Johnson Trailer