8.5′ x 16′ Deck Over Trailer Plans – 7,000 lb GVWR

Product Overview

Build your own 8’6″ × 16′ deck-over trailer with the professionally engineered MDo816DS70 Deck-Over Trailer Plans. Designed for a maximum 7,000 lb Gross Vehicle Weight Rating (GVWR), this heavy-duty tandem-axle trailer provides a full-width deck and numerous builder-selectable options, making it ideal for hauling tractors, equipment, UTVs, building materials, pallets, and oversized cargo.

The finished trailer features a nominal 8’6″ × 16′ deck with an actual deck length of approximately 16′ 3½”, an overall width of approximately 102″ including the rub rails, and an overall length of approximately 21 feet including the tongue. Built around tandem 3,500 lb leaf-spring axles with an equalizer suspension, the design provides excellent stability while maximizing usable deck space for a wide variety of hauling applications.

Engineered using welded rectangular steel tube main frame rails, the trailer is designed to deliver excellent structural strength without unnecessary weight. Builders can customize the trailer with multiple ramp configurations, deck materials, side options, tie-down arrangements, rub rails, front rails, tool storage, and other engineered options to create a trailer tailored to their specific needs.

---

Complete Plan Package Includes

Plan Model: MDo816DS70 (8×16-70ds-dtrailer)

• 35 pages of detailed engineering drawings
• 20 pages of illustrated instructions, material lists, purchased components list (BOM), engineering considerations, and building guidance
• Complete Material Cut List
• Purchased Components List (BOM)
• Trailer Frame Construction Details
• Axle, Suspension, and Brake Installation Information
• Ramp Design and Capacity Selection Information
• Deck Configuration Options
• Side Configuration Options
• Engineering Considerations and Construction Notes
• CAD files for optional laser, plasma, or waterjet-cut components
• Illustrated construction techniques and practical building guidance

Trailer components, steel, running gear, wheels, tires, brakes, coupler, lighting, electrical components, hardware, and fabrication materials are NOT included with the plans. Complete your build with our matching 7K Deck-Over Trailer Parts Kit, designed specifically for these plans to simplify your build by grouping compatible major trailer components into one convenient package.

---

Available Plan Formats

Instant PDF Download

Download your plans immediately after checkout and begin preparing your build right away. The downloadable ZIP file contains the complete engineering drawing package, illustrated instructions, material information, purchased components list (BOM), engineering considerations, CAD files for optional components, and supporting documents.

Professionally Printed Paper Plans

Prefer working from paper in the shop? Choose our professionally printed plan package.

• Engineering drawings printed on 11″ × 17″ sheets for improved readability
• Instructions printed on standard 8.5″ × 11″ pages
• Shipped flat — never rolled or folded
• Free shipping within the lower 48 states

CAD Cut Files: Customers who purchase the Printed Paper Copy can contact Johnson Trailer Parts after purchase to receive the included CAD cut files electronically at no additional charge.

Important: Printed engineering drawings are provided for reference during construction and should never be scaled for dimensions. Always use the dimensions and measurements provided within the plans.

---

Deck-Over Trailer Design

The MDo816DS70 is engineered to provide the strength and versatility expected from a full-width deck-over trailer while maintaining a practical 7,000 lb Gross Vehicle Weight Rating (GVWR). Built around tandem 3,500 lb leaf-spring axles and a welded rectangular steel tube main frame, the design provides excellent structural rigidity, long-term durability, and dependable performance for hauling equipment, vehicles, tractors, pallets, building materials, and other oversized loads.

Unlike conventional equipment trailers with fenders between the wheels, the deck-over design provides a full-width loading surface across the entire trailer. This allows wider cargo to be loaded more easily while maximizing usable deck space. Builders can further customize the trailer using the numerous engineered options included throughout the plans to create a trailer that best fits their intended application.

Proper fabrication, welding, material selection, component installation, and load placement remain essential to the safety, durability, and long-term performance of the completed trailer.

