# Tesla Model S drivetrain issues.



## Moltenmetal (Mar 20, 2014)

It would be a real shame for the whole EV industry if the Teslas started getting a bad rep over this. I hope Mr. Musk takes some of the extreme overvaluation of his company on the market and uses that to make things good for the customers. Unfortunately these products remain entirely outside my price range, but if I had sprung for one of them I would be royally p*ssed to have to change a drivetrain every 40,000 miles, under warranty or not!

Guess that even something as plain Jane as a gearbox can be screwed up if you don't pay enough attention to what's new about it.


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## toddshotrods (Feb 10, 2009)

The only real problem they'll have is marketing themselves as being so far above the average automaker. Generally, people who buy new cars have learned to expect the inevitable glitches and recalls. Just watch automotive news, and count the recalls, from the industry as a whole - it's almost mindboggling.

Tesla seems to have awesome customer service, so I doubt it will be a real issue, in the minds of their customers - as long as they don't raise people's expectations too high about what they're purchasing. It's a modern car which, by nature, is almost impossibly complicated; which means there are going to be problems.

We've been evolving for two million years, and we still have a few glitches. How could we be expected to produce perfection?


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## Duncan (Dec 8, 2008)

Hi Guys
The OP asked for this to be moved


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## RIPPERTON (Jan 26, 2010)

Sounds like Edmunds are a bunch of car wrecking butchers.

You know what Rippy would do about the "Milling Noise"

He would have that gearbox out on the floor of his lab in 2 hours designing a new part.
Sounds like a thrust washer issue.


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## aeroscott (Jan 5, 2008)

The old Borg Worner gear box . Remember the 2 speed .


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## piotrsko (Dec 9, 2007)

My money is on the roller bearing holding the input shaft not being able to handle maximum motor torque. BTDT, but YMMV.


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## rochesterricer (Jan 5, 2011)

Its seems the problem is prevalent enough that Consumer Reports downgraded the Model S to "below average" reliability. 

http://www.fool.com/investing/gener...or-drive-unit-problem-decimate-tesla-mot.aspx

I usually can't stand Motley Fool, but this article does a decent job pointing out how this could end up cascading into a serious financial problem for Tesla. I really hope they can get a handle on this before it gets to that point.


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## Karter2 (Nov 17, 2011)

RIPPERTON said:


> You know what Rippy would do about the "Milling Noise"
> 
> Sounds like a thrust washer issue.


I suspect it's more than just a thrust washer !
If the Tesla tech's have any mechanical experience, the phrase "milling sound" would nor have come to mind without good reason.
As others have suggested, that gear reduction takes one hell of a pounding when the taps are opened !
Heat treatment problem of the gear teeth has my money....
....I have seen that too many times, even on the best of industrial equipment.


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## RIPPERTON (Jan 26, 2010)

Love to know how it works though, we can only presume with 2 motors there is no differential so its just 2 stand alone reduction cascades of 3 or 4 gears.


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## Karter2 (Nov 17, 2011)

.?? There is only one traction motor in the Model S. 
The drive train is also a fairly simple direct reduction to a differential.


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## aeroscott (Jan 5, 2008)

The controller looks looks like a motor.


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## JRP3 (Mar 7, 2008)

It must be pointed out that contrary to what Jack claims it is still unknown if the noise is coming from the gear reduction unit, the motor, or the inverter, which are all part of the drive train unit. Few drive trains have actually failed, most have simply been replaced preemptively because of noise. People from the Toyota RAV4EV team seem to think it's in the inverter, as the much lower powered RAV4EV has also had similar issues. Some have said the noise only happens at specific speed ranges, and a failing gearbox would likely make noise at all speeds, increasing as speed increases.


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## rochesterricer (Jan 5, 2011)

Elon responds to the issues with the Edmunds test car:

http://www.huffingtonpost.com/2014/08/01/tesla-review-edmunds-elon-musk_n_5641504.html

He says they were primarily problems with early Model S' and that these issues have been addressed with the newer versions.


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## Karter2 (Nov 17, 2011)

I wonder why Tesla didnt put one of "the newer versions" of the drive train, into Edmunds car the last time they swapped out the unit as they were apparently taking "special" care of that vehicle ?
..Or maybe they did !

I have heard more convincing explanations from dogey car salesmen !


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## rochesterricer (Jan 5, 2011)

Another article with more info:

http://www.greencarreports.com/news/1093713_tesla-model-s-drive-unit-replacements-how-big-a-problem?

Musk seems to be placing the blame for these issues on two main culprits:

1. A loose cable that touches the drive unit and causes vibrations.

2. A differential that needs to be shimmed.


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## rochesterricer (Jan 5, 2011)

Tesla just sent out a mass email and posted on their blog that they are extending the warranty for the drive unit:

http://www.reuters.com/article/2014/08/15/us-tesla-motors-warranty-idUSKBN0GF1XR20140815


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