Statistical poll of the drive unit issue

[marcad80]

Noise doesnt mean failure. There are many noises that Tesla drive units make, and some are purely cosmetic. How in the world can you differentiate between all of these variables? You can't.

The term noise above was referring to data noise, not vehicle noise. As in Signal to Noise ratio, averaging is a very good way to get to signal. Noise is random and averages itself out.

As to the noise I think you are referring to, you are correct, in a simple two degree of freedom poll I tried to isolate the variables I thought I could get the most information out of. The different types of failures in the Drive Unit are not isolated here and I was quite surprised that it appears that they are directly related in that the failed data doesn't appear to be bi model or random.

 

[qwk]

I think you are having trouble understanding me. Somebody that has had their DU unit replaced for noise will click on your poll, because that's just what happens. Times that by who knows how many people, and now you have a bunch of useless data. You seem to be running with that useless, and inaccurate data, and coming to completely wrong conclusions. Only Tesla knows how many Drive Units have had real trouble, and no amount of polling data will change that.

 

[supratachophobia]

I think you are having trouble understanding me. Somebody that has had their DU unit replaced for noise will click on your poll, because that's just what happens. Times that by who knows how many people, and now you have a bunch of useless data. You seem to be running with that useless, and inaccurate data, and coming to completely wrong conclusions. Only Tesla knows how many Drive Units have had real trouble, and no amount of polling data will change that.

Which is why I would like feedback on the whining nose if it was heard over the miles prior to drive unit failure. The whining noise is coming from degradation of something so therefore it's still valid as a cause for drive unit replacement.

 

[qwk]

Which is why I would like feedback on the whining nose if it was heard over the miles prior to drive unit failure. The whining noise is coming from degradation of something so therefore it's still valid as a cause for drive unit replacement.

Mine has had a noise for over 30k miles with no issues. It doesn't bother me. There are also many different noises that different DU's have(something else to consider).

 

[supratachophobia]

Mine has had a noise for over 30k miles with no issues. It doesn't bother me. There are also many different noises that different DU's have(something else to consider).

Then it can't be the same noise. The whining I'm talking about gets progressively worse and can be heard very well in the cabin to the point where passengers ask "what is that noise". Also, it causes pedestrians to get out of the way so you know that's not normal.

 

[cwerdna]

Besides the many questions/issues raised, what counts as "failure"? I'd imagine that many people getting theirs replaced for noise aren't counting those as "failures" but some are...

Judging by what I've seen here, I have serious doubts that anyone w/a Model S who answered "No unit failure, 75-90k miles" actually is on their on their original drive unit. I suspect they've had at least 1, maybe 2 swaps out for noise.

I also am somewhat doubtful that the person who answered "No unit failure, 45-60k miles" is on their original DU.

I have said this before, and I'll say it again. You don't even own a Model S, yet you come to all of these conclusions? Noise isn't a failure, just a nuisance. One sees a lot more being in the game vs. sitting on the bleachers.....

Re: the bolded part, that's exactly why I asked the first question.

Yeah, I'd tend to agree that DU's replaced for noise aren't failures.

But, if they install a new or reman DU, the clock has essentially started over. For the Edmunds case, they had one total failure, but yet they had their DU replaced 3 times (noise at 10.7K miles, total failure at 18.8K miles, noise at 30K miles). No DU ever of theirs experienced more than 12K miles before getting swapped out. Then they sold their car.

I'm not sure what "One sees a lot more being in the game vs. sitting on the bleachers" is supposed to mean. It doesn't change the fact that there are numerous DUs being replaced due to noise and some (seemingly fewer) replaced due to failure. It's not surprising the Tesla-supplied drive unit in RAV4 EVs seems to have the same symptoms of noise, requiring DU replacement.

I'm not a Tesla fanboy, defender nor apologist for them. There are some here who have drank the Kool-Aid and seem rather dismissive of these issues or defend them.

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Your assertion is absurd.
You do not have access to any statistically valid data on which to base such a statement. You are extrapolating -- wildly -- from posts in online forums by owners complaining about noise they think may be coming from the drivetrain in their car. Are they hearing a noise? They certainly are. Do they have an accurate sense of what that noise means and it's true source? No they do not. They are owners, not Tesla service personnel.

There are MANY of the above owners who HAVE gotten their drive units replaced for noise by Tesla service centers, sometimes repeatedly. I can dig up probably at least dozen cases of replacement due to noise.

Online forum posts about vehicle issues cannot be used to accurately determine what percentage of owners are having a problem with a specific part in a vehicle. Owners not having problems are not posting to say that "today I didn't hear a noise in my drivetrain and I'll post again tomorrow if I don't hear a noise".
Your reasoning is specious and your conclusions are unsupportable.

