Drive Unit failure symptoms and thresholds for replacement

[gavine]

So now I want lifetime watts/mile and mileage graphed against DU replacement. I think that will be very enlightening.

Lifetime watts/mile is not necessarily an indication of how the car was driven. Running the heater jacks that number way up.

 

[cwerdna]

Has Tesla ever had an NHTSA recall? Recalls are very common in the industry but not having one would have you presume that a lot of testing went into the Model S before coming to market.

Yes, but not for car losing power/coming to a stop unexpectedly while in motion. Click on Recalls when visiting http://www-odi.nhtsa.dot.gov/owners/SearchResults?prodType=V&searchType=PROD&targetCategory=A&searchCriteria.model=MODEL+S&stats=1839811%2C2%2C1%2C29%2C12%2CMODEL+S&makeStats=&jsonBaseURL=%2Fdownloads%2Ffolders%2F&searchCriteria.model_yr=2013&searchCriteria.make=TESLA&searchCriteria.prod_ids=1839811. You can lookup recalls for any car at Home | Safercar -- National Highway Traffic Safety Administration (NHTSA).

As for the above symptom, it would help if drivers who experience legitimate safety defects (not user error: e.g. running out of battery) report them to both their automaker AND NHTSA (or appropriate counterpart for their country). I've encouraged people to do so (even on other makes and models where I'm a fan/enthusiast of) and even had some of that got carved out into another thread: When to report NHTSA issues?.

Unfortunately, there are a vocal few who believe that it's "best" to not report them to NHTSA for whatever reason (e.g. "protecting" Tesla, car coming to a stop while in motion "isn't" a "safety "defect" despite tens of millions of other cars having been recalled for "stalling", "losing power", turning off unexpectedly, etc. and that continue to do so, etc.) and discourage others from doing so by making by making such arguments.

It even says to report them to both in the manual (I quoted it at When to report NHTSA issues? - Page 8).

I currently have no more time nor motivation to argue w/people who won't change their mind. At least some here agree with me and I've observed a few here have seen the light. On other car forums I'm on, there is NOT the same backlash about reporting clear safety defects to NHTSA and others there frequently call for reporting them, if the driver legitimately encountered them, preferably after reasonable attempts have been made to resolve the issue, when possible.

Again, I'm not calling for a recall, merely for reporting legitimate safety defects. It might spur more action on this issue on both Tesla's side or NHTSA's side (which might push Tesla). They both can then make the determination whether a deeper investigation or recall is warranted. But... if reports don't make to NHTSA and there are some inside Tesla who have the same "belief" that the above symptom "isn't a safety defect"...

Re: the testing on Tesla's side, I do really wonder. Setting aside total drive unit failure, there's still the issue of HV battery pack replacement due to something inside failing (contactor?) and the drive unit noise issues. It seems to me, if you bought a Model S between its 1st day on the market and now, the chances of requiring at least 1 drive unit replacement before 100K miles is pretty high, given the noise problem still keeps happening and some folks have been thru multiple replacements for noise.

I posted some stuff on durability testing at other automakers at My Nissan Leaf Forum View topic - Official Tesla Model S thread and My Nissan Leaf Forum View topic - automotive reliability and durability testing. And, got a response at My Nissan Leaf Forum View topic - Official Tesla Model S thread. And, keep in mind the Nissan, GM, Chrysler and Ford are not exactly top tier in terms of overall reliability across all their vehicles, year over year (i.e. not up to Toyota/Honda standards).

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^^ this. Granted, we aren't seeing many of the early problems - door handles not working, doors opening randomly, cars leaking, alcantara/headliner issues, pano roof issues, etc. But the drive unit and 12v battery issues seem to persist. Now the P85D w/ air suspension has a shock "design issue" that is causing the shocks to make a sound when going over bumps. Tesla is in the process of "redesigning" the shocks and will issue a service bulletin for affected vehicles. Another example of not properly testing something, waiting for owners to have problems, then send back to engineering for a redesign.

