Power Steering falling apart

[Brass Guy]

Interesting update:
I stopped by the service center last night so I could discuss this in person. I was introduced to a technician on the shop floor.
He said he's seen this quite often. Sometimes the assist motor is just hanging there.
I asked how old or how many miles these cars have, he replied that sometimes its around 30k miles; so at 110k I did pretty well.
He speculated that whether the car is kept in a garage or not (mine is) is probably a consideration.

This confirms that it really wasn't likely anything I did or how I drove, but now I'm even more concerned that this is a wide-spread safety issue.

 

[appleguru]

Interesting update:
I stopped by the service center last night so I could discuss this in person. I was introduced to a technician on the shop floor.
He said he's seen this quite often. Sometimes the assist motor is just hanging there.
I asked how old or how many miles these cars have, he replied that sometimes its around 30k miles; so at 110k I did pretty well.
He speculated that whether the car is kept in a garage or not (mine is) is probably a consideration.

This confirms that it really wasn't likely anything I did or how I drove, but now I'm even more concerned that this is a wide-spread safety issue.

Sounds like they need to add “remove steering assist bolts, inspect, clean/replace if damaged, loctite, replace” to their 2yr service interval...

 

[TSLA Pilot]

This needs to be escalated within Tesla ASAP; it's an obvious design or assembly flaw that is compromising a basic function: STEERING. The tech's comments are completely unsat as he appears to be treating this as if it was a minor issue with a coat hook (not that we have those, of course).

Please get over to SaferCar.gov and file a NHTSA complaint ASAP. Thanks.

 

[Az_Rael]

Interesting update:
I stopped by the service center last night so I could discuss this in person. I was introduced to a technician on the shop floor.
He said he's seen this quite often. Sometimes the assist motor is just hanging there.
I asked how old or how many miles these cars have, he replied that sometimes its around 30k miles; so at 110k I did pretty well.
He speculated that whether the car is kept in a garage or not (mine is) is probably a consideration.

This confirms that it really wasn't likely anything I did or how I drove, but now I'm even more concerned that this is a wide-spread safety issue.

Dang, this makes me wish I had asked more questions when mine failed at around 30k on our P85D shortly after buying the car. It was a CPO from Connecticut so it’s possible it wasn’t garage kept.


So, how easy is that part to see if you pull out the frunk cover? Like if I wanted to check my P85? You saw a backed out sheared bolt, correct?

 

[mongo]

Interesting update:
I stopped by the service center last night so I could discuss this in person. I was introduced to a technician on the shop floor.
He said he's seen this quite often. Sometimes the assist motor is just hanging there.
I asked how old or how many miles these cars have, he replied that sometimes its around 30k miles; so at 110k I did pretty well.
He speculated that whether the car is kept in a garage or not (mine is) is probably a consideration.

This confirms that it really wasn't likely anything I did or how I drove, but now I'm even more concerned that this is a wide-spread safety issue.

From your previous message:

He thanked me for the pictures and information. He suggested the gasket may be compromised, this may happen again, and they recommend replacement.

I wonder if the gasket is breaking down, that would remove the loading on the attachments bolts and allow them to back off. Did you happen to notice the state of the gasket during your repairs?

 

[Brass Guy]

@TSLA Pilot - I don't blame the tech at all. Techs probably show or explain to the service manager the issue, then get authorization to repair (replace). Their responsibility should end there.
Service managers however should have pushed this up the chain. Even if they don't, parts in CA should notice that service centers are ordering steering racks and should investigate why. This is why I was asking if there was a service bulletin. (Never got a "yes" or "no" now that I think about it.) IMO, the part should be upgraded (maybe it has) and all older ones should be replaced by Tesla, like they did with so many of the contactors.

@Az_Rael - Yes, with a car that has the large front trunk, it'll be very easy to see if you take out the tub. My first picture is from the front bumper looking aft. The motor is probably 4~5" in diameter. The bolts are round head torx.
How did yours fail? When we were troubleshooting it, a message came up on the IC indicating a steering assist problem, contact Tesla. Is that what happened?
As far as garage-kept, as I said that was mere speculation anyway. 30k miles - wow, just like the tech described.

@mongo - It's not a gasket, it is an O-ring. You can see it in my second picture, before I cleaned it. After I cleaned off the oxidation dust, it looked just about new and was still very flexible. It sits in a channel (with a square cross section) on the motor, so it compresses slightly when mated. It won't effect loading of the bolts. I cleaned out the channel and mating surface.

 

[mongo]

@mongo - It's not a gasket, it is an O-ring. You can see it in my second picture, before I cleaned it. After I cleaned off the oxidation dust, it looked just about new and was still very flexible. It sits in a channel (with a square cross section) on the motor, so it compresses slightly when mated. It won't effect loading of the bolts. I cleaned out the channel and mating surface.

Thanks! I see it for what it is now. That's a much better setup than a sandwiched full face gasket. Appreciate the response.

 

[Az_Rael]

How did yours fail? When we were troubleshooting it, a message came up on the IC indicating a steering assist problem, contact Tesla. Is that what happened?

