13 SPEED Shifting

Discussion in 'Trucks [ Eighteen Wheelers ]' started by jerseycowboy, Nov 17, 2010.

  1. jerseycowboy

    jerseycowboy Bobtail Member

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    Dec 30, 2009
    Fort Worth
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    Hello Truckers, Just bought a Truck with a Mack 13 speed, I'm a little rusty on my shifting, use to ten speeds, what is the proper way to down shift a 13. I seem to be able to up shift but have a little problem down shifting. Do I drop the RPM to 1000 then rev it up to 1500 then shift the red button or what is he proper way? seems I get stuck with just a bit of grinding and then have to go back to the high side or shift to the lower gear from OD to D drive like from 13th OD to 12 D but how so I drop from 13 OD to 13D without any issues. Thanks alot
     
  2. BigDaddy01

    BigDaddy01 Bobtail Member

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    Nov 17, 2010
    Texas
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    Here is how I down shift: while in top gear with the jake on or slowing down with the service brakes, flip the red switch, when the rpms get to about 1100 step on the throttle lightly until the transmission shifts. Then slow down again, when your rpm's get to 1100, flip the red switch and drop to the next hole. repeat until you slow down enough. Of course the rpms will depend on the specific engine and transmission ratios in your truck. Listen to the engine and see what feels right. Hope this helps a little, practice will make it easier.
     
  3. Bent Wrench

    Bent Wrench Medium Load Member

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    Aug 11, 2009
    Cornholio, OR
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    The RPM difference between gears when using the red switch is ~200.

    I don't think there is any reason to split going down though (maybe just once to get the red button to the rear so you can get to low range if you need it)

    Preselect, take the load off the gears, shift to neutral, match RPM & shift. Just like a shift of a main gear just a different RPM spread.

    There is no need for any "grinding", you can shift with 1 or 2 fingers. You can "feel the grind" without making any noise and wearing out stuff.
     
  4. heavyhaulerss

    heavyhaulerss Road Train Member

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    go on youtube & type in shifting 13 speed
     
  5. Trouble65

    Trouble65 Medium Load Member

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    Jan 11, 2009
    Ontario Canada
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    You beat me to it.

    Go on Youtube you will see everything.
     
  6. Pablo-UA

    Pablo-UA Road Train Member

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    Borispol, Ukraine
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    i newer used 13st tranny. I draw 12 st, 16st and 18st... well, about this splitter. I used to shift 1 1/2 step usually, I drive at 4H and I shift to 6L... sometimes at crusing speed at slight hill I drive at 8H and truck runs up at 8H, but... at 8L fuel milage is a bit better....
     
  7. heavyhaulerss

    heavyhaulerss Road Train Member

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    What? :biggrin_2556:
     
  8. Pablo-UA

    Pablo-UA Road Train Member

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    Borispol, Ukraine
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    yeah! sometimes a bit lower gear - better fuel milage if you cant drive a bit faster...

    I used to drive EU trucks with tranny with splitter and really sometimes I have 1100 rpm at 8H and 1300 at 8L and fuel consumption changes about for 1-1.5 l/100km!

    it is my experience with Mercedes Actros.

    So if you can use splitter, it saves fuel.
     
  9. melpromud

    melpromud Medium Load Member

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    Jan 29, 2010
    camden ny
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    When useing the spliter step down on the fuel to down shift, let up on the fuel to up shift. The easest way to learn a 13 speed ( or 18 speed) down shift is to split to 13 direct. Move red button down, step down on the fuel till the trans shifts. then down shift whole gears like its a 9 speed.
     
  10. mitchtazz

    mitchtazz Road Train Member

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    Sep 6, 2009
    Lake Wales, Fl
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    lol, they're from the ukrain, so the grammer is a little off but i'll help. They were trying to say that by using the splitter (cause someone asked why you'd use it to downshift) you can increase the trucks fuel mileage because the RPM wouldn't have to be raised an extra 200RPM to make up for the half gear that was skipped by not using the splitter. Lower RPM's equal better fuel mileage.
     
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