THAT'S NOT HOW YOU DESIGN A CAR! That's how you piss off owners and show the world that you have low initial quality.
...

I appreciate that Tesla decided that it needs to iterate quickly as an automotive startup, but doesn't that come at the owner's expense? Regardless of the service experience, it's still an inconvenience when the car throws an error, you must take the time to call service for diagnosis, then drive the car into service if it's more than 10 miles from the service center, etc.
...

Most automobile companies field test their vehicles in all sorts of extreme conditions before committing to production. They test the car in conditions ranging from bitter, cold winter weather to scorching, hot desert summers. I've yet to hear one example of Tesla doing this with any of their cars. In 2012 and 2013 we had reports of side view mirror components corroding due to salt exposure. The same issues affected structural beams in the frunk. All required service bulletins and an iterative fix in manufacturing. This doesn't happen if you properly field test your cars in the first place. Those problems will express themselves during testing, and a traditional car company would solve those problems before putting the model on sale. Tesla appears to do none of this.

Agreed. Re: cold weather testing, Tesla posted Cold Weather Climate Testing the Model S | Tesla Motors.

Re: scorching summer testing, all/virtually all automakers selling in the US conduct tests in Death Valley: Death Valley's a hotbed of car-testing intrigue - ABC News and Vehicle Testing - Death Valley National Park (U.S. National Park Service).

But yes, when one sees multiple people going thru multiple drive units (not just you) but these: 2013 Tesla Model S Long-Term Wrap-Up | Edmunds.com and Model S Not Ready For Commercial Use Prime Time. Can I afford to own this car?, one does wonder about the long-term durability and reliability testing along w/manufacturing consistency. Let's say Tesla passes their own (theoretically tough) durability tests w/flying colors, how consistently can they and their suppliers deliver that same level of quality and what quality checks are in place to ensure that keeps happening?

 

[ke6jph]

I find this thread interesting...as a service tech for GM and doing fleet repair covering most other brands, I deal with concerns like this almost every day. You should see my email. Software updates, hold orders, updated parts, engineering requesting data,pictures, old parts........ I understand the frustration of the owners on this thread and of my customers at work. It is difficult to tell a consumer that his/her car is operating as designed (while there is no fix at this time), or that the part provided to fix the issue did not, ect... I am just as frustrated as you and I do not even own a Tesla (yet ). I do feel that this and other issues will be resolved. As previously stated all cars have issues. The more tech on a moving car, the more chances of issues. I can tell you that I back up my faith with my wallet. I am all in with Tesla. After working in this industry for over 35 years it is time for a change. My retirement account is growing as is my confidence that Tesla will make every effort to not only permanently fix the drivetrain issues, but hopefully satisfy the doubts that some of you have in this regard.

 

[David99]

... the chances of requiring at least 1 drive unit replacement before 100K miles is pretty high, given the noise problem still keeps happening and some folks have been thru multiple replacements for noise.

It's too simple to call a drive unit replacement a major issue. Drive unit, in terms of an ICE, is a huge deal and a major part. In case of the Model S it is just much simpler to replace the entire unit, which is relatively small and easy to replace as a unit. It would be much more work for a service to take it apart. So when they replace it, it doesn't mean the entire unit has gone bad.

The next thing that is confusing is the noise issue. On a typical ICE drive unit any kind of noise is an indication of a mechanical problem that causes more wear and can cause a catastrophic failure. In case of the Model S drive unit, it's a electric motor (which is a very very simple part) and the inverter which is pretty much an electric "amplifier". The buzzing noise and the balloon squeal is similar to the hum of a transformer. It's 'cosmetic'. It is not a mechanical problem that, when not taken care of, causes more mechanical issues. It's not like a lose gear that will eventually break out and destroy the entire transmission.

