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Drive Unit Problem / Fixes

Discussion in 'Model S: Driving Dynamics' started by nwdiver, Jun 22, 2014.

?

Drive Unit Replacement & Reasons

  1. ZERO (NO ISSUES)

    70 vote(s)
    47.0%
  2. ZERO (There's some noise but I can live w/ it)

    19 vote(s)
    12.8%
  3. 1 Due to Noise

    30 vote(s)
    20.1%
  4. 1 Due to Failure

    13 vote(s)
    8.7%
  5. Multiple Repairs due to Noise

    16 vote(s)
    10.7%
  6. Multiple Repairs due to Failure

    1 vote(s)
    0.7%
  1. nwdiver

    nwdiver Active Member

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    #1 nwdiver, Jun 22, 2014
    Last edited: Jun 22, 2014
    Ok... at the risk of creating a redundant thread... I'd like to see how common this is and how many people think it's a problem. I took my P85 in for service and got a 60 loaner. Very quickly I noticed how quiet the 60 was compared to my P85... it was dead silent. It seems that a large percentage of drive unit replacements aren't "necessary" but driven by MS owners wanting that ZERO sound driving back... Personally so long as my performance doesn't suffer and my car doesn't get louder than an ICE I'm ok with a little noise...
     
  2. ZBB

    ZBB Emperor

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    I'm not going to answer the poll, since my situation doesn't really apply.

    I had the drive unit replaced at ~12.5k miles. I personally didn't notice noise, but the SC manager drove the car with me to verify my alignment concerns and he immediately noticed that the drive unit was noisy. Only after he pointed it out did I notice it. So mine was replaced for noise, but not due to me complaining.

    Since it was replaced, not only is the car noticeably quieter, but I'm also getting lower Wh/mi readings on the dash. Prior to the replacement, I was averaging ~297 Wh/mi, and in the almost 4 months since I'm averaging 284. I think a little of that is seasonality since the 297 included an AZ summer, but my lowest month on the old drive unit was 294 just before having it replaced -- so I'll only give the new drive unit credit for 10 Wh/mi -- which is about 3% more efficient. I'm pretty happy about that and do believe the noise is an indication of an issue with the drive unit -- perhaps not an indication of future failure, but perhaps of a misalignment within it causing it to be out of balance and therefore less efficient and make a hum.
     
  3. Alysashley79

    Alysashley79 Member

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    I had mine replaced for failure. It made a "clunk" between regen accel and low speeds. However at any other time it was silent. This drive unit I have now. Make a lot of noise. However it's still quiet, just different noise than my other unit made. I had a service tech ride along with me and he said that the newer performance units are louder than the 60's (which I had just driven for two days) and the unit was three months newer than what my car as at the time they put it on. It as brand new not a refurb'd drive unit. So to the OP I don't know if you are hearing more noise because it IS a complete different unit. The 60 and 85 use the same drive inverter but the performance models are completely different!
     
  4. nwdiver

    nwdiver Active Member

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    Well.... this poll is FAR more encouraging than the last one :biggrin:
     
  5. Jhall118

    Jhall118 Member

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    Hey, I am also located in Seattle, and I had my inverter replaced (refurbished) for what sounds like the exact same issue! A clunk between regen and accel. After a thousand miles or so (a month) it came back. I just recently had my car returned to me, and the technician basically "torqued everything to spec" (that's what my invoice says). Well, 24 hours later, and it's starting to make the clunk again. Very annoying.

    If I picked you up, could you see if my car is making the same kind of clunk as yours was? I am worried that the service center is going to tell me it's normal, but it is NOT okay with me.
     
  6. AmpedRealtor

    AmpedRealtor Active Member

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    A clunking noise is not normal under any circumstances. If your SC tells you it's normal, tell them no it isn't. It will eventually lead to a drive unit or battery replacement.
     
  7. Jhall118

    Jhall118 Member

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    Thank you. The tech that rode with me said something about "gear slack" in the inverter and it being a normal sound. I will be insistent until it gets fixed!

    I totally believe in Tesla and will patient with them.
     
  8. jayhawk

    jayhawk Member

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    Location:
    Chicago
    I sometimes get a 'clunk' when I first put the car in gear and touch the accelerator. Had one drive train replaced, and now a loud noise around 40 MPH if accelerating quickly (along with screen message saying to take in for service). I will find out if I get a 2nd replacement on Wednesday. Before the first one, my car shut down while going 75 MPH on the highway. Gave me a warning to pull off and reset car, so I had to get over 5 lanes of traffic without any power (other than steering / breaking). Once I pulled over and turned the car on / off, everything was back to normal, but it was not fun having everything shut down while on the highway.
     
  9. petero

    petero Member

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    May 22, 2012
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    No drive unit problem. Most of the comments for noise and replacement have been from P85 owners and a few from S85 owners. Do the S60 have this same kind of drive unit problems too?

    For the record when my S60 was in for 12K servicing I had a P85 loaner and I found it much noiser (and far quicker). I also found the 21" wheels and tires may help the handling big time but do not enhance the smooth, quiet ride.
     
