Fifth Wheel Adjustment

Discussion in 'Experienced Truckers' Advice' started by GreenAction, Nov 24, 2015.

  1. GreenAction

    GreenAction Bobtail Member

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    What is the best placement of fifth wheel if hauling bulk liquids?
     
  2. FuzzFace2

    FuzzFace2 Medium Load Member

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    LPG, hot asphalt & bulk cement/fly ash with a twin screw the pin is between the 2 axles to maybe just a little forward of that.
    Thing is first to watch space between rear of tractor and landing gear of trailer.
    Then what is the weight on each axle front of truck to rear trailer.
    BTW I have not moved the 5th wheel on any of the trucks I have driven.
    Dave ----
     
  3. AModelCat

    AModelCat Road Train Member

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    Once you get it dialed in so you can max out payload without being overweight on either the steer or drives you're good to go. Usually just a bit ahead of center of the drives.
     
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  4. mountaingote

    mountaingote Road Train Member

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    I normally run about 4 notches back from the front, works like a charm
     
  5. MACK E-6

    MACK E-6 Moderator Staff Member

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    I would also add that you mind the distance between the front on the trailer and the rear of the cab.

    Beyond that, my suggestion would be to find the setting that causes the drives and steer to approach their limits while loading at roughly the same rate, which allows one to maximize payload.
     
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  6. Bdog

    Bdog Road Train Member

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    Kind of a strange twist on this question. Looks like I will be getting a tandem truck but I will only be pulling one trailer with my own personal equipment on it and the trailer is relatively light. The trailer has fixed axles and weighs 35k loaded including the trailer weight.

    I could put the fifth wheel all the way forward or all the way back and not overload any axles nor would I have any clearance issues on the front or with the landing gear.

    Any particular place I should set it for better handling or other reasons? I was maybe thinking all the way forward for a shorter overall length but I really don't know.
     
  7. snowwy

    snowwy Road Train Member

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    Like others have said. A setting that max's the steers and the drives. Will give you the most weight on the trailer.

    The tanks i once pulled, were single bore. and weighed 12,5 on steers, 34 drives, 32 trailer. 78,500 was max gross. With a full tank of fuel. If you want to run 1/4 tanks, THEN, you'd be able to get more on the trailer.

    Now, if you can find a way to raise the 5th wheel or front of trailer somehow. You can get more weight on the trailer and gross closer to 80,000.

    THAT'S with the single bores i once pulled. I've seen some tanks that were wider in the back then front. The trailer had a slope towards the rear.
     
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  8. MACK E-6

    MACK E-6 Moderator Staff Member

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    Snowwy makes good sense here.

    This is why tractors that routinely oull tankers are specced with the high stands under the fifth wheels, so as to allow the liquid to shift toward the rear to maximize payload.
     
  9. shivver

    shivver Light Load Member

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    It doesn't matter where the pin is,,,,use common sense. look at the back of the trailer, for they are all different. You want to mimic what is happening in the rear. If there are 3 inches overhanging the the tandems to the rear, you want 3 inches overhanging your drives to the front. Make it even. A fifth wheel too far back will not only attract the dot, but will invite unwanted handling characteristics, such as reduced steering control and a really bumpy ride.
     
  10. kylefitzy

    kylefitzy Road Train Member

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    A fifth wheel set to the rear will do nothing to attract the attention of the DOT. Where do people come up with these things? Almost everyone at my company runs with the fifth wheel all the way back because most of our trucks are front heavy. I'm 12.3k on the steers empty with full tanks.