The confusing part is really the term 'drive unit' as it suggests the heart and soul of the car as gone bad and needs to be replace. That's definitely not the case with the vast majority of reports here. The heart and soul of the Model S is the battery and it appears to perform amazingly well. The battery on an EV is the make or break part. Electric motors and power electronics are simple and cheap. Tesla has done a phenomenal job on creating a battery that withstands the daily use and abuse in any climate and accelerating a really heavy car like a sports car.

The 12 Volt battery issue is very unfortunate. Tesla dropped the ball on double checking the quality on those. They got a bad batch, let it slip and it unfortunately forces the entire car to shut down. It's a great example how a small part can bring a whole system down, even when all other parts are top quality and 100% reliable. Again, yes Tesla needs to up their quality control, but it's not a fundamental issue and an easy fix to owners.

I totally agree, there are many little things that quality control should have caught, but how much is an EV worth that has none of the small issues but the same battery as the Leaf that we all know ages at a rather scary rate?

 

[Amped-Up]

I just had the MS in for one year service at 15k miles. SC replaced the DU ("proactive replacement") with a rebuilt unit. I was getting a clunk in stop and go driving. Now there's a buzzing/whine on acceleration that goes away as speed increases. That's new and I'm keeping an ear on it. Still my '05 MBE500 4matic, bought new, blew the transfer case at 38K miles -a $6k repair if it wasn't still under warranty. Of course it did it again at 108K mi, just after my extended warranty ran out. My vocal unhappiness at least got the dealer to pick up parts but I paid over $3k for labor...So as far as I'm concerned - Tesla still has a ways to go to beat that sorry record...

 

[cwerdna]

It's too simple to call a drive unit replacement a major issue. Drive unit, in terms of an ICE, is a huge deal and a major part. In case of the Model S it is just much simpler to replace the entire unit, which is relatively small and easy to replace as a unit. It would be much more work for a service to take it apart. So when they replace it, it doesn't mean the entire unit has gone bad.

Ok. So, what happens when someone is out of warranty?

The next thing that is confusing is the noise issue. On a typical ICE drive unit any kind of noise is an indication of a mechanical problem that causes more wear and can cause a catastrophic failure. In case of the Model S drive unit, it's a electric motor (which is a very very simple part) and the inverter which is pretty much an electric "amplifier". The buzzing noise and the balloon squeal is similar to the hum of a transformer. It's 'cosmetic'. It is not a mechanical problem that, when not taken care of, causes more mechanical issues. It's not like a lose gear that will eventually break out and destroy the entire transmission.

You're mixing two or more issues together. The balloon squeal noise is from the contactors. Tesla states that's normal: Model S Technical / Mechanical Issues - Page 230.

There are definitely multiple different symptoms of drive unit noise (and likely different causes), for which Tesla has either replaced the DU or done other work to remedy. I don't have time to point to all the recordings here but here are Edmunds:
Ominous Noise - 2013 Tesla Model S Long-Term Road Test

Replacement: Ominous Noise Fixed - 2013 Tesla Model S Long-Term Road Test

I've definitely heard others that are different.

Edmunds unfortunately didn't post recordings of the milling noise (Tesla's term) at Drive Unit IV: The Milling - 2013 Tesla Model S Long-Term Road Test.

Drive unit problems explanation by Elon - Page 5 enumerated some symptoms.

Drive unit problems explanation by Elon - Page 9 mentioned gearbox.

 

[supratachophobia]

But did it fail within the life of ownership; be that 1yr, 3yrs, 8yrs, etc.

Without a warranty, the car would be next to worthless 2nd hand.

 

[MarkR]

This is why I will never, ever, buy a Tesla product unless it's been market-tested for at least 2 years.

Tesla has a really bad habit of using its owners as beta testers and offloading QC that should have been done by Tesla onto its customers. The reason Tesla service is so superior is because Tesla knew, very early on, that it will have to mitigate poor initial quality by offering a great service experience.