I'm Leaf driver and have been following the Leaf since before it went on sale in December 2010, including having test driven one before they went on sale. I've seen what reliable looks like (e.g. Leaf (pretty decent) and Priuses, from Gen 2 and beyond, which have excellent reliability records). It's almost unheard to have a motor replaced on a Leaf for ANY reason even once, be it noise or failure, despite a far larger population of Leafs than there are Model S and them being on the market longer.

Priuses sure don't have repeated replacements of transaxles or engines within say 100K miles. Even an owner requiring a replacement of either within that mileage is pretty much unheard of. And, there have been millions of Priuses sold (Green Car Congress: Worldwide sales of Toyota Corp. hybrids top 7 million; Prius family accounts for 67.8%).

If it was indeed "rare" for a Model S to go for 30K miles without having a serious drivetrain issue, or even a noise that required a service visit, the company would long ago have collapsed under the weight of overwhelmingly negative news reports and falling sales..

Sure seems rare. The problem is, for whatever reason, there hasn't been much press coverage or word of mouth. I've spoken to a # of folks at my work who kinda want a Model S or like them and when I tell them about this, they don't believe me. I then forward them at least 1/2 dozen links of DU replacements due to noise, included repeated ones + the Edmunds long-term wrap up (2013 Tesla Model S Long-Term Wrap-Up | Edmunds.com)...

If those folks actually dug into these things...

As for "company would long ago have collapsed...", I stopped tracking long ago, but TSLA, when I stopped counting has accumulated over $1 billion in net losses.

 

[Ben W]

Not sure if this helps, but here is the serial number of my last DU installed in February. Service confirmed that it was BRAND NEW from the factory, not remanufactured:

ASY,P-TRAIN,SPORT,MECH,COMPLETE
(1002633-01-M)

I'd be curious to know if anything can be gleaned from the above?

I just had my drive unit fail completely on the freeway, and it was replaced by the Van Nuys SC. My car is a P85 Sig (VIN 00061, 30k miles), and the replacement part # was 1002633-01-P. (New, not refurbished.) They also replaced the side motor mount assembly: 1028034-1-00-B.

So far so good, hoping the new drive unit lasts a lot longer than the original one!!

 

[glhs272]

Mine has had a noise for over 30k miles with no issues. It doesn't bother me. There are also many different noises that different DU's have(something else to consider).

Respectfully, drive units being replaced due to noise are failures. I agree there are a lot of noises that the drive unit can make, and not all of them are an indication of failure. A mature inverter will make more noise than a new one, that's normal and nothing wrong with that. Early on, Tesla was replacing drive units when the problem really wasn't the drive unit.

Fast forward today. Tesla has gone through a lot of drive unit replacements. They know which ones are due to fail. They are replacing them before they fail outright. The noise I am talking about is the infamous "milling noise". The root cause of the milling noise is the rotor bearings are becoming pitted. This will lead to failure... eventually. The reason for this failure mode is well understood long before Tesla was even designing the drive unit for the Model S (why I really consider this a huge f*** up on Tesla engineering's part). Electrostatic discharge through rotor bearings has been a challenge for AC induction motors with Variable Frequency Drives for a long time. It is because of poor rotor grounding. VFD induction motors have to have good rotor grounding due to high frequency switching inverter. This phenomena is well documented on the internet, so I don't feel the need to post all the references like this http://sustainablemfr.com/energy-efficiency/bearing-protection-induction-motors-bears-attention. The point is there is actually something wrong with these drive units experiencing this issue and Tesla is doing right by replacing them. However, it is very frustrating to us owners with multiple drive unit replacements (such as myself) that they have been unable to completely eliminate the issue.

Why some drive units haven't been replaced yet? I don't know. I have to assume from the start that Tesla did provide some kind of rotor grounding, its just that their initial solution didn't work as well as hoped in all conditions. I take care of my car and don't abuse it and it still had multiple failures for the same issue. You say your car has made noise from the start, but is it the milling noise? If your car is beginning to make the milling noise, then you too will experience a failure. But you probably can run it for quite a while before it leaves you stranded on the side of the road. And frankly, until Tesla has really got this problem licked, might as well stretch out the replacement anyway...

 

[AmpedRealtor]

The root cause of the milling noise is the rotor bearings are becoming pitted. This will lead to failure... eventually. The reason for this failure mode is well understood long before Tesla was even designing the drive unit for the Model S (why I really consider this a huge f*** up on Tesla engineering's part). Electrostatic discharge through rotor bearings has been a challenge for AC induction motors with Variable Frequency Drives for a long time. It is because of poor rotor grounding. VFD induction motors have to have good rotor grounding due to high frequency switching inverter. This phenomena is well documented on the internet, so I don't feel the need to post all the references like this http://sustainablemfr.com/energy-efficiency/bearing-protection-induction-motors-bears-attention.

Has anyone at Tesla actually confirmed this to you, or are you hypothesizing? I have not read anything regarding Tesla stating that this is due to pitted rotor bearings. However, my droning noise above 65 MPH was described to me as a "bearing issue" by my service advisor - different symptom than the milling noise.

