Welded suspension bushings | FerrariChat

Welded suspension bushings

Discussion in 'Mondial' started by srephwed, Jan 14, 2017.

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  1. srephwed

    srephwed F1 Veteran
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    Apr 29, 2012
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    fred brown
    Rain, sleet, snow and cold here in Maryland. If I can't drive it I might as well work on it. Decided to replace worn control arm bushings and some other things while it is nasty. I am working on the front. The old bushings were tack welded in two spots. Should I tack the new ones as well? Thanks in advance for any help.
     
  2. Bell Bloke

    Bell Bloke Formula 3

    Dec 6, 2012
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    They should be pressed in, sounds like someone got carried away or maybe they were a poor fit for some reason.
    Regards Bell
     
  3. absostone

    absostone F1 Veteran
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    Yes press in then tack weld in two locations.
     
  4. afterburner

    afterburner F1 Rookie
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    Must be tacked in place. Insert into wishbone, mount and torque, set the car down, then tack.
     
  5. absostone

    absostone F1 Veteran
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    Tack before its on the car
     
  6. Newman

    Newman F1 World Champ
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    Why would you do that? Press them in then tack them then install the arms. We're not working on the space shuttle here.
     
  7. godabitibi

    godabitibi F1 Veteran
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    #7 godabitibi, Jan 15, 2017
    Last edited: Jan 15, 2017
    I think he mean to let the bushing to rotate to it's normal seating position to avoid pre-torsion on the bushing.
    I like to leave the bolt loose in a bushing until the car sit on its wheels and then tight the bolts. That give the rubber in the bushing no torsion when the car is normaly sitting. When you tight a bushing with the arm leaning in the down position when the car is jacked up when you put it down the bushing is then torsioned. All the time when sitting. I like to think it leave the rubber a better life expectancy when tightened in the sitting position.
     
  8. godabitibi

    godabitibi F1 Veteran
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    Thinking about that it would be cool to test it. The torsionned bushings act like a spring. I wonder with all 16 new bushings installed at the same time with the car up and tightened how much higher the car would sit compared to sitting on loose bolts with no torsion.
     
  9. Martin308GTB

    Martin308GTB F1 Rookie

    Jan 22, 2003
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    Would be fun :)

    Claude,
    I agree. Pressing in the bushings, tack weld them and install the A-arms on the car letting the bolt loose. But moreover, I drive around a few hundred meters, to get the car sitting completley, because I noticed, that after just setting the car down the ride height is around 10-20mm higher, than after driving.
    Then I get back on a four post lift (all wheels on the ramps) and torque the bolts and nuts.

    Your proposal of testing the stiffness after tightening with the car up is interesting, but I would worry about damaging all bushings immediately.

    Best Regards
    Martin
     
  10. moysiuan

    moysiuan F1 Rookie
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    Is there any other car that tack welds a bushing in like this? Seems odd, and any welding of a bushing is going to transmit heat to the rubber, sounds like a bad design idea to me.
     
  11. srephwed

    srephwed F1 Veteran
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    Thanks to every one for the advice. I tacked them back in. I did so because I think the intention was not to keep them from falling out but to keep them from spinning in the bore. Excellent point to make sure suspension is loaded before tightening bolts. That way it is neutral when at rest. I will post some before and afters when It is complete. Thanks again to everyone.
     
  12. Alden

    Alden F1 Rookie
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  13. afterburner

    afterburner F1 Rookie
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    Many bushings on older cars were an inner tube and rubber vulcanised on it.
    It was inserted into a long tube welded on the wishbone. The rubber would slide inside that tube when the wishbone moved up and down.

    The Ferrari bushing is an inner and outer tube with rubber volcanized between the two.
    If you hold the inner tube with the bolt, the outer tube with turn inside the wishbone's narrow support area while it moves up and down, due to the rubber's resistance.
    This will wear out the contact area and lead to play, causing alignement issues and noise, increased by corrosion.
     
  14. Bell Bloke

    Bell Bloke Formula 3

    Dec 6, 2012
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    Mine are just pressed in, no welding or tacking and procedures as Claude described here. My Lotus and Lamborghini also just pressed in. If Ferrari tack them then fine but it's unnecessary I think. If you really want to lock your bushings in there are many modern joining compounds for doing it. Regards Bell
     
  15. Martin308GTB

    Martin308GTB F1 Rookie

    Jan 22, 2003
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    It's just a measure of precaution. It's all a tolerances thing. If the press fit is near the lower tolerance range limit it will probably work without welding. But if near the upper range limit it may slip and destroy the A-arm.
    When I did my bushings job I actually noticed, that all were slightly different regarding the required force to press in the bushings.


    Best Regards
    Martin
     
  16. srephwed

    srephwed F1 Veteran
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    #16 srephwed, Jan 16, 2017
    Last edited by a moderator: Sep 7, 2017
  17. Martin308GTB

    Martin308GTB F1 Rookie

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    This is the reason why I even drive around a little bit with loose bolts before tightening all.
    Just putting the car onto its wheels is not enough for settling the suspension completely.

    Best Regards
    Martin
     
  18. srephwed

    srephwed F1 Veteran
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    Good advice. If it ever clears up here I'll try it.
     

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