---

Customizable Trailer Options

• Multiple Deck Material Options
• Wood or Steel Deck Configurations
• Slide-In Loading Ramp Options
• Multiple Ramp Length and Capacity Options
• Permanent or Removable Side Configurations
• Stake Pocket Options
• Rub Rail and Tie-Down Configurations
• Raised Front Rail Options
• Tongue Tray Option
• Toolbox Mounting Options
• Spare Tire Mount Option
• Multiple Tie-Down Anchor Locations

Thinking about customizing these trailer plans? Read When Safe to Customize the Plans before making modifications to the original engineered design.

---

Matching Trailer Parts Kit

Complete your build with our matching 7K Deck-Over Trailer Parts Kit. Designed specifically for the MDo816DS70 trailer plans, the kit simplifies your build by grouping compatible major trailer components into one convenient package.

View the Matching 7K Deck-Over Trailer Parts Kit

---

Professionally Engineered Plans

These trailer plans were professionally engineered by Synthesis Engineering Services. The engineering package evaluates the trailer frame, crossmembers, tongue structure, suspension placement, ramp attachment points, connection details, and load paths to provide a strong, durable, and reliable deck-over trailer design.

As with any trailer project, proper material selection, fabrication quality, welding, assembly, maintenance, loading practices, and compliance with applicable laws remain the responsibility of the builder.

---

Recommended Builder Experience

Intermediate. This project is best suited for builders with welding and metal fabrication experience. Familiarity with trailer construction, suspension installation, axle alignment, brake installation, and 12-volt trailer wiring is recommended before beginning the project.

---

Understanding Trailer Weight, GVWR, and Payload

These plans are engineered for a maximum 7,000 lb Gross Vehicle Weight Rating (GVWR). GVWR represents the maximum allowable weight of the completed trailer and everything loaded on it, including cargo, tools, accessories, and the trailer itself.

The completed trailer weight varies depending on the materials and options selected during construction. Estimated base trailer weight is approximately 1,600 lbs before decking, ramps, sides, and optional accessories. Optional equipment such as heavier decking, taller sides, longer ramps, toolboxes, spare tires, and other builder-selected components will affect the final trailer weight and available payload.

Available payload can be estimated using the following formula:

GVWR − Actual Completed Trailer Weight = Available Payload

For the most accurate payload calculation, weigh the completed trailer on a certified vehicle scale after construction. Always stay within the ratings of the completed trailer, axles, suspension, tires, wheels, coupler, hitch, and all other installed components.

---

Frequently Asked Questions

What is included with these trailer plans?

The plans include professionally engineered drawings, illustrated step-by-step instructions, material cut lists, purchased components lists (BOM), engineering considerations, CAD files for optional laser, plasma, or waterjet-cut components, and practical construction guidance to help you build the trailer with confidence.

What axle configuration are these plans designed for?

These plans are engineered for tandem 3,500 lb leaf-spring axles using a double-eye suspension with an equalizer. Slipper spring suspension may also be used. The design is not intended for independent torsion axles.

Can I customize these trailer plans?

Yes. The plans include numerous engineered options including deck materials, side configurations, loading ramps, tie-down locations, rub rails, stake pockets, front rails, tongue tray options, and more. Structural modifications beyond the engineered options should be carefully evaluated before construction.

Are the CAD cut files included with both PDF and printed plans?

Yes. CAD cut files are included with the downloadable plans. Customers who purchase the printed paper plans can simply contact us and we will provide the CAD files electronically.

Are these plans available as a PDF download or printed copy?

Yes. The plans are available as an instant PDF download or as printed paper plans shipped flat within the lower 48 states.

What builder experience is recommended?

Intermediate. Welding and fabrication experience is recommended, along with familiarity with trailer construction, axle installation, suspension setup, brake installation, and 12-volt trailer wiring.

---

Why Choose Johnson Trailer Parts?

Johnson Trailer Parts has been helping customers build and maintain trailers since 2000. We provide professionally engineered trailer plans, matching trailer parts kits, trailer axles, suspension components, lighting, brakes, couplers, and thousands of trailer parts backed by knowledgeable customer support before and after the sale.

Whether you’re building your first deck-over trailer or adding another trailer to your fleet, we’re committed to providing quality products, dependable service, and the technical support you need to complete your project with confidence.

---

Questions?

Need help selecting the right trailer plans or matching trailer parts kit? Our team is happy to help.

Johnson Trailer Parts
Call or Text: (602) 292-9690
Email: sales@johnsontrailerparts.com