Fifth Wheels

JSK37U  Series

JSK37U Series Fifth Wheels Overview

The JSK37U series is JOST’s flagship line of cast ductile iron fifth wheels that is a standard specification option at every OEM. This series features the original locking mechanism that all other JOST fifth wheels are based on and sets the industry standard for fifth-wheel construction and functionality. Designed with safety and operator efficiency in mind, the features included in the JSK37U line are included in all other JOST fifth wheel products.

  • Available with a cushion ring or steel wear ring
  • Infinite adjustment
  • 3-Point Locking System
  • Anti-high coupling lugs
  • Requires only 60lbs of force to open
  • Can be rebuilt on truck in 30 minutes without removing the top plate

Key Features & Benefits

JSK37U  Series

Replaceable Cushion Ring

A replaceable cushion ring reduces the lifetime cost of ownership. JOST parts across product lines ensure affordable, consistent product availability.

JOST Locking Mechanism

JOST’s signature 3-point locking system features three locks with just four moving parts to ensure ultimate safety & simplicity.

Anti-High Coupling Lugs

Innovative anti-high coupling lugs prevent drivers from high coupling by either guiding the kingpin into the jaws or pushing it up and over. This allows for a clear indication when the fifth wheel is properly coupled.

Download the jost fifth wheel catalog

A comprehensive look into each of the JOST fifth wheel products.

Parts, Assemblies & Specs

JSK37U  Series

JOST’s JSK37U Series is available in standard, air release, and low lube top plate options, all of which seamlessly pair with a range of mount styles to suit any commercial trucking application. The JSK37U series has a maximum vertical rating of 50,000 lbs and a maximum horizontal rating of 150,000 lbs.

All JSK37U Series literature is available below:

Top Plates

Mounting Brackets

Bracket Exchange Program: The JOST Bracket Exchange Program offers additional flexibility. JOST will send a new bracket to you, in return of your current bracket.

Please call Customer Service at 800-253-5105 to learn more.

Replacement Parts

Bracket Pin Replacement - All 37 Series Wheels
Lock Jaw & Cushion Ring Replacement
Inspection & Maintenance Guidelines

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Warranty Statements

Claims should be filed with JOST or any authorized sales or service outlet within 60 days of product failure.

roi calculator

Measure and compare the total cost of ownership of a JOST fifth wheel vs. competitor fifth wheels.

JOST International is a world market leader for the commercial trucking industry. As a pioneer of efficient, safe, and innovative systems for trucks and trailers, we proudly supply fifth wheel couplings, trailer landing gear, kingpins, turntables, and more.

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