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Will try here too.... Prius can't do a u turn safely

Discussion in 'Gen 3 Prius Technical Discussion' started by WickedV, Apr 20, 2017.

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  1. Yippeekyaa

    Yippeekyaa Active Member

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    Just being a skeptic so forgive me if I come across as harsh, but....... is a full lock uturn that much of an occurrence in your daily driving that it is that big an issue? Maybe the issue is you and not the car. The dealer can't replicate the problem after several tries right? So far, no one here has this problem nor has seen it mentioned on this forum. And the issue only occurs under full lock uturns right? Maybe changing your driving habits would be the simplest and easiest fix. Again, sorry for sounding harsh.
     
  2. WickedV

    WickedV Junior Member

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    The dealers who could not repeat the problem were lifting the vehicle for inspection prior to driving it and by unloading the suspension they were changing the parameters of the problem. Once the car was driven enough to settle the problem returns.
    Full lock is not a daily occurrence, though a few times a month it is. Without regard, no other Prius or any other brand has this problem.
    Not changing anything, the car is faulty period. Tho are you are suggesting a Prius or any Toyota has to be driven with an air of caution because it's unable to do what it should?
     
  3. WickedV

    WickedV Junior Member

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    and explain why after the car has been lifted to inspect it has no issue with doing a full lock u-turn and why is it, that it has a fit when it returns to it's stock height?
     
  4. Yippeekyaa

    Yippeekyaa Active Member

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    I don't get where you think I suggested that the problem was Toyota or Prius. I'm simply saying that the problem may be you and not the car. It hurts like hell when I accidentally hit my thumb with a hammer, therefore I try my best to not hit my thumb with a hammer. If the problem you are having only occurs under full lock uturns then maybe you simply don't do full lock uturns. Try 7/8th lock uturns instead. And for the second time, I apologize if I come across as harsh. I won't apologize a third time.
     
  5. WickedV

    WickedV Junior Member

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    I get what you are saying, but changing my driving style dependent where the car is ride height wise is MADD.
    Of the rack / lift all is good, settled it troughs a fit.
     
  6. WickedV

    WickedV Junior Member

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    While I may be a biggish guy, the car was purchased for my wife. She sufferers from anxiety that worsens when bad crap like this happens and this car with this problem is not something I want my wife to drive.
    No other Prius has this problem, just this one. I really do not understand why it can't be fixed.
     
  7. fuzzy1

    fuzzy1 Senior Member

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    I rather enjoy having a car that can U-turn out of a parking space on many (very low traffic) streets where none of my previous vehicles could without a two point turn.

    Or, at the official U-turn spots on divided arterials, being about to pull them quick with a full lane of margin where bigger vehicles must do them slow while making sure they can clear the far curb.
     
  8. Sam Spade

    Sam Spade Senior Member

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    Maybe you should.

    I believe he stated:
    The service people ARE able to reproduce the problem and they are NOT able to reproduce it on any other car that they have tested.

    If I were chasing this problem, I would be looking at the ABS system.
     
  9. bisco

    bisco cookie crumbler

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    prius is the first car i've owned where full lock doesn't cause a power steering hiss. you feel like there's a mechanical stop, preventing it from going too far.
    and my previous car was a 2001 taurus. abysmal in full lock. made you want to back off a bit.
     
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  10. fuzzy1

    fuzzy1 Senior Member

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    I'm also suspecting that the controllers in the electric system are programmed to not create high forces and stresses at the end stops, so are not running into the problems of the old hydraulic systems at the locks.
     
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  11. bisco

    bisco cookie crumbler

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    interesting, i have no idea how the whole steering system works.
     
  12. ChapmanF

    ChapmanF Senior Member

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    In a conventional car, that hiss is the power steering fluid being pumped through the relief valve; the valve is there on purpose because the pump always turns when the engine runs, so when the steering reaches lock the fluid still has to go somewhere, and the relief valve lets it. So it's doing what it's supposed to and isn't hurting anything, except your serenity if you don't like the sound.

    You don't get that sound in a Prius because there's no pump, no fluid, no valves. :)

    My sister's Forester had a problem last fall that there turned out to be a service bulletin for. That relief valve had a weaker spring, so it would start relieving not only at lock, but under any sort of extra-high steering load, like slow maneuvering in a paved parking lot. Made a horrible judder in the steering as the assist rapidly cut in and out. Sure enough, the service bulletin was just to replace the ~ $30 relief valve.

    -Chap
     
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  13. fuzzy1

    fuzzy1 Senior Member

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    Fortunately, newer Foresters, such as my 2014, have electric power steering, not the older hydraulic system.
     
  14. ChapmanF

    ChapmanF Senior Member

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    The electric steering in Gen 1 Prius had some interesting, ah, features, that happily were worked out by Gen 2....

    -Chap
     
  15. WickedV

    WickedV Junior Member

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    Bisco, take a look at the link...

     
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  16. WickedV

    WickedV Junior Member

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    Bisco, to better answer your and many others questions with regard to EPS, as there is no hydraulic pump as found on conventional power steering, there is no shudder when the pump is dead headed at end of the rack's stroke.
    The best I can ascertain is the rack is limited to internal stops on the I.D. of the rack and pinion Assembly. This was confirmed while speaking with Toyota Corp.
    Keeping in mind that the Toyota Help line is correct on their statement, I requested a print as I would like to make and install Delrin bump stops (of sorts) at each end of the rack and thus eliminating my car's problem.
    While any addition to the length of the rack may effect the turn radius, I'm not concerned about that, I want the car not to throw a fit when making a U turn.
    Toyota has had many issues (worse than the USA foot mat debacle) in Europe with the rack and pinion assembly and world wide as the Prius shares it's EPS with many other cars.
    Now without actual production prints. it's really hard to say what need's to be done.
    All I know is my car should not have this problem.
     
  17. bisco

    bisco cookie crumbler

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    are you assuming they are not, or cannot fix it?
     
  18. WickedV

    WickedV Junior Member

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    Not
    Not assuming anything really, only this I do know is they have not yet fixed it.
     
  19. bisco

    bisco cookie crumbler

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    what is their latest? if you start modifying it, won't that let them off the hook?
     
  20. WickedV

    WickedV Junior Member

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    These are my thoughts only.
    What happens on my car only happens at full lock and a certain ride height.
    Modifying the ride height will not help as that will change with wear and tear, i.e. springs will sag as the years roll on. ect and of course the car will settle.
    Shortening the stroke of the rack should never change and thus will eliminate this problem.
    Again, I would really like to have the production print and then could verify if the parts were made to spec, or if the design was faulty from the start.
    Normally in my line of work at least the problem stems from the manufacturing side of thing and not the design.
    When the factory maintains their equipment, this does not happen.
    Much like maintaining your car.
    Every attempt to have the rack and pinion assembly change has been met with "it must fail first"
    Really it frustrates and saddens me, I'm pretty sure Toyota has good techs, but Toyota limits them to blind part changers.