  10. paco3791

    paco3791 TMC OG

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    Antioch, IL
    Yes my S60 inverter was replaced due to noise. My understanding was that my noise issue was a bearing wear issue, not sure that covers all of the issues labeled as "noise". Also as a side note I don't believe there are any physical differences between the non performance 85 and 60 drive units. Based on my experience there must be some firmware changes from the factory between the two but that is the only difference between them, so any problems we see with standard 85 drive units should be more broadly applicable to the 60 population.
     
  11. MTOman

    MTOman Member

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    When I was at the SC a few months ago for a tire rotation (~ 4k miles) I asked about the "thunk" I was hearing between regen and acceleration and was told it's normal, but I could swear I didn't remember it doing that when I first got it. So I did some research, asked other MS owners if they had a thunk, and the unanimous opinion is that it shouldn't exist, it should be completely silent between regen and accel.

    The noise got a little annoying in stop-and-go traffic, and you could feel the thunk in addition to hearing it, so it became a challenge letting off the accelerator just right so that it didn't thunk. I called the SC about it a couple weeks ago (~ 9k miles) so they picked it up yesterday and let me know today they identified something in the drive unit and are in the process of replacing it. They are also installing updated motor mounts, does anybody have any info on what's changed with these? Should have it back tomorrow, we'll see if that does the trick!
     
  12. MTOman

    MTOman Member

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    Update - just got my car back a little while ago and now it's smooth as butter! No clunk between accel and regen and it doesn't even make those whining noises when you floor it, totally silent no matter what you're doing with the accelerator. Even when my car was brand new it made those electrical whining noises when you floored it, not anymore. I'm very impressed!!

    On a side note, I noticed the paperwork says they replaced the drive unit with a new one. I asked when they were dropping it off if that means new-new or refurbished-new, he said new-new and that they don't install refurb'd drive units.

    I was also impressed at all the other things they did while it was in, things I didn't even know to ask for. For example, they found in the log files that the powertrain pump had faulted multiple times in the past month so they went ahead and replaced it with a new pump. They also "checked and trimmed both rear arch liners", not sure what those are yet but glad they trimmed them :) Also mentioned in the work order was installing an updated motor mount. I've read speculation in other threads that the noise problems developing in some of the drive units are a result of the motor mounts, so I'm crossing my fingers this fixes the problem permanently! I also requested they install the titanium underbody shield which they did.

    Overall it was a fantastic service experience, I even got to drive a S60 loaner for a couple days (what a difference!) and my car came back all clean and shiny. While some may argue that a DU problem in less than 10k miles is unacceptable, I feel that if the customer is taken well care of and not inconvenienced by the problem then it's no big deal, stuff happens! I was never left stranded as the problem was only a noise and the service experience was amazing and no inconvenience whatsoever.
     
  13. AmpedUP

    AmpedUP EV Nut

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    MTOman....I'm pleased to hear you describe this drive unit replacement as seeming better than new. I don't think I've read a similar description from others after a drive unit replacement. Perhaps you are one of the first to receive a unit with a new design? If so, the timing couldn't be better, what with all the Tesla shorters sniffing around this issue.
     
  14. AmpedRealtor

    AmpedRealtor Active Member

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    My car was delivered in August of last year. It had the highway hum from day one. The first drive unit replacement at 500 miles was much quieter at highway speeds, but offered a strange, wooshing UFO sound between 30-40 MPH. The only way I can describe it is the sound the Enterprise makes when its warp engines are spooling up. That drive unit lasted 8,000 miles before the highway hum returned, coincidentally right after my tires were rotated. Service confirmed it was the drive unit because the noise disappeared when no power went to the motor, so not tire noise. I've driven 3,000 miles on my 2nd replacement (3rd drive unit if you count the one from the factory) and so far it is the best and quietest of the bunch. No strange noises at all, no hum at highway speeds. But it's only been 3,000 miles, so hardly long term.

    The latest replacement also came with updated motor mounts, which are rumored to play a role in the solution.
     
  15. mellington

    mellington Member

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    Are these faults related to any particular model for example the P85s are more prone to the issue due to the extra grunt?
     
  16. nwdiver

    nwdiver Active Member

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    Purely anecdotal but it seems the P85s are more likely to be a little 'noisy' but less likely to fail.... that's based on a sample size of ~3....so.....
     
  17. loganss

    loganss Member

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  18. e4chan

    e4chan Member

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    I had a clunking noise and the SC was nice enough to replace my drive unit and now it is very quiet. They initially didn't replace anything; SC tightened some bolts and other things....but didn't really fix the issue. Then they offer to replace the drive train...it's great now.
     
  19. Oyvind.H

    Oyvind.H Member

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    Have anyone heard about a permanent fix for the drive unit problems? A Tesla-owner here in Norway is making some statistics regarding the drive unit problems. Out of 307 answers, 46% report "no problems with drive unit". 3% have had total breakdown, and the rest (51%) have humming sound on highways and clunk-noise when shifting from acceleration to regen in low speeds.
    Because of DU shortage it seems that almost noone in Norway gets DU swap at the moment. The DUs are reserved for cars who break down.
     
  20. yobigd20

    yobigd20 Well-Known Member

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    the fix is a drive unit replacement with a refurbished one, and the refurb'd one should be shimmed/repaired so the noise doesn't occur anymore. plus during the reinstall they reroute some of the power cables and dampen the sound so that any noise that returns is muffled and almost completely inaudible (particularly the balloon squeal).
     

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