100% drive unit failure rate??

[Doug_G]

My car is coming up on three years old. I've had one drive unit replacement due to the milling noise, and another due to a sudden mechanical failure of the transaxle gearbox. The latter issue is rare, but nevertheless it's pretty clear that many older cars have had one or more drive unit replacements.

Tesla claims to have the reliability problems figured out, per Elon on the conference call. I've heard that the new small drive units are extremely reliable. I've also heard that the new large drive units have been improved to have the same reliability, and that they're doing the same upgrades to the rebuild units.

Hopefully they've put all this behind them... though there are probably quite a few older units still out there that will eventually need replacement.

 

[mknox]

I also stress the difference between DU failures and DU problems. There have been many people who have had problems with the DU leading to replacement by a service center, but there have been very few failures. A failure meaning you have been stuck someplace with the car non-operational and the problem was the DU.

Semantics. If my audio systems develops a seriously loud hum, but I can still hear the music playing, I consider that a "failure". If you replace "failure" above with "breakdown", then I would agree with you.

 

[Max*]

Lots of people have argued about the term "failure" when it comes to DU, I agree with mknox's definition.

It's not a critical failure that leaves you stranded, but it's a failure in the sense that it's not operating as intended. It could be a design failure too, since they keep patching it (rev Q, anyone?) but haven't fixed it yet (and I fully understand it's not an easy problem).

 

[ohmman]

Semantics. If my audio systems develops a seriously loud hum, but I can still hear the music playing, I consider that a "failure". If you replace "failure" above with "breakdown", then I would agree with you.

Of course if you use an audio delivery system as your example, the inability to deliver clear audio is a failure. That's an unfair analogy. I'd argue that if I had a portable radio shaped like a wheel, and while listening to it, it took off driving, I'd consider that a failure as well.

The drive unit is intended to propel the vehicle. It continues to do that.

I agree that these are semantics, and I definitely agree that this issue needs to be resolved (remember, I had a DU replaced for a quite loud milling noise as well), but I don't think we do anyone any favors by outright naming this a failure. It's unfair to those who have had real DU failures that left them stranded.

 

[mknox]

Of course if you use an audio delivery system as your example, the inability to deliver clear audio is a failure. That's an unfair analogy.

How has a drive unit that is supposed to propel the car "silently" not failed when it does so loudly enough that passengers question it and pedestrians on the sidewalk turn around and stare?

It's unfair to those who have had real DU failures that left them stranded.

I would call that a breakdown. "Breakdown" is a generally accepted term for when something happens to a car that leaves you stranded at the side of the road.

 

[islandbayy]

Of course if you use an audio delivery system as your example, the inability to deliver clear audio is a failure. That's an unfair analogy. I'd argue that if I had a portable radio shaped like a wheel, and while listening to it, it took off driving, I'd consider that a failure as well.

The drive unit is intended to propel the vehicle. It continues to do that.

I agree that these are semantics, and I definitely agree that this issue needs to be resolved (remember, I had a DU replaced for a quite loud milling noise as well), but I don't think we do anyone any favors by outright naming this a failure. It's unfair to those who have had real DU failures that left them stranded.

I disagree. I consider the milling, clunking, etc... as a Failure. Especially, since preferably, you want to fix/replace to Eliminate the problem BEFORE it becomes a full blown breakdown.


In a ICE Car... You have a transmission that is slipping like a SOB. By your definition, that would be working just fine, since it is still able to propel the vehicle and shift, just not perfectly or as quickly as it should. Yet, that is a Pending breakdown and complete failure. Again, would want to remedy the issue BEFORE it became a breakdown.


I've been stuck places at Zero degrees out with my two small children. If I have the opportunity, I will not allow a Pending Failure to become a full blown breakdown.

 

[Max*]

I disagree. I consider the milling, clunking, etc... as a Failure. Especially, since preferably, you want to fix/replace to Eliminate the problem BEFORE it becomes a full blown breakdown.

I agree that it's a failure, but I've heard lots of people say that the milling, clunking, etc. does not directly lead to a breakdown. Dunno how true it is though.

 

[WarpedOne]

So, a loose cable that is vibrating and beating against the chassis counts as DU failure?
Good to know...

P.S. By such a definition of failure there is not a single ICE engine out there that is not constantly in a failed state. Totally Irreparable.
Every ICE has bits that are wiggling a bit different than intended, causing noise.

 

[Krugerrand]

So, a loose cable that is vibrating and beating against the chassis counts as DU failure?

Good to know...

Yes. It's akin to being pregnant, you can't be 'kind of' pregnant. In this case there are people who believe the DU is either pregnant (working) or not pregnant (failed). It's black and white, no grey. (I know, right?)

 

[mknox]

So, a loose cable that is vibrating and beating against the chassis counts as DU failure?

No, that would be a failure of the mechanism that supports/attaches the power cable.

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I agree that it's a failure, but I've heard lots of people say that the milling, clunking, etc. does not directly lead to a breakdown. Dunno how true it is though.

My first DU failed with a very loud low frequency hum, but I did not suffer a breakdown. My current DU has the clunk and very loud milling noise (awaiting replacement) but I have not suffered a breakdown.

I'm not sure if I eventually would suffer a breakdown, but Tesla tells me I won't. They also told me that being on the proactive battery contactor replacement list wouldn't lead to a breakdown, but unfortunately it did. So who knows?

 

[JRP3]

We had a truck at work with an excessively noisy steering pump. It was never replaced and it never failed. A new one would have been quieter, but not silent, and other than the noise would have functioned the same. The Tesla drive train when brand new and functioning properly is not silent, it just makes a very low level of noise. At some level of noise it becomes unacceptable, but just making a noise is not a failure nor can you assume it will always lead to a failure.