No IC message. Just a stiff/loose pattern when turning the wheel while driving at low speeds. Reset the car, and it still behaved that way. Called roadside assistance and had it towed. During some part of the process, the fact that a gear was stripped was mentioned, but we didn't get any more details. So it's possible it wasn't the same failure mode, which is why I wish I had asked more questions in hindsight.

 

[mongo]

No IC message. Just a stiff/loose pattern when turning the wheel while driving at low speeds. Reset the car, and it still behaved that way. Called roadside assistance and had it towed. During some part of the process, the fact that a gear was stripped was mentioned, but we didn't get any more details. So it's possible it wasn't the same failure mode, which is why I wish I had asked more questions in hindsight.

Sounds like the rack side gear or the belt lost some teeth. That would allow it to work at certain orientations, but not others.

 

[mrElbe]

Parked my car in the driveway at noon today. Entered the car at 6pm and immediate message "Car needs service", "Auto Park not available", "Power steering " accompanied by awful noise and jerking when touching the steering wheel. removed the tub and Voila! the same problem as the original Poster.

Cleaned it and got 8mm bolts and did a beautiful re-attachment job and no more messages BUT when turning steering wheel, awful grinding noise. So the gear is worn.

 

[Brass Guy]

@mrElbe - actually mine did the same thing at first. I had just snugged up the bolts and tested it, same noise. Then I tightened each bolt a bit more and it was fine.

You can try feeling the belt for wear, the drive gear in your picture looks OK. It'd be nice to have torque specs. You have to be careful since the bolts are going into aluminum.

 

[davecolene0606]

Just curious, what has your maint inspection schedule been like? I have been doing annual service without regard to mileage. Typically I run about 28k per inspection and they do a full service. So I'm wondering if this is being missed during an inspection?

 

[TSLA Pilot]

Parked my car in the driveway at noon today. Entered the car at 6pm and immediate message "Car needs service", "Auto Park not available", "Power steering " accompanied by awful noise and jerking when touching the steering wheel. removed the tub and Voila! the same problem as the original Poster.
View attachment 263444

Cleaned it and got 8mm bolts and did a beautiful re-attachment job and no more messages BUT when turning steering wheel, awful grinding noise. So the gear is worn.
View attachment 263446

Okay. That's it.

These are no longer "one offs" but a pattern of serious problems affecting a key safety component: steering. Worst case, the oldest Model S is just over FIVE years old. This kind of wear and damage--major steering problems--is unsat for cars at ten or fifteen years old.

Tesla: Please get on this problem with a plan to recall the cars and replace these components proactively, before the inevitable bad press which will result from doing nothing, not to mention the safety implications should there be accidents. Obviously, this is very much a supplier issue and the supplier needs to step up and open their checkbook, and open it wide.

Having Tesla chime in on this thread would at least give us a bit of relief that HQ is both aware of the problem and taking steps to resolve . . . .

Thanks.

 

[mspohr]

Time to report this to NHTSA
File a Vehicle Safety Complaint | Safercar.gov | NHTSA

 

[mrElbe]

Just curious, what has your maint inspection schedule been like? I have been doing annual service without regard to mileage. Typically I run about 28k per inspection and they do a full service. So I'm wondering if this is being missed during an inspection?

I had just done an 80,000 km ( 50,000 mile ) service 2 weeks ago. I also complained about a slight grinding noise. Service replaced the rear motor but grinding noise was still there.

I now also reported it to NHTSA

 

[mrElbe]

Interesting observation. Just inspected a facelift 2016 75D and what do you know, they changed the steering rack to part number 1060801 and it has steel bolts instead of aluminum bolts holding the steering assist motor.

So does that mean that there is a problem with the earlier assemblies as we experienced. Should that not be a no charge pro-active replacement for such a safety related item.

 

[Brass Guy]

It looks like they are now using steel bolts to assemble the rack also.

 

[MP3Mike]

It'd be nice to have torque specs.

@Btr_ftw Do you happen to have the torque specs for these bolt available?

 

[cwerdna]

I had just done an 80,000 km ( 50,000 mile ) service 2 weeks ago. I also complained about a slight grinding noise. Service replaced the rear motor but grinding noise was still there.

I now also reported it to NHTSA

Since you're in Canada, perhaps https://www.tc.gc.ca/eng/motorvehiclesafety/reporting-defects-motor-vehicles.html is more appropriate for your case?

 

[appleguru]

Interesting observation. Just inspected a facelift 2016 75D and what do you know, they changed the steering rack to part number 1060801 and it has steel bolts instead of aluminum bolts holding the steering assist motor.
View attachment 264271 View attachment 264272

So does that mean that there is a problem with the earlier assemblies as we experienced. Should that not be a no charge pro-active replacement for such a safety related item.

Do we know what the steering rack housing is made out of? The good news is the 'new' screws appear to be coated; if they weren't I would have pretty big concerns about corrosion due to dissimilar metals.

Regarding torque specs, I don't think the bolts in question are intended to be serviceable... Pretty sure Tesla advises replacing the entire rack. So not sure we have/can get them (unless someone knows/reaches out to the rack OEM and asks?)