Shifting

Discussion in 'Trucks [ Eighteen Wheelers ]' started by notarps4me, Mar 11, 2007.

Drivers do you

  1. *

    float?

    65 vote(s)
    43.6%
  2. *

    double clutch?

    16 vote(s)
    10.7%
  3. *

    or both?

    65 vote(s)
    43.6%
  4. *

    have an auto tranny?

    6 vote(s)
    4.0%
  1. jorlee

    jorlee Light Load Member

    197
    83
    Feb 17, 2007
    ND
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    Nope won't hurt it, clutch just stays engaged, and in the tranny all that's happping is one sliding gear is coming out of mesh and another going in. Clutch linkage, and the clutch probably gets more wear when using it every shift than, just floating.

    Nothing can be hurt unless you grind them too much, which is bad whether or not the clutch is used. Just don't rest your foot on the clutch, or slam the clutch to the floor when double clutching.
     
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  3. 25(2)+2

    25(2)+2 Trucker Forum STAFF Staff Member

    18,758
    45,912
    Sep 18, 2006
    the road less travelled
    0
    From what I've read, heard, etc about auto-shifts, they are automated float shifting , done by electric or pneumatic actuators, and controlled by computer.

    Full auto- with a torque converter is the only thing that is related to an automotive transmission.

    AJ
     
  4. NyteWulf

    NyteWulf Bobtail Member

    42
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    Feb 23, 2007
    Blacksburg, Va.
    0
    So all you do is shift, no cluth involved at all. Or is there a trick to it? Do schools teach this?
     
  5. jorlee

    jorlee Light Load Member

    197
    83
    Feb 17, 2007
    ND
    0
    DMV require double clutching for driving Test. Floating is the same principle of double clutching, without the clutch. Which would be useful if your linkage were to break, you would be able to contine normally to a truck shop for repair.

    Upshifting-- Release pressure on transmission by easing off the fuel pedal, while pulling to neutral, then putting into next gear when rpm falls to the right rpm, repeat

    Downshifting-- release pressure on transmission by giving a little rpm, move stick to neutral, raise rpm, put stick into lower gear repeat

    It's the same principal as double clutching.

    upshift clutch pull stick to neutral clutch stick into gear

    downshift clutch neutral raise rpm clutch gear

    Just skipping the entire clutch movement, which breaks torque on the transmission, making it easier to shift. With floating the torque break is down with the go pedal, which is how a Auto shift shifts. I'd assume the ultra shift does it the same way.
     
  6. MickeyFIN

    MickeyFIN Light Load Member

    212
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    Mar 6, 2007
    Turku, Finland
    0
    float up double clutch down even in offroad conditons So was I thought to drive a truck in the army as it´s the fastest way to avoid getting cought under fire.
    Nowadays I have a 18speed Fuller to work with.
     
  7. Brickman

    Brickman Trucker Forum STAFF Staff Member

    12,908
    12,210
    Sep 17, 2006
    WY
    0
    Double clutch for driving test might depend on the state. 6 or 7 yrs ago already WY did not require double clutch.
     
  8. Burky

    Burky Road Train Member

    Mich did not require double clutching when i took the test, and frankly, once the tester saw I knew my way around a transmission, from that point onwards he had no further interest in my specific technique.
     
  9. slim66

    slim66 Bobtail Member

    30
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    Mar 3, 2007
    0
    Eaton Fuller (RoadRanger transmissions) has an interesting video (for newbies, anyway) that somebody on this site once posted a link to. According to Eaton Fuller the advantage to double clutching is that using the clutch 'breaks the torque' on the transmission and reduces the stress on the gears when the transmission is brought into neutral when the gears are floated, and this is when damage is most likely to occur.

    I would think if one is proficient at floating and can do it consistently without clacking or grinding the gears that it wouldn't hurt the tranny but that's a big if.
     
  10. MickeyFIN

    MickeyFIN Light Load Member

    212
    6
    Mar 6, 2007
    Turku, Finland
    0
    Actually it takes the Stress of the Forks that moves the gears while you use the clutch...
    I sometimes dip the clutch a little just when I feel the stick doesn´t come out softly.
     
  11. Brickman

    Brickman Trucker Forum STAFF Staff Member

    12,908
    12,210
    Sep 17, 2006
    WY
    0


    That torque release also comes from lifting your foot from the throttle before sliding the trans out of gear.
     
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