 

[apacheguy]

Yeah I'm of the camp that noise != failure since it really complicates discussing these issues with non-Tesla drivers. Most don't understand the difference between having your drive unit swapped for milling, clunking, or outright failure.

 

[ohmman]

In a ICE Car... You have a transmission that is slipping like a SOB. By your definition, that would be working just fine, since it is still able to propel the vehicle and shift, just not perfectly or as quickly as it should. Yet, that is a Pending breakdown and complete failure. Again, would want to remedy the issue BEFORE it became a breakdown.

I never said it was "working just fine." I have always asserted that this is an issue that should be addressed by Tesla. In the case of your slipping transmission, I would argue that's a much more serious issue than a bearing noise in the drive unit, but still not yet a failure.

apacheguy points out one of my main concerns. If I knew nothing about Tesla, and someone told me they'd heard that almost all of their drive units were failing, I'd be picturing a lot of stranded people. If someone told me that they were having noise issues with their drive units, I'd have a completely different view.

It's a serious issue. It needs to be addressed, and I am very hopeful they're making progress on it. But again, my opinion is that the argument is not aided by classifying it as a failure.

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No, that would be a failure of the mechanism that supports/attaches the power cable.

OK, so can we say that the milling noise is a bearing failure? :smile:

 

[Max*]

Yeah I'm of the camp that noise != failure since it really complicates discussing these issues with non-Tesla drivers. Most don't understand the difference between having your drive unit swapped for milling, clunking, or outright failure.

But ICE drivers understand the inconvenience it causes a person to come to the SvC to get the DU fixed for a <insert your word here, I call it a failure> due to milling, clunking, etc.

It's semantics. It's a problem, we can all agree with that? It's not a catastrophic failure, we can all agree with that?
Beyond that, some may call it an inconvenience, a bad design, a failure, etc.


If Tesla spun it that the DU needs a tune-up every 15k miles, I bet it would be better for their overall image. Hey, the EV isn't as maintenance free as we advertised, it's still less maintenance than an ICE, we give you FREE maintenance on the DU for 8 years, but every 15k please make an appointment for a tune-up. I bet 95% of people would be satisfied with this, there would be less of the term "failure", etc. The other 5% would demand a perfect DU that would never make a noise, and never need service.

 

[Tupelo]

This is a silly discussion, IMO. "Failure" v. Breakdown", or whatever else we may choose to call it, misses the point entirely. My DU was replaced (for the increasing level of the milling noise) because Tesla found that it was "defective", either in materials or workmanship, because that's what my DU warranty covers, and is the legal standard for warranty service under the contract that Tesla must honor. When the service tech drove the car with me, after about 100 yards down the street, he just shook his head and said "not a sound it's supposed to make...", and scheduled a replacement. When a part stops working as intended during the warranty period requiring a repair or replacement, it's considered defective, and if anyone asks what the problem was with my DU that's what I tell them.

 

[mknox]

OK, so can we say that the milling noise is a bearing failure? :smile:

Sure. Absolutely, if that's what it is. We do tend to lump everything under the Drive Unit umbrella, but it is really a number of components: motor, inverter, reduction gear/differential. I guess it's because Tesla has been replacing them as a single assembly. (You wouldn't replace an ICE car's entire drive train to correct a transmission problem).

 

[ecarfan]

It's semantics. It's a problem, we can all agree with that? It's not a catastrophic failure, we can all agree with that?
Beyond that, some may call it an inconvenience, a bad design, a failure, etc.

Yes, it is a "problem", not a catastrophic failure as in "car won't move". And Tesla is gladly fixing it.
Semantics ("the branch of linguistics and logic concerned with meaning") does matter.

 

[AmpedRealtor]

Most of the stories I've seen of DU Problems are in early build cars. Many of those early build cars have had new DU replacements and still had problems. That points to something in the car itself that is causing DUs to have problems.

You are connecting the wrong dots. The majority of the DU issues are mechanical. There is nothing in the vehicle that would cause multiple DUs to fail mechanically. The problem is in the DU itself. My first DU developed hum noise after only 500 miles from delivery. The next one developed same noise at 8,000 miles. The next one developed faint milling noise along with hum at 18,000 miles. Each DU replacement lasted longer than the previous one, but still needed replacement. My last DU was installed in February of 2015 and has been going strong without any problems in almost 20,000 miles.

So no, this is not an issue unique to older builds and there is nothing inside the vehicle that would be causing the DU to fail. That's like saying my business partner's radio caused her Lexus transmission to break down. Hardly.

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So, a loose cable that is vibrating and beating against the chassis counts as DU failure?
Good to know...

Whose DU was ever replaced for the above reason? Elon said it a year ago, but based upon what we know today it sounds like he was engaging in misdirection or didn't have a clear idea of the full extent of the problems at the time he made that statement.

 

[stopcrazypp]

So no, this is not an issue unique to older builds and there is nothing inside the vehicle that would be causing the DU to fail.

Actually from discussion above, I don't think that can be ruled out, esp with certain cars that have much higher prevalence of DU replacement and with DUs lasting a shorter time each time. This can range from electrical issues (that lead to bearing degradation), or mechanical on the output shafts (not the DU itself).

 

[Cyberax]

It's semantics. It's a problem, we can all agree with that? It's not a catastrophic failure, we can all agree with that?
Beyond that, some may call it an inconvenience, a bad design, a failure, etc.

The problem is, it CAN become a catastrophic failure without any other warning. It happened to me - one day my car simply refused to drive and had to be towed for a DU replacement.

And since there's no way to distinguish between "benign failure" and "creeping catastrophic breakdown" scenarios, people have to treat milling sound as the second one.