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Wandering/darting issue

Discussion in 'Flat Fender Tech' started by garage gnome, Feb 5, 2015.

  1. Feb 5, 2015
    garage gnome

    garage gnome Rust polisher Sponsor

    Western MA
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    My '46 that I just finished building likes to wander or dart as I'm driving it down the road. I'd say the problem starts at 35mph. My speedometer cable broke so I don't have the exact speed. It has 2.5" lift yj springs and is spring over. I put the rocky road high steer kit in too. New steering box as well. Have the ties towed in too. The tires are 34x10.5 TSLs. It has a steering stabilizer as well.

    Is it because I'm so tall that it wanders or am I overlooking something? I've driven a few stock trucks that do this as well.
     
  2. Feb 5, 2015
    nickmil

    nickmil In mothballs. Sponsor

    Happy Valley, OR
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    How much are you toed in? What is your caster set at? What does your drag link angle look like? Ball joints or trunnion bearings tight? Wheel bearings adjusted? Do you have a locker in the rear?
     
  3. Feb 5, 2015
    duffer

    duffer Rodent Power Sponsor 2019 Sponsor

    Bozeman, MT
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    What Nick said but insufficient caster would be first on my suspect list.
     
  4. Feb 5, 2015
    lynn

    lynn Time machine / Early CJ5 HR Rep Staff Member Sponsor

    Huntingdon PA
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    Toe and caster are the usual suspects. "Darting" description makes me think first of caster, as John said above.
    What is your caster set at now?
    Try 5-6° positive caster.
    Find out what your current caster is, and what you need to reach 5-6°
    I think you can use steel shims in your SOA application, much as many of us have used in SUA application..
    IIRC in an SOA application you'll need to put the thin end toward the front in order to rotate the axle a bit counterclockwise (In SUA, fat end goes to front)

    Here's a source for shims:
    http://www.4crawler.com/4x4/ForSale/Shims.shtml#Introduction

    HTH
     
  5. Feb 5, 2015
    garage gnome

    garage gnome Rust polisher Sponsor

    Western MA
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    Drag link is very close to flat. I don't remember how much I towed it in. I'll have to check when I get home from work this weekend. I have an OX locker in the back, but that doesn't matter since it is disengaged. Would I have screwed up my caster angle when I angled the diff a little for my driveshaft angle? The front is a Dana 30 NT.

    I've been thinking about going to stock YJ springs. Right now I think it is a bit too high.
     
    Last edited: Feb 5, 2015
  6. Feb 5, 2015
    nickmil

    nickmil In mothballs. Sponsor

    Happy Valley, OR
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    Angleing the pinion up will go to less positive caster, so probably.
    Take an angle finder on the bottom of the lower ball joint (nice flat spot to measure from) and determine what your caster is. The top of the knuckle should be angled back and bottom forward of zero. Report back with measurements. As others have said 5-7 degrees positive is what you want. Positive caster is with the top of the knuckle angled back from vertical. Toe usually causes wandering but in extreme cases can cause the vehicle to "dart". Again, make sure all other components are tight as play can be cumulative and cause similar issues.
     
  7. Feb 5, 2015
    uncamonkey

    uncamonkey Member

    Greeley CO
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    Yes, all of what people have said is correct. The only other things I can throw in is your tires, some of them want to follow the wrong things in the road. The SOA isn't helping you either.
     
  8. Feb 6, 2015
    djcj3a

    djcj3a Member

    Ukiah, CA
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    I was going to say tires too. I had a set of the 34x10.50 LTB's on a toyota about 8 years ago. They were great off road, but nearly unusable on the freeway. They would wander like crazy, and wouldn't balance right.
     
  9. Feb 6, 2015
    garage gnome

    garage gnome Rust polisher Sponsor

    Western MA
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    Caster angle is 0° and it is toed in about 2.5°. Guess my caster is what the problem is!
     
    Last edited: Feb 6, 2015
  10. Feb 7, 2015
    Willys Motors

    Willys Motors New Member

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    I hope you mean .25 degrees toe in.
     
  11. Feb 7, 2015
    garage gnome

    garage gnome Rust polisher Sponsor

    Western MA
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    I fixed the caster today and it drives like a dream now! Thanks guys!
     
  12. Feb 7, 2015
    47v6

    47v6 junk wrecker! Sponsor

    Washington DC.
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    Awesome!
     
  13. Feb 10, 2015
    lynn

    lynn Time machine / Early CJ5 HR Rep Staff Member Sponsor

    Huntingdon PA
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  14. Feb 10, 2015
    Walt Couch

    Walt Couch sidehill Cordele, Ga. Sponsor 2019 Sponsor

    cordele, Ga.
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    :D:D:D Happy for you. We love success.
     
  15. May 8, 2019
    Buildflycrash

    Buildflycrash Member Sponsor

    Gulf Breeze FL...
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    I just got on the road yesterday, this is exactly the same issue I'm having, darting around at just about any speed. I'll check my caster tonight and report back here.
     
  16. May 9, 2019
    y2grey

    y2grey Member

    Fayetteville NY
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    Great to hear you got it resolved! We RR-SOA guys need to form a group. Mine is a n/t 30 with custom stock width springs and "Z" link. Giving serious thought to the high steer kit.
     

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