Ca'mon Sonny. As early adopters, you and I expected that everything would not work perfectly. It is my impression that TM is working hard to minimize service issues. The MS is a cutting edge vehicle whose owners will occasionally experience frustrations associated with new technology. TM could spend more time testing each new innovation, the P85D could have been tested for another year prior to delivery, and the Model X could be delivered in mid 2016, but the customer base would not be happy. I'd rather be part of the feedback loop that will speed the development cycle than wait for more lengthy Beta testing.

I can respect your desire to wait for the bugs to be worked out. It's easy. Wait for a new model to be introduced and then wait for two years to insure that the bugs are removed. I'm not sure how you'll handle software updates that might have errors - wait another two years?

 

[kennybobby]

It's too simple to call a drive unit replacement a major issue. Drive unit, in terms of an ICE, is a huge deal and a major part. In case of the Model S it is just much simpler to replace the entire unit, which is relatively small and easy to replace as a unit. It would be much more work for a service to take it apart. So when they replace it, it doesn't mean the entire unit has gone bad.

The next thing that is confusing is the noise issue. On a typical ICE drive unit any kind of noise is an indication of a mechanical problem that causes more wear and can cause a catastrophic failure. In case of the Model S drive unit, it's a electric motor (which is a very very simple part) and the inverter which is pretty much an electric "amplifier". The buzzing noise and the balloon squeal is similar to the hum of a transformer. It's 'cosmetic'. It is not a mechanical problem that, when not taken care of, causes more mechanical issues. It's not like a lose gear that will eventually break out and destroy the entire transmission.
....

Did you forget about the gearbox, located between the motor and the inverter? It is a major part of the drive unit also and has bearings and gears and provides the differential function for the axle shafts--those are not electrical parts, but are very, very simple mechanical components.

The milling or whine or clunking sounds are just different stages as the bearings wear and open up their internal clearance, likely due to axial loads. The next sound after the clunk would be whatever noise a failed gearbox makes--probably like a transmission that you indicated.

It's not trivial to make a single speed gearbox with differential capable to handle very large torques.

 

[supratachophobia]

Ca'mon Sonny. As early adopters, you and I expected that everything would not work perfectly. It is my impression that TM is working hard to minimize service issues. The MS is a cutting edge vehicle whose owners will occasionally experience frustrations associated with new technology. TM could spend more time testing each new innovation, the P85D could have been tested for another year prior to delivery, and the Model X could be delivered in mid 2016, but the customer base would not be happy. I'd rather be part of the feedback loop that will speed the development cycle than wait for more lengthy Beta testing.

I can respect your desire to wait for the bugs to be worked out. It's easy. Wait for a new model to be introduced and then wait for two years to insure that the bugs are removed. I'm not sure how you'll handle software updates that might have errors - wait another two years?

See, this is another one of my favorite arguments around here. Believe me, I know we all volunteered to be lab-rats driving around 4-wheel iPads. What's more, those first 10k owners were the REALLY crazy ones. Hell, the first 500 should have gotten their own Insane mode button.

But the facts stand, 3rd production year, six figure price tag, service visits every single month for issues that the 1st production year had, plus new ones. At this point, the quality is unreasonable to overlook. They don't get a pass on this, they cant get a pass on this. And if you keep taking the early adopter argument, you are doing a disservice to every single owner that comes after you.

It isn't difficult to come out and say, "Hey, as part of regular warrantied maintenance, if you hear these sounds or feel this vibration, we need to do this, this, and this". Cut the crap of having the owner decide what is and is not normal, most of us don't have time for that anyway.

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Lifetime watts/mile is not necessarily an indication of how the car was driven. Running the heater jacks that number way up.

Very true, although watts/mile sans HVAC is probably deadly accurate to predict drive-unit stress.

And if they can somehow take into account watts devoted to HVAC (they can, and I'll bet you lunch they do), the resulting adjusted number with the corresponding mileage is going to be spot-on when graphed with drive-unit replacement.

Here, in the drive-unit replacement poll, is there a graph with mileage at replacement, avg watts/mile, and location of owner (to estimate HVAC usage very roughly)? I know that wont give us 100% accuracy, but I think there would be a trend that we would find interesting.

