Advantages of a spread axle trailer?

Discussion in 'Questions To Truckers From The General Public' started by Bobg, Feb 12, 2009.

  1. Daisydog

    Daisydog Bobtail Member

    Joined:
    Mar 19, 2009
    Messages:
    2
    Thanks Received:
    0
    Location:
    Nebr
    0
    Thanks for deciphering my script; yes my question was how am I getting such a difference in my axle weights? Have looked the trailer all over and have not seen any cracks in the frame, but since you said so I'll specifically look for that. There are three valves in a box on the side of the trailer: two manual dump valves (one is possible to be controlled from the cab but not operational that way) and between the two is what looks like an equalizer. I am wondering if that is faulty or if that's possible.
     
  2. TripleSix

    TripleSix God of Roads

    Joined:
    Apr 10, 2009
    Messages:
    18,511
    Thanks Received:
    129,672
    Location:
    Copied in Hell
    0
    Reason for the spread:

    Regular tandem trailers flex in the middle. When going down the road, they flex and bend. This flexing and bending heats up the frame and can eventually cause the metal to crack and fail. A spread axle trailer has an axle towards the center of the trailer. This cuts out alot of the flexing and actually gives a smoother ride.
     
    KB3MMX Thanks this.
  3. pullingtrucker

    pullingtrucker Road Train Member

    Joined:
    Dec 21, 2008
    Messages:
    1,185
    Thanks Received:
    598
    Location:
    Fostoria, Ohio
    0
    I would start by looking into these valves. It sounds like you got a different or modified leveling system. On a typical spread axle air ride suspension the manufacters put the leveling valve on the rear axle with a air line that will have a manual or electric dump valve to dump the whole suspension. Then the line will go to the front axle and the rear axle. On the line going to the rear axle is where the electric dump valve is placed to dump the rear axle air for tight turning. When ya start putting more valves in the system to do different things it gets more complicated. If all else fails go back to this simple system and see where your weights are and go from there.

    On a side note I have seen in the "old days" when we re-arched trailers we would have to install spacer plates on top of the lead axle air bags. But this only happened when we got the arch over 6-7 inches on a 48ft trailer. But most trailers today have little or no arch or the arch is built into the frame.
     
    KB3MMX Thanks this.
  4. Les2

    Les2 Road Train Member

    Joined:
    Jul 25, 2008
    Messages:
    5,150
    Thanks Received:
    2,288
    Location:
    kicked back in my lazyboy...
    0
    All trailers flex and bend or they'd break! The flexing of a trailer also helps the ride of it.
     
    KB3MMX Thanks this.
  5. TripleSix

    TripleSix God of Roads

    Joined:
    Apr 10, 2009
    Messages:
    18,511
    Thanks Received:
    129,672
    Location:
    Copied in Hell
    0
    Reread my post. Now, where in my post does it say that spread axle trailers dont flex?
     
  6. Les2

    Les2 Road Train Member

    Joined:
    Jul 25, 2008
    Messages:
    5,150
    Thanks Received:
    2,288
    Location:
    kicked back in my lazyboy...
    0
    I think you mistook my post to you. There isn't much difference in the flexing of a trailer with or without a spread other than the place it flex's. Maybe this isn't so with a van, I don't know and don't really pay any attention to them.
     
  7. wtm

    wtm Light Load Member

    Joined:
    May 11, 2009
    Messages:
    118
    Thanks Received:
    18
    Location:
    south
    0
    Advantages
    Easy to load without overloading the tandem
    pull straighter atleast too me
    Keep the tire dealers in business

    disadvantages
    keep the tire dealers in business
    pain in the arse to back in tight places
    They crack worse from draging the axels in a bind
    I have also noticed that when u put 40000 over the spread the tires tend to blow worse then a tandem even with the same amount "overloaded tandem" this is my experience but it could be because on my spreads theres always atleast one thats about ready to go.
     
  8. KO1927

    KO1927 Medium Load Member

    Joined:
    May 19, 2009
    Messages:
    569
    Thanks Received:
    263
    Location:
    NH
    0

    Could you explain this with a little more detail? I don't understand why not, if this is possible with the close tandem.

    Apologies if this is sarcasm that I am misreading. Jokes are often lost when translated to the computer screen.

    EDIT: I do see the smiley, just don't want to pass up the chance to increase my knowledge, even if the knowledge is disguised as a joke.
    Thanks.

    -Ken
     
  9. heyns57

    heyns57 Road Train Member

    Joined:
    Dec 30, 2006
    Messages:
    2,209
    Thanks Received:
    1,011
    Location:
    near Kalamazoo Speedway
    0
    Ken, the comment about changing gears while turning with a spread axle was meant as a joke with a lot of truth in it. A spread will drag while turning and therefore cause the truck to almost stop or lose momentum, making it difficult to change gears unless you planned to downshift two gears. With a spread, it is necessary to keep the power to the wheels while turning. A driver who operates a tandem every day will be in for a surprise the first time he turns a corner with a spread axle. Most of us do not change gears while turning regardless what type of trailer we have.
     
    KB3MMX, bbechtel16 and KO1927 Thank this.
  10. KO1927

    KO1927 Medium Load Member

    Joined:
    May 19, 2009
    Messages:
    569
    Thanks Received:
    263
    Location:
    NH
    0
    heyns57- thank you for the explanation.

    -Ken