Be aware! Missing Control Arm Nut: Potential Safety Issue

[kavyboy]

C'mon now, are you saying that Tesla shouldn't be using this product in this application? Don't you think they spec all of this stuff out with the manufacturer prior to using them, and determining that the application is within spec for the part?

Like the screens? And the memory chips?

 

[Balthezor]

Glad you are ok. I have a Model Y on order and this worries me. I am letting my SA know to about this thread and will remind him to check it again when I pick up the vehicle.

I also tweeted this thread to Ryan McCaffrey, host of Ride the Lightning podcast. He has a lot of listeners that may work at Tesla. And he may tweet Elon as well to maybe look into it.

 

[DanDi58]

If you watch the videos there is a very clear explanation of why the regular Nord-lock washers are unsuitable for this application and that the correct washer to use is the Nord-wedge.
The cost difference would be pennies.
I think Tesla has made a mistake.

Wouldn't you agree?

Perhaps it's not as clear as you think.... I'm not an engineer but seems like this might be similar usage, if not maybe more extreme... https://www.nord-lock.com/en-us/insights/customer-cases/2015/rallying-for-safe-bolted-joints/

 

[AJB123]

If you watch the videos there is a very clear explanation of why the regular Nord-lock washers are unsuitable for this application and that the correct washer to use is the Nord-wedge.
The cost difference would be pennies.
I think Tesla has made a mistake.

Wouldn't you agree?

I'm not understanding what "regular Nord-lock" is compared to the wedge. I thought that video was talking about the wedge washer. But either way when they say "soft" I think they mean rubber or wood - cast aluminium should be hard enough for the washer to dig into, and I don't imagine that nut will be tensioning against rubber - it'll be clamping up metal on metal. So to me that video isn't saying it's not suitable.

But clearly they've got something very wrong - either design or, more likely, assembly. It's almost weird they've used a lock washer AND a nylock nut - everything I've worked on has been one or the other - so they must be worried about it coming loose in their design. Perhaps if it comes a bit loose, then rotation of the steering allows the nut to get driven off as the bolt rotates and the nylock doesn't hold in place.

 

[Raro]

For those of you who go to put a wrench on this, if it’s loose don’t just tighten it up and call it good, the control arm joint sits in a taper in the knuckle arm. If it’s been beating back and forth it has probably done damage to the taper and won’t seat properly anymore, and could work it’s way loose again.

 

[Dennisis]

Your experience with your car does not mean that is representative of overall build quality. My experience with my Model 3 (88k miles and counting) has been the exact opposite. With the exception of the stinky AC issue I have had zero defects / panel gap problems / paint problems etc. The car has been darn near perfect. What you and I have are conflicting anecdotal stories. We need statistically relevant data before we can draw a conclusion like “they throw these things together” or “highest quality american made car.”

Ditto - M3 now MY, minor issues. Such is the rush to judgement driven by paranoia and easy access to message boards, especially with life disrupted by the virus. Any problem or incident gets magnified almost instantly. Safety issues get up channeled quickly with any manufacturer, I’m sure it won’t take some YouTuber to rescue anyone.

 

[BlindPass]

Typical of the new Tesla imo. It is hard to contain haste.

 

[G26okie]

Torque spec on that nut (lower lateral link to knuckle) from the Model 3 service manual is 180 NM or 133 ft-lb. Should be the same on the Y.

Do you know the proper way to torque these? The bolt itself has the torx female end and the nut sits on that end. Can I just get a deep socket on the nut and torque it?

 

[DanDi58]

Do you know the proper way to torque these? The bolt itself has the torx female end and the nut sits on that end. Can I just get a deep socket on the nut and torque it?

I would not. Any failure then would be YOUR fault. If I saw this on my car, I would call SC and say, send a tow truck to get this car. It's not worth the potential risk to mess around with it....

 

[1965Falcon]

Do you know the proper way to torque these? The bolt itself has the torx female end and the nut sits on that end. Can I just get a deep socket on the nut and torque it?

If you find any evidence that yours are loose, then as mentioned above they will need to be inspected for damage, don't just tighten it back up. If you are just checking to make sure it's torqued to specification then yes. The torx is to keep the ball joint shaft from spinning. I haven't looked but sometimes these are offset to allow for alignment adjustment as well... so don't loosen and spin it around at all.

**edit, anyone doing this does accept all liability if anything is damaged. I would do this only if you are confident and know how to use a torque wrench. My recommendation if you are really worried, take it to a service center and have them check the torque.

 

[destructure00]

Do you know the proper way to torque these? The bolt itself has the torx female end and the nut sits on that end. Can I just get a deep socket on the nut and torque it?

I just used a socket on the nut. Did not bother with the torx female end, and didn't have any issues with the ball joint stud spinning.

 

[G26okie]

If you find any evidence that yours are loose, then as mentioned above they will need to be inspected for damage, don't just tighten it back up. If you are just checking to make sure it's torqued to specification then yes. The torx is to keep the ball joint shaft from spinning. I haven't looked but sometimes these are offset to allow for alignment adjustment as well... so don't loosen and spin it around at all.

Mine are pretty tight, tried with a big adjustable wrench before taking the wheel off and they won't budge, just wanted to get my actualy torque wrench on them to make sure.

 

[CyberGus]

If you find any evidence that yours are loose, then as mentioned above they will need to be inspected for damage, don't just tighten it back up.

Right. If some of these fasteners are insufficiently torqued, then it is fine to torque them to the correct spec unless they are already loose. If they have backed out enough for your suspension to go clunk then there could be damage.

 

[Joelgjr]

this is insane

 

[G26okie]

this is insane

I'm doing more work on my tesla to make sure it is actually put together properly than on an ice car lol.

 

[LevelHeaded]

No idea how and where to check this, but Tesla has done an alignment on my MY so I'm assuming they would have noticed it...

I checked mine and all the bolts are present. VIN 18XXX

 

[NY_Rob]

You can see from the witness marks on the failed joints that the nuts were torqued, but never correctly/sufficiently.

I'm not seeing any witness marks on the failed joint.. can you point it out please? Are you referring to the galling inside the nut seat?

 

[G26okie]

Just got done checking my p3d.

I'm not seeing any witness marks on the failed joint.. can you point it out please? Are you referring to the galling inside the nut seat?

Yeah the galling on the nut seat.

I just checked my model 3, the most forward bolt was slightly under spec on both sides, not anywhere near loose but it did turn very slightly before 133ft lbs. The one pictured coming loose in this thread was at least at spec. I also checked the tie rod to knuckle and I could not get my wrench to click, it wasn't loose but the steering rack turning was taking up too much slack.

 

[Bueno]

I'm not seeing any witness marks on the failed joint.. can you point it out please? Are you referring to the galling inside the nut seat?

The witness marks are the thin pattern on the face of where the nut would seat against the spindle. This does not mean the nut was even tightened. It does show that it was there but not necessarily tight. If the nut was even torqued at all there would be witness marks all the way around the face of the mating surface of the base of the nut and the spindle.

The design of having the ball joint nut facing towards the floor helps prevent the car falling when stuff like this happens. Not say its ok at all for this to happen. If the control arm met the spindle from the bottom with the nut facing the sky as soon as the nut came off then the car would have dropped to the ground.

 

[newtnyc]

For those of who are clueless about these things but worry about it nonetheless. Is there a less than obvious symptom that should be of concern. I noticed yesterday that the alignment is off. Car pulls to the slight right when the steering is at 12 o clock.