Fifth wheel couplings and mounting plates

Fifth wheel couplings are fitted to a tractor unit to connect it to the trailer.


Fifth wheel couplings are vehicle attaching parts that are subject to mandatory design approval and on which the highest safety requirements are placed. We can supply a suitable fifth wheel coupling for all applications, thus always guaranteeing a safe and secure link between the tractor and trailer.


When mounting, using, converting or exchanging our fifth wheel couplings, the vehicle manufacturer’s notes, JOST instructions for mounting and use, and the relevant national regulations must be observed. In Germany these are §§19, 20, 21, 27 of the “StVZO” Motor Vehicle Safety Standards.


The JSK 42 is available with a large selection of pedestals in all common heights and with all common hole patterns for plate and frame assembly. Depending on the model and height, it is possible to reduce the weight by 30 to 60 kg. This fifth-wheel coupling is also exceptionally easy to operate: the convenient handle enables you to release the lock and open the JSK 42 with one hand.

Design / features

JOST fifth wheel couplings fulfil the most stringent requirements in terms of safety, simple operation and ease of servicing. This results in the following benefits:


  • High level of operating reliability
  • Can be used in complicated loading conditions
  • Automatic latch arrangement
  • Only a visual inspection is required to ensure proper engagement
  • Protection against unauthorised opening is possible using a padlock
  • Various sensory solutions available

Ease of servicing

  • Stageless adjustment of the locking mechanism, resulting in lower wear
  • Easily replaceable plastic top plate liners
  • LubeTronic solutions available for easier lubrication
  • All wearing parts available in practical spare parts kits

    Simple operation

    • Long, easy-reach handle
    • The operator does not get dirty
    • The latch is released using a cable
    • Optional: One-handed operation with or without latch

    Product range

    • Couplings for imposed loads of 6-74 tonnes
    • Pressed metal or cast couplings
    • Various bearings and mounting heights
    • Weight-optimised frame assembly possible
    • Low-maintenance variants
    • System solutions such as Sensoric and LubeTronic available for all common fifth wheel couplings

    Range of application

    JOST‘s range includes the perfect fifth wheel coupling with the required imposed load for a wide range of applications – from lightweight distribution traffic to normal road transport; from site traffic to heavy-duty transport.

    Type designation

    The fifth wheel type plate is secured on the side of the coupling plate. When ordering spare parts, please quote the model designation and the serial number.

    Technical Specification

    The ECE directives comprise a catalogue of internationally agreed, consistent technical rules for motor vehicles and add-on parts for motor vehicles. The ECE mark is to be attached to every vehicle or add-on part in motor vehicles for which an ECE approval has been issued. The mark consists of a circle with the capital letter “E” and the ID number of the country issuing the approval. Accordingly, “E1” stands for Germany.

    Fifth wheel couplings and mounting plates are considered add-on parts for tractors used to connect tractors and trailers, making them vehicle connection parts that are subject to type approval.

    For JOST fifth wheel couplings and mounting plates, mainly ECE Directive R55 (Mechanical coupling components of combinations of vehicles) is of relevance. Another important directive for our system solution is ECE Directive R10 (Electromagnetic compatibility).

    The manufacturer’s specifications, the JOST mounting and operating instructions and the applicable national regulations need to be observed when mounting, operating, replacing or retrofitting fifth wheel couplings. In Germany, §§ 19, 20, 21 and 27 of the StVZO (German Road Traffic Licensing Regulation) apply.



    Explenatory notes for the following selection tables

    WA / Maintenance
    M = Manual lubrication
    Z = Prepared for connection to the central lubrication system on the tractor unit
    W = Low-maintenance with plastic top plate liner, lubrication only required on the lock jaw
    M, Z = Available either for manual lubrication or prepared for central lubrication
    LT 1P = Low-maintenance version with top plate liners and LubeTronic 1Point for automatic lock jaw lubrication
    LT 5P = LubeTronic 5Point central lubrication system
    EV = FlashTronic

    ZL / Handle length
    J = Long handle
    K = Short handle

    ST = Standard
    MAN = MAN
    VT = Volvo Truck
    MB = Mercedes-Benz
    RT = Renault Truck
    DAF = DAF
    IV = Iveco
    SC = Scania
    DW = Daewoo
    FO = Ford