight]

Actually it looks like it happened right as you hit a joint in the freeway at 4 seconds in to your video. It doesn't look like that joint has a big hole in it, but it looks like you were still completing your lane change so the wheels might have been over a section of that joint that isn't the normal travel path.

If you watch closely, the steering knuckle breaks a fraction of a second before he gets to the road joint. It's very close, but you can hear the sound just as the road joint disappears under the car and before the wheels would have hit it.

 

[pamich10]

Driving on the Expressway, and a huge BANG violently shook the car, as if I ran over a huge pothole, knocking my dashcam off its suction mount. Luckily I was able to keep it under control and pulled it to the shoulder. I get out and see the left side of my car is slammed to the ground, and the fender is riding on the tire.

I limp it to a safer spot in a nearby parking lot, and take a look. The Steering Knuckle Casting is Fractured at the bottom of the air spring! Tesla Roadside says they see nothing remotely wrong with my car, so I'll need to pay for the Tow myself.

I haven't heard of this before, and it doesn't seem common. I'm assuming a casting defect caused a crack that propagated into a complete fracture. Luckily my dashcam shows that this wasn't caused by hitting anything, as I'm sure that's the likely reason SC would give for a casting to fracture like that.

35k mi, 2016 P90D

Dashcam Video:

Wow, it hurt just watching that! I am not sure if you have aftermarket suspension as the vehicle looks really low but I would take that to the DOT and have them pay for any damage. A pot hole that bad should not be tolerated. Good luck!

 

[MilesAhead]

Driving on the Expressway, and a huge BANG violently shook the car, as if I ran over a huge pothole, knocking my dashcam off its suction mount. Luckily I was able to keep it under control and pulled it to the shoulder. I get out and see the left side of my car is slammed to the ground, and the fender is riding on the tire.

I limp it to a safer spot in a nearby parking lot, and take a look. The Steering Knuckle Casting is Fractured at the bottom of the air spring! Tesla Roadside says they see nothing remotely wrong with my car, so I'll need to pay for the Tow myself.

I haven't heard of this before, and it doesn't seem common. I'm assuming a casting defect caused a crack that propagated into a complete fracture. Luckily my dashcam shows that this wasn't caused by hitting anything, as I'm sure that's the likely reason SC would give for a casting to fracture like that.

35k mi, 2016 P90D

Dashcam Video:

I'm Glad you are ok!

 

[George Marley]

I'm guessing you'll be filing a report with NHTSA?

 

[SoCal Buzz]

Nice job keeping the car under control. That was a pretty severe jolt. And I'm glad Tesla is covering the repairs for you.