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Clunks, Drones and Milling sounds: Just had a drive unit fail

Discussion in 'Model S' started by Erleichda, Nov 4, 2015.

  1. Erleichda

    Erleichda Member

    Joined:
    Jan 15, 2013
    Messages:
    69
    Location:
    Portland, OR
    Our 2013 P85 with 31k miles just had the drive unit fail. We had experienced the "clunk" when lifting off acceleration before regen started; our SC was contacted and a 'fix' employed that took care of it. We were not informed of what the fix was. The "droning" at speed >60 began to get more noticeable since but there was no milling sound, as demonstrated on TMC anyhow. The milling I listened to posted to Soundcloud really did sound sort of like cicadas in its variation, pitch and when it occured was not like our droning sound.

    Last night, wife driving home at 11pm and heard a thunk in the rear, then a clear drive unit fail. 1 hour for the flatbed but Tesla service knew on the phone right away what it was as did I.

    I spoke to the service center in PDX today (who happened to have a DU on hand) and asked a few questions:

    1. You have been replacing a lot of drive units, it seems like mostly for some abnormal sounds and not drive failures?
    A: Correct, failures are rare. We are being preventive in replacing them.

    1. Which sound is the one to worry about, when do we call them?
    A: (not clear) call anytime and will have a technician ride along and send any concerns to engineering.

    2. What changes are made to deal with the clunk, the drone or the milling? What revisions have been made?
    A: I don't know and we'd have to get an engineer to help us answer that question.
    2b: Can I?
    A: Um, well, not at this er...we will know more soon. We are a new company and constantly improving.

    3. Should I worry every 30k miles? How about after the warranty is up?
    A: We don't know and are a new company and constantly improving. You are under warranty for now.

    4. Is this a refurb DU and which revision is this, A-M?
    A: It is a refurb, and it is "version "P".

    5. If we were to trade in our car, should we get a dual motor or avoid a P?
    A: The duals are too new to know. We have been replacing both standard and Ps.

    6. Is this same DU revision in the Model X?
    A: We don't know at this time, as a service center we don't have all the specs. We will start seeing them soon and will then know but I expect they will be the same for the large DU.



    Overall, they are very nice about this but...they have been well coached in responses. They seem to be all over the DU replacement issue, so it must not be rare even if actual failures are. I think others on the forum have had great speculation about the sounds not coming from just one thing and that one? plus the failures are due to unexpected wear occurring in the differential/transaxle. It seems like the use and complexity of an induction motor instead of brushless is perhaps the reason for their success but also this issue. I can see this going one of two ways, and neither will we know up front. There is too much for them to lose to be transparent.

    1. Engineering fixable: They are on revision P...they are learning from each replacement and refining for long-life drive units. Their earlier efforts in cars with 3-4 replacements will become rare due to what they have learned and improvements made. They will be more and more transparent and explanatory about the issue.

    or

    2. More complicated than they can handle: These are the basis for all Model S and X, if not their business secret sauce on top of their battery. Thus they have to string everyone along as they grasp at straws and keep seeing issues providing as little information to owners/public as possible. This worries me in regards to their solvency and long-term plan. I'm concerned their actions sort of reflect crisis management?
     
  2. James Anders

    James Anders Member

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    Mar 13, 2014
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    744
    Location:
    Southampton, PA
    Would love to see the actual bearings used in a DU. Prior comments about electrical current causing premature bearing wear and failure are well known failure modes. Some bearing systems actually use liquid metal seals to conduct electricity and heat away from bearing. Years ago it would be mercury. Now it's often gallium/indium/tin alloys.
     
  3. brantse

    brantse Member

    Joined:
    May 18, 2015
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    398
    Location:
    Somerset, PA
    These DU issues are starting to drive me nuts. Does anyone have any idea how high the VIN's go until DU issues aren't really present? It appears that almost all of the DU replacements were 2012/2013 vehicles. Or is that just due to the fact that these vehicles will expectedly have the highest mileage.
     
  4. sickfox

    sickfox Member

    Joined:
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    386
    Location:
    San Francisco
    I just got my DU replaced. Picked up the car Dec. 2014. I put 30K miles then I started hearing the noise.