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Unfortunately, there are a vocal few who believe that it's "best" to not report them to NHTSA for whatever reason (e.g. "protecting" Tesla, car coming to a stop while in motion "isn't" a "safety "defect" despite tens of millions of other cars having been recalled for "stalling", "losing power", turning off unexpectedly, etc. and that continue to do so, etc.) and discourage others from doing so by making by making such arguments.

It even says to report them to both in the manual (I quoted it at When to report NHTSA issues? - Page 8).

I currently have no more time nor motivation to argue w/people who won't change their mind. At least some here agree with me and I've observed a few here have seen the light. On other car forums I'm on, there is NOT the same backlash about reporting clear safety defects to NHTSA and others there frequently call for reporting them, if the driver legitimately encountered them, preferably after reasonable attempts have been made to resolve the issue, when possible.

Yeah, you and I both got raked over the coals by the fanbois when I mentioned that it was a very serious issue to have the P85D with creep mode on and in reverse, not stop immediately when you pressed on the brakes. Granted, it was only in that state for 48-72 hours, but at least one guy lost some landscaping due to the issue. Thankfully no one lost a bike or a kid.

These things need to be aired and they need to be discussed.

 

[Scotty]

My MS is in Fremont, getting the DU replaced. It suddenly developed a very loud whining noise, that would get higher in frequency as the speed increased. At driveway speeds, it drew stares. Clearly, deer and pedestrians did not have to be worried that I might sneak up on them. The funny thing was I had 1070 KNX in LA on the AM radio, when I was down in the LA area. When I got into the central valley, I accidentally selected this station frequency, and WOW, I put the windows down, cranked up the sound, and short of the shifting common to ICE transmissions, it was the closest to a big block V* sound coming from my Tesla. Clearly, it's an electrical problem, which I suspect is the inverter. Remembering that a 3 phase AC induction controller incorporates 3 separate driver sections to drive each phase independently, as well as varying frequency and amplitude. I would love to get my hands on one... Their inverter (motor controller) as shown on Youtube newer factory tour shows, it's quite something. I remember a few years ago of a Electric Vehicle enthusiast who designed his own 3 phase AC induction controller (I think it was a newer VW), and it was very impressive. Last I saw, he blogged that he was switching jobs, and that Tesla hired him.

Clunking, Whining, Grinding is generally the complaints. What are you experiencing?

 

[gavine]

Very true, although watts/mile sans HVAC is probably deadly accurate to predict drive-unit stress.

Not sure I agree with this still. How about drivers who set their regen at low or don't use regen as much (late braking)? Also, how about drivers who go from reverse to drive when backing out of the driveway without stopping completely. That has to put heavy strain on the bearings and gears. If you do that every day but have a low WH/mile number, you're going to still have wear without the number reflecting it. I always stop completely before changing directions. I would argue that Tesla should use the hill-hold system to stop the car before allowing the direction change....allow the roll-back in reverse and neutral but brake as soon as "drive" is selected.

 

[wycolo]

> The milling or whine or clunking sounds are just different stages as the bearings wear and open up their internal clearance, likely due to axial loads. [kennybobby]

The milling sound ceases instantly as you cross the power/regen point using the accelerator. This points to an inverter source not mechanical. I rather like mine - sort of a space ship sound.
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[kennybobby]

> The milling or whine or clunking sounds are just different stages as the bearings wear and open up their internal clearance, likely due to axial loads. [kennybobby]

The milling sound ceases instantly as you cross the power/regen point using the accelerator. This points to an inverter source not mechanical. I rather like mine - sort of a space ship sound.
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Or it could be the reversal of axial load as the torque goes from the motor driving the gears, to the gears being back-driven by the wheels. The inverter is still working all the time in a 4-quadrant controller.

