Why design matters

When choosing a truck body or trailer, we realize that you have a lot of choices. You can choose any number of truck beds or trailers from many manufacturer catalogs. At K&K Manufacturing, we will not offer you a catalog. We choose to offer you a free consultation to better understand your business and your unique requirements. With this approach, we are able to custom design and fabricate solutions that will help you to increase efficiency, boost productivity, and raise profitability.

The Importance of Chassis and Cab Data for Upfitting

Our ultimate goal as a truck equipment manufacturer and upfitter is to provide our customers with direction that allows them to select a chassis that is ideal for what it needs to do. A chassis that is too light for the job will be overloaded, resulting in excessive maintenance costs. One that is too large costs more to buy and more to fuel. The wrong wheelbase can result in poor handling and weight can be distributed poorly.

We walk our customers through this process by finding out some basic details before we enter the design phase:

  • Establish what the completed truck will be required to do, where it will operate, how it will be driven, how many people it needs to seat, and the desired life cycle
  • Review special equipment requirements
  • Calculate the cab to axle length needed to accommodate the selected body
  • Calculate payload requirements

We then analyze the required payload and weight distribution requirements, make sure the chosen frame is strong enough to perform the requirements stated, and where applicable make powertrain recommendations.

Planning out the cab and chassis details of our builds in advance, and making sure that those details directly relate to the usability and longevity of the project, brings the best possible product to our customers, every time.

See for yourself - Contact us today for a free consultation.

Payload Data

Weight is important—not only the total weight that the truck must carry, but also how it is distributed among the axles. A truck that overloads an axle violates weight laws—even if the truck is below it’s gross vehicle weight rating. We calculate a preliminary weight distribution analysis to make sure that the truck we’ve planned distributes the load properly by identifying the weight and dimensional data of the chassis being considered, its wheelbase dimensions, back of cab to rear axel dimension, front axle to back of cab dimension, distance between the cab to body, passenger seating data, payload requirements, and the amount of weight the chassis places on front and rear axles as produced at the factory. We plug these numbers into a mathematical formula to ensure the truck has a sufficient payload rating to meet the customer’s needs.


The chassis comes from the manufacturer certified for compliance with applicable motor vehicle standards. We stay within OEM and DOT guidelines when designing our vehicles. The body builders guide published by the chassis manufacturer is an additional reference source that we follow.

These documents specify the OEM’s requirements for completing the vehicle with a pass-through certification. They define allowable and prohibited modifications, and provide guidelines and recommendations for mounting second-unit components on a chassis.

By following the above referenced guidelines, the final manufactured vehicle will comply with all of the requirements established by the chassis OEM, and the original certification will pass-through to the completed vehicle.

If the modification to the vehicle falls beyond OEM certification guidelines, we will certify that the vehicle, as completed, complies with all applicable federal standards by proving that the modified vehicle still conforms to applicable standards and that no safety devices have been rendered inoperative.

State weight and dimensional criteria, state and federal operating restrictions, Federal Motor Carrier Safety Administration requirements, OSHA standards, and an array of other guidelines are verified during this certification process.

Commercial Drivers License Requirements

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