    There are multiple threads about the DU but from what I've gathered so far, it happens mostly to Performance models and 2012-2014 built. SC told me after they replaced my DU with a brand new and improved DU, whatever that means.

    My main concern is after the 8 year warranty has expired and this same issue happens again, how much will this cost me? Parts and Labor? I'm planning to keep my #PearlWhiteModelS for a loooong time.
     
  5. WarpedOne

    WarpedOne Supreme Premier

    Joined:
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    2,651
    Location:
    Slovenia, Europe
    It should mean it is a brand new and improved DU made to latest spec which has fixes to problems that bugged older spec'ed DUs.
    As opposed to rebuild older DU, that failed to some other owner and was sent back to mothership, pulled apart, studied and inspected, replaced failed and problematic components, reassembled and re-warranted as 'refurbished'.

    Assumption 1: brand new and improved DU will fail after 8 year warranty has expired
    Assumption 2: you will still own this same specimen
    Assumption 3: there won't be any alternative to replacing the whole DU
    Assumption 4: you will have to pay the full price of a new DU

    My crystal ball does allow inputting so many assumptions so I cannot help you there.
     
  6. brantse

    brantse Member

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    Somerset, PA
    I'm totally fine with them installing refurb'd DU's, providing one significant caveat - they know exactly what the failure mechanism was and they correct it. To date, I honestly don't think that's ever been accomplished. If it was, we wouldn't have to have this discussion.
     
  7. qwk

    qwk Model S P2681

    Joined:
    Dec 19, 2008
    Messages:
    2,817
    1. They know exactly what the problems are.
    2. A permanent fix costs real money, and the Tesla way is to try to find a cheaper fix, AKA "patch".
    3. They will end up spending multiples doing "patches", rather than fixing it right the first time.
     
  8. mknox

    mknox Well-Known Member

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    I agree with that. I've had one replaced in late October 2013, but don't know whether it was new or refurbished or what "version" it was:

    11-6-2015 10-19-46 AM.jpg

    I've been waiting for about a year now on another replacement, and was able to at least get them to note this on a Service Order in July of this year:

    11-6-2015 10-33-36 AM.jpg
     
  9. apacheguy

    apacheguy Sig 255, VIN 320

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    So Cal
    @mknox - From the part number it was new and a Rev. E.
     
  10. mknox

    mknox Well-Known Member

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    Thanks. The first one had the low "power transformer-like" drone, but absolutely no "clunk" between re-gen and acceleration. The current one has the "clunk" (which Tesla originally said was "normal") and now the ever louder "milling" sound.
     
  11. Lyon

    Lyon 2016 S P100DL, 2016 X P90D

    Joined:
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    Location:
    Eugene, Oregon
    My DU's been replaced twice (I'm on my third one) and this was the code from the last one, installed at the end go August 2015.


    ASY,P-TRAIN,RMN,MDLS,SPORT,CMC,HS
    (1025598-00-P)
     
  12. EMP40

    EMP40 Member

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    Location:
    Roseville, CA
    We keep our cars a long time. Would like to buy mid 2016 to replace 2002 Jeep Grand Cherokee but the lack of information on failure rates and replacement costs makes me nervous. If a refurb drive unit was only $2k it would be much less a concern.
     
  13. mknox

    mknox Well-Known Member

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    Well, the 85/90 models have 8-year, infinite mile warranty on the battery and drivetrain.
     
  14. Max*

    Max* Autopilot != Autonomous

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    All new cars Tesla sells have this (i.e. so do the 70s), only the 60s had less warranty (I forget, 8 year 100k mile? 125k mile?)
     
  15. DFibRL8R

    DFibRL8R Member

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    Location:
    Leesburg Virginia
    60 has been 8 years/125k miles. Recent 7.0 software update now has 8 years/unlimited miles on the warranty section of the on-screen manual. Hoping this is correct since I will hit 125k miles at only 6 years based on current driving. Seems like a 60 should put less wear on the drive unit given a lower power output and lower curb weight. I've got about 60k miles on my current DU (had the original replaced for intermittent failure at only 3k miles)
     

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