 

[glhs272]

Has anyone at Tesla actually confirmed this to you, or are you hypothesizing? I have not read anything regarding Tesla stating that this is due to pitted rotor bearings. However, my droning noise above 65 MPH was described to me as a "bearing issue" by my service advisor - different symptom than the milling noise.

Yes, but those are my words and recollection of a conversation and not in anyway documented. For the specific failure of my drive unit anyway. Said articles about this issue is just me adding color to the conversation to explain it better than I can. My judgement on Tesla's engineering may be a bit harsh. It (drive unit) has a lot of power in a small size, it's not quite as easy as it looks. This ain't no prius!

 

[William13]

I answered the poll as written. Noise caused replacement due to perceived failure by Tesla service. Two noises. Buzz from inverter that bothered me. My new one has developed the same noise also after 22,000 miles. The second more important noise was the clunk with the lag from the drive gear wear and tear. This has not yet recurred. I expect neither would cause failure before 150,000 miles, just bother me as I drive and ruin my "best day ever" everyday experience.

 

[Rule_of_72]

Had my first unit failure this last weekend at around 2,000 miles. New 70D model. Good news is the fix was a quick one as they had a unit on hand.

 

[wycolo]

Has Tesla been able to apply grounding rings to their motor shafts? Is there enough room to fit the rings in? Is there easy access to make this retrofit or does it require a complete tear down?

And what does 'singing bearing noise' have to do with 'inverter noise'? And why is inverter noise necessarily inevitable after xx miles - what happens in an inverter to cause vibration to occur after yy hours?

My particular milling noise ceases instantly upon transition into coast/regen. That would seem to rule out any bearing pitting type of wear.
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[glhs272]

My particular milling noise ceases instantly upon transition into coast/regen. That would seem to rule out any bearing pitting type of wear.
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Mine did too. I think that is an indication that the pitting happens on the outer race of the bearing on the side carrying the load. That would make sense in that the current is going to flow through the path of least resistance. The least resistance would be on the side most in contact with the balls/rollers (under pressure).

I have not done a teardown myself, so this is all based on an understanding of how this failure was explained to me and in combination of my own research on similar issues.

 

[Ingineer]

I purchased a new LEAF in 2011, and had zero issues with it. It's definitely a well-built car, but comparing the Model S to the LEAF as far as reliability isn't easy. For starters the Model S produces a LOT more torque and power, which leads to much larger stresses in the drive unit. Secondly, there is substantially more regen as well, which is negative torque on the geartrain. (harder to deal with)

I'm hoping Tesla has finally figured out the drive unit issues and fixed them. Have any owners of 2015 cars had a DU failure?

 

[Rule_of_72]

I purchased a new LEAF in 2011, and had zero issues with it. It's definitely a well-built car, but comparing the Model S to the LEAF as far as reliability isn't easy. For starters the Model S produces a LOT more torque and power, which leads to much larger stresses in the drive unit. Secondly, there is substantially more regen as well, which is negative torque on the geartrain. (harder to deal with)

I'm hoping Tesla has finally figured out the drive unit issues and fixed them. Have any owners of 2015 cars had a DU failure?

Yup, see my post a few above this one. I have a brand new 70D that just had a failure at a little over 2000 miles this past weekend.

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[Ingineer]

On large industrial AC induction motors they sometimes are equipped with isolators which basically are insulators that stop eddy currents from entering the bearing at the back of the motor. I'd be shocked is Tesla hasn't done something like this.

 

[gordo]

...The problem is, for whatever reason, there hasn't been much press coverage or word of mouth. I've spoken to a # of folks at my work who kinda want a Model S or like them and when I tell them about this, they don't believe me. I then forward them at least 1/2 dozen links of DU replacements due to noise, included repeated ones + the Edmunds long-term wrap up (2013 Tesla Model S Long-Term Wrap-Up | Edmunds.com)...

If those folks actually dug into these things...

As for "company would long ago have collapsed...", I stopped tracking long ago, but TSLA, when I stopped counting has accumulated over $1 billion in net losses.

Perhaps the reason there hasn't been more "word of mouth" is because:

1. Drive unit failures are largely relegated to specific batches (or perhaps the first xxxxx VINs out of Fremont).
2. Tesla replaces every failed/noisy drive unit under warranty for free.

I don't know whether assertion 1 is accurate, but neither do you. Only Tesla really knows and they're not speaking. So why spend so much of your time collecting forum posts and other anecdotes regarding a service problem for a car you don't even own?

Yes, I'm pointing out that your motives are suspect.

 

[yobigd20]

View attachment 87508

how do you get the car to stay attached hanging upside down like that??

 

[wycolo]

> I stopped tracking long ago, but TSLA, when I stopped counting has accumulated over $1 billion in net losses. [cwerdna]

How does a stock 'accumulate net losses'? Or do you mean Tesla, Inc? What exactly were you tracking?
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