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Can I cause any harm by switching from Drive to Reverese at < 5mph?

Discussion in 'Model S' started by PhilDavid, Jan 7, 2020.

  1. PhilDavid

    PhilDavid Active Member

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    Could someone who has knowledge about the internals of the Model S drive train explain if any harm can be caused by switching from Drive to Reverse at less than 5 mph?

    Sometimes when making multi-point turns in tight places I notice the car lets me switch between Drive and Reverse and I wanted to make sure there is no harm to the car when doing this.

    I'm especially concerned after reading about the sub-frame failure thread for the motor mount to make sure I'm not causing any problems by doing this.

    Look forward to any insight on this topic.
     
    • Like x 1
  2. Babaron

    Babaron Member

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    Kim from “Like Tesla” on YouTube did a recent video where she demonstrated that very action. The implication was that it was not harmful but I have no direct knowledge that would confirm or refute that assumption.
     
  3. Ande

    Ande Member

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    No. You can't
     
  4. Galinette

    Galinette Member

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  5. Rogue Synapse

    Rogue Synapse Member

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    Came here to post that link but you beat me to it.

    Long story short, a Model S driver experienced a subframe failure where the motor mount actually sheared off because of changing into drive while still rolling backwards. Well, the failure was probably due to some structural or design flaw, but the stress of the motor bucking was the thing that actually precipitated the failure.
     
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  6. Need

    Need Active Member

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    My car won't let me switch to reverse unless I am stopped. I have to do this everyday because I backup onto my driveway. I wonder if it is because I have creep enabled?
     
  7. PWlakewood

    PWlakewood Active Member

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    Same with mine.
     
  8. powaking

    powaking Member

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    I'm sure its fine as long as you don't roll back then smash the pedal once in D. I have to back out of my driveway too and while I do put it into D while still rolling <5mph I do ease into the accelerator.
     
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  9. tyler2323

    tyler2323 Banned

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    No I don’t think you can cause any damage at all. Now if it was a Porsche and had 1 gear like it does it most likely could. But no transmission usually should mean you won’t have any negative effects
     
  10. PhilDavid

    PhilDavid Active Member

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    I have Creep Mode enabled as well and the car absolutely lets me switch between Drive and reveres at less than 5mph and I find this super useful. Of course I'm very gradual with the throttle when switching directions but want to make sure I'm not causing any harm.
     
  11. PhilDavid

    PhilDavid Active Member

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    But don't we still have a single gear? And at these low speeds, a transmission would not really be switching anyway or did you mean how the gears would physically need to switch between Drive and reverse in ICE cars?
     
  12. WarpedOne

    WarpedOne Supreme Premier

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    No.
    If there was any danger, tesla would not let you do it.

    Frame failure?
    I'm sure ludicrous mode has nothing to do with it ...
     
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  13. Galinette

    Galinette Member

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    Noooo, Tesla would never let you do something that may cause failure, and fix it via OTA update later :)
     
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  14. kimvellore

    kimvellore Member

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    I do that every day and I love that I dont have to hit the brakes nor take the foot of the accelerator. For the level of acceleration the car has the small torque change at <5 mph should contribute to no structural damage.
     
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  15. PhilDavid

    PhilDavid Active Member

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    And this switching of direction is "safe" for the single gear transmission as well as the mount?

    I ask about the mount because someone explicitly stated about the change of direction contributing to frame the failure.
     
  16. Hugh Mannity

    Hugh Mannity Mediocre Member

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    I suspect this doesn’t cause any harm. Ive done this every day for the past 4 years with my car. There are no “clunks” or grinding sounds or anything after doing it thousands of times.
     
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  17. ⚡️ELECTROMAN⚡️

    ⚡️ELECTROMAN⚡️ Active Member

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    It feels harmless. Can't see how it would be any worse than launching from a standstill.
     
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  18. AMPd

    AMPd Active Member

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    Uhhh what? The model s has 1 gear
     
  19. Big Toys

    Big Toys Member

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    Keep in mind that you have all that momentum moving one way while the motors are pulling the motor mounts and wheels the other way. If you feel energetic (pun?) you can do the simple math to determine the kinetic energy and momentum of a 4000 lb car moving at 5 mph that needs to be overcome before you even come to a standstill.
     
  20. SO16

    SO16 Active Member

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    I do it all the time. But I ease the accelerator until direction changes.
     
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