Fifth Wheel Coupling

A "fifth wheel coupling" is a device that connects the tractor with the trailer.
The mechanism is simple and can easily be removed.

What is the purpose of a fifth wheel coupling?

  • It adjusts and supports the front and rear load of the trailer,
    which makes safe trailer transportation possible.
  • It is strong and durable, which prevents shape deformation and
    poor functioning during use.
  • The tractor is comfortable and excels in operational feel
  • Ease of maintenance

70% of domestic marketing share!!

As the only domestic coupler maker, we are open to all our customer requests,
and manufacture and market the fifth coupling load of 4t to 60t.
We have 50 years of achivements since Sohshin was still Kakuwa seiki(manufacturing
and marketing since January,1963),and with the trust we have built with other major
domestic manufacturers, we have reached 70% in the domestic marketing share.

1 Axis Fifth Wheel Coupling

Only performs pitching(the control of front and rear movements).
Suitable for high speed transportation,
it softens the movements for the comfort of the driver.


2 Axis Fifth Wheel Coupling

Performs pitching and rolling(the control of front and rear,and sideway movements).
Suitable for heavyweight transportation on rough roads.
Also,when adjusting the movements with the adjusting wedge,
it can be used as a type 1 axis.

Feature of sohshin-made Fifth Wheel Coupling  

1.The materials used for the coupler base are sound and durable

  • Ensures strength and durability with low temperatures
    in cold regions.
  • In the unlikely event of a rollover accident, the highly durable
    properties of the materials will minimize the damage

2.The coupling mechanism consists of a sound, durable and highly reliable “double jaw” system.

  • The kingpin is held by a 360° double-layered grip, extending 
       the wear life of the kingpin and the jaw
  • With regular adjustment of panel gaps, the wear life of the king pin
       and jaw becomes remarkably longer, which reduces the maintenance
       cost of replacements.
  • 3.Appropriate Fifth Wheel Coupling support of a lock guard.

    • A lock guard prevents height  inconsisitency and improper connection by going
      into the open double jaw before being coupled.

    4.Bearing mechanism with abundant variations.

    • "Thick Rubber Bush type"…Absorbs impact with a 360° range,
      and has excellent riding comfort, operational feel, and is also silent when coupling.
    • "Rubber Mount type"…By pinching the bearing in between the rubber, it absorbs
      any vibration or shock, Which creates an excellent operational feel.
    • "Pin type" …While being simple in structure, it has excellent pitching and can fully
      support extremely heavy weight loads.

    Slide Fifth Wheel Coupling 

    Because the position of the fifth wheel coupler is easily adjustable according to trailer,
    there is no need to choose a trailer.
    In addition,with the change of the offset position, the traction is able to drive with efficiency.
    This results in an improvement in running performance and operational feel.
    (The control of the fifth wheel coupling load according to the slide is required.)
    The use of the vehicle you are now using is also possible. Please contact us for more information.

    Because the coupling is adjustable due to the slide mechanism,
    connection with various trailers is possible.
    One vehicle can be used with multiple trailers and
    this can contribute to the safety on rough or snow-coverd roads.

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