 

[supratachophobia]

Not sure I agree with this still. How about drivers who set their regen at low or don't use regen as much (late braking)? Also, how about drivers who go from reverse to drive when backing out of the driveway without stopping completely. That has to put heavy strain on the bearings and gears. If you do that every day but have a low WH/mile number, you're going to still have wear without the number reflecting it. I always stop completely before changing directions. I would argue that Tesla should use the hill-hold system to stop the car before allowing the direction change....allow the roll-back in reverse and neutral but brake as soon as "drive" is selected.

Ehhh, I see what you are saying and it's got merits of a good argument. Buy you haven't convinced me that it could be stressed *that* much under the conditions you described..... Yet.

 

[Cal1]

Mine was replaced for gear slap. My symptoms were fairly obvious, slight clunk upon slow acceleration or abrupt coast. Tech did the recording for engineering verifying gear slap. The teeth of the gear unit had enough slop that you could hear around town in normal driving. Usually didn't hear anything on hard acceleration. They replace everything as a single unit, pretty sure refurbished mother and transmission but no way to verify. I don't care as long as they are covered by the 8 yr warranty AND it doesn't go bad again.

After about two weeks I have another drive sound clunk but different from the first. Tech did the recording for engineering again. Not sure what is wrong now. The wife feels the whine is louder than before but I'm pretty deaf so I can't tell.

Does this help with some of the symptoms causing replacement?

Cal

 

[AmpedRealtor]

So now I want lifetime watts/mile and mileage graphed against DU replacement. I think that will be very enlightening.

My first DU replacement was within the first 500 miles driven. The 2nd replacement for the same problem took place at approximately 8,500 miles. The third replacement was done again for the same issue at approximately 18,000 miles. I drive conservatively, I never "punch it".

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Ca'mon Sonny. As early adopters, you and I expected that everything would not work perfectly. It is my impression that TM is working hard to minimize service issues. The MS is a cutting edge vehicle whose owners will occasionally experience frustrations associated with new technology. TM could spend more time testing each new innovation, the P85D could have been tested for another year prior to delivery, and the Model X could be delivered in mid 2016, but the customer base would not be happy. I'd rather be part of the feedback loop that will speed the development cycle than wait for more lengthy Beta testing.

I can respect your desire to wait for the bugs to be worked out. It's easy. Wait for a new model to be introduced and then wait for two years to insure that the bugs are removed. I'm not sure how you'll handle software updates that might have errors - wait another two years?

When I bought the car, yes, I understood that I would be an early adopter and that I would be helping Tesla work out some issues. It was actually exciting for me to be part of this process of "changing the world" and helping Tesla succeed. What did I expect to happen? I'm not entirely sure. Early in my ownership experience I had some problems with pano roof seals, bubbles in my alcantara, trunk liner defects, etc. Those were fit and finish issues that I expected, and I didn't mind those at all. But the multiple drive unit replacements have left me with a nagging worry in the back of my mind. The battery and drive unit, I felt, were at the heart of Tesla's core competencies and I honestly was not anticipating having issues with those components. So far the battery has been great and no issues. The only recurring problem has been with the DU and the worry I have about it failing or developing a noise after the warranty has expired.

All of my other issues are fixed 100%. But the DU thing has been an ongoing thing for Tesla over the last 2 years and it keeps happening to me. I'm knocking on wood right now that my last (third) DU replacement was the charm, but I'd be lying if I said I wasn't worried about the long term. At least with the DU aspect, this isn't something I was expecting as an early adopter. I deal with the problem graciously at service and am thankful that Tesla is so quick to swap the part and get me out the door quickly. But the nagging in the back of my mind is still there and I don't know what to do with it.

 

[supratachophobia]

My first DU replacement was within the first 500 miles driven. The 2nd replacement for the same problem took place at approximately 8,500 miles. The third replacement was done again for the same issue at approximately 18,000 miles. I drive conservatively, I never "punch it".

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When I bought the car, yes, I understood that I would be an early adopter and that I would be helping Tesla work out some issues. It was actually exciting for me to be part of this process of "changing the world" and helping Tesla succeed. What did I expect to happen? I'm not entirely sure. Early in my ownership experience I had some problems with pano roof seals, bubbles in my alcantara, trunk liner defects, etc. Those were fit and finish issues that I expected, and I didn't mind those at all. But the multiple drive unit replacements have left me with a nagging worry in the back of my mind. The battery and drive unit, I felt, were at the heart of Tesla's core competencies and I honestly was not anticipating having issues with those components. So far the battery has been great and no issues. The only recurring problem has been with the DU and the worry I have about it failing or developing a noise after the warranty has expired.

All of my other issues are fixed 100%. But the DU thing has been an ongoing thing for Tesla over the last 2 years and it keeps happening to me. I'm knocking on wood right now that my last (third) DU replacement was the charm, but I'd be lying if I said I wasn't worried about the long term. At least with the DU aspect, this isn't something I was expecting as an early adopter. I deal with the problem graciously at service and am thankful that Tesla is so quick to swap the part and get me out the door quickly. But the nagging in the back of my mind is still there and I don't know what to do with it.

This is EXACTLY what I'm starting to find hard to push away now, that nagging feeling in the back of my mind. Yes, I understood there would be issues and compromises to make, but the quantity and variability of problems seem to be mounding up. The possible DU issue is just a bale of straw on the camel now.

The extended warranty for me is now a must if there is to be any hope in keeping this car on the road. Have you come to the same conclusion or is your ownership timeline a known quantity? I did come up with a theory that DU failure may be eliminated or drastically stretched out in the AWD models since the stress is split between two components. If/when you/I/we trade up, there could be that to look forward to.

 

[pgiralt]

My biggest concern is that the same issues keep coming back, so I'm concerned that Tesla still does not know the root cause of the problems or does not plan on addressing them in the current generation.

Here are my replacements:

06-Jan-2014 - 8079 Miles - ASY,P-TRAIN,MECH,COMPLETE,RC,REMAN,MDL S (1025276-00-F)
06-Aug-2014 - 23449 Miles - ASY,P-TRAIN,MECH,COMPLETE,RC,REMAN,MDL S (1025276-00-A)
08-Oct-2014 - 29913 Miles - ASY,P-TRAIN,MECH,COMPLETE,RC,REMAN,MDL S (1025276-00-A)
20-Mar-2015 - 42931 Miles - DRIVE UNIT - BASE WITH SHIMS - REMANUFACTURED (1025276-00-K)

I'm up to almost 45,000 miles and already the latest replacement is starting to hum above 70 mph.

The first replacement was for the humming above 60 mph. Second was for the buzzing at low RPM. Third was for humming again (this time it was above 70 mph). Fourth was for buzzing again. Now fifth will be for humming again over 70 mph. In each case, (except for the 3rd replacement), the drive unit was perfectly silent as expected after getting the drive unit replaced. The longest I've had a drive unit before needing a replacement is 15k miles. As far as threshold for replacement, there have been a few times for the above replacements where I reported the issue but the technician didn't hear it when the car was in for service but it would inevitably get worse to the point where they agreed to replace it.

Clearly there have been different revisions. I'm not sure why my first replacement was a -F and then there were two -A's followed by a -K. Clearly Tesla is doing something to try to fix things. Unfortunately the same issues just keep returning.

FWIW, I've never had the "clunk" issue that the shims were supposed to address. I don't drive particularly aggressively. Sure, I will floor it every once in a while, but that's rare. My lifetime wh/m is around 330 and that's mostly because of winter. My summertime average is around 309 wh/m.

 

[brianman]

I have not heard of a drive unit fail on any Model S owner yet. .... The drive unit problems discussed widely are all non-critical and the service will fix them. Elon even later added the drive unit to the full warranty.

Yes. David is correct.

Incorrect. The second drive unit on my Sig P85 became undrivable; the vehicle refused to go back into gear from park after a "safely" message followed by immediate deceleration to a stop. Tesla flatbed towed it back to the service center to be replaced. I know I'm not the first to report it on TMC.