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What happens when car is on lift, supported on jack pads, and jack mode is disabled?

Discussion in 'Model S' started by artsci, Mar 18, 2015.

  1. artsci

    artsci Sponsor

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    Curious if anyone knows the answer.

    If the car is on a lift, supported from the jack pads, and jack mode is disabled, how does the self leveling behave? Can one set the suspension to the various levels on the touchscreen or does it become unreliable or uncontrollable? Inquiring minds want to know:)
     
  2. yobigd20

    yobigd20 Well-Known Member

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    Well I was always told NOT to do that bc it could damage the suspension components so I'm not going to be the guinea pig. Who knows. Maybe it's more of a safety thing
     
  3. patrick40363

    patrick40363 Member

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    You are supposed to raise the car to the highest level and then put it in jack mode.

     
  4. yobigd20

    yobigd20 Well-Known Member

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    It's because of death. Death will find you.

    6289a4a0f4faba6a223201c242072656.jpg
     
  5. yobigd20

    yobigd20 Well-Known Member

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    The whole page (yes like mentioned above make sure it's set to very high before engaging jack mode):

    361ce0f127637fd06050ae1ff9612495.jpg
     
  6. JohnQ

    JohnQ Active Member

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    I expect artsci is fully aware of the dire and deadly warnings if he does so. But what happens if you ignore said warnings? Is it like the top step of the ladder where if you have decent balance nothing happens? Or is it like a plastic bag over your head?:scared:

    When I saw the title of the thread I was hoping he experimented and would tell us.
     
  7. artsci

    artsci Sponsor

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    I think you're right about the safety reason. But when it's on a lift with the wheels off and supported by the lift arms at the jacking points nothing dangerous can happen. Damage to suspension components when it tries to self level is a possibility for sure but that's what I'm trying to understand.
     
  8. apacheguy

    apacheguy Sig 255, VIN 320

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    My thought as well. I don't see how it can crush you if it is physically supported by a lift with the wheels off the ground. I always thought the reason was purely to prevent damage to the suspension components.
     
  9. Danal

    Danal electricmotorglider.com

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    I was told during my orientation... (and we all know how consistent and accurate those statements have proven themselves over time) ... that the danger comes during the lift and/or let down. The car might try to level on any corner at the same time the jack tries to move whatever the jack is moving. That could, in turn, knock the car off the jack. Even with the wheels chocked, etc.

    If those statements are true, then I don't see any potential for harm if the car is fully supported in such a way that none of the four wheels can possibly touch anything external to the car during their entire suspension travel. Hurt themselves? You are kidding, right? A car suspension is designed to travel from wheels above ground to the fully compressed upper "snub" with the full weight of the car involved. When everything is off the ground? Again, as long as wheels no touchy something non-Tesla, no harm, no foul.

    Just my opinion, of course. Would I try it? Hmmm... OF COURSE NOT. At least I'm not putting it in writing on the internet. :)
     
  10. bxr140

    bxr140 Member

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    Regardless of the suspension setting it will be fully extended once up on the lift. Gravity is helping that happen in addition to the airbag pressure, so you're not going to be able to make your car wave its arms or anything even if you completely bled the airbags.

    At ambient pressure the airbags should still hold shape, so there's likely little or no damage that you could do even if for some reason the self leveling system completely bled the airbags.
     
  11. FlasherZ

    FlasherZ Sig Model S + Sig Model X + Model 3 Resv

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    The car will throw an error - "suspension height too high". On a properly attached lift, it likely won't be harmful... it's more a warning for lifting only a single corner, or perhaps just a half of the car, where it will attempt to compensate to level the car.
     
  12. patn

    patn Member

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    I concur with the previous post - I think this warning is about a guy at home jacking up the car at one point and then crawling under it, only to have it self-level back down on him.
     
  13. billarnett

    billarnett Member

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    What happens if you drive fast enough over the crest of a hill such that all 4 wheels leave the ground?
     
  14. Danal

    Danal electricmotorglider.com

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    Fun happens.

    And, yes, that's exactly the point. No harm.
     
  15. artsci

    artsci Sponsor

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    My car will be on on a lift as describe on Monday am. I guess I'll be the guinea pig.
     
  16. GaryREM

    GaryREM Member

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    Good luck.

    Since the suspension normally is normally under compression, the normal response on finding the car too high would be to reduce pressure and if too low to increase pressure.

    When on the lift, the shocks will extend and I assume the system will try to respond by reducing pressure.

    Does this mean that when you lower the car the pressure will initially be too low until the car senses this and pressurizes the shocks back up?

    Why would you want to try this if there is any possibility of damage?
     
  17. gnychis

    gnychis Member

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    Hi all,

    I'll be your guinea pig (with active air suspension). I have forgotten to tell 2 people servicing my car about this.

    First was in California, someone jacked up the right front side to repair a flat. I got out of the car to tell him my issue and he just immediately slid a jack under it before I had a chance to think: "let me raise the car and put it in jack mode!" When he jacked up the car I didn't hear it try to re-level itself in any way at all. That's not to say it couldn't, it might. But in this case I never saw/heard it try to relevel.

    IMG_20140916_173207.jpg

    The second time was in Boston when someone switched my tires to winter tires. They pulled it in to their garage and without me thinking about it, I also forgot to tell them to put it in jack mode.

    Okay, so what happened in both times? When the car comes "back down" it is NOT leveled at all. It is either sagging to one side, and it is VERY low (well below the lowest setting). All I did in both cases was raise the car back up to "very high" and then bring it back down to standard and it relevels itself out. Haven't noticed any issues.

    I need to tie a string to my finger to remind the next person touching the car about this...
     
  18. SabrToothSqrl

    SabrToothSqrl Active Member

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    Last night I apparently did something against the manual... I had a floor jack under the front left, (in jack mode) but I had it plugged in charging... apparently it says not to charge while it's jacked,... but the service center had all the cars recharging while up on the big lifts.... damn I wish I could afford one of those for my shop.
     
  19. nrcooled

    nrcooled P#8946 VIN 03225

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    I forget to put the car in jack mode a lot when doing routine maintenance stuff and it has never done anything to bring about death. I wouldn't recommend it but nothing has happened.
     
  20. jerry33

    jerry33 S85 - VIN:P05130 - 3/2/13

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    On my car you can't put the car in jack mode or raise the suspension when the car is off, so I'm not sure how you could do this when the car is plugged in as the car won't turn on when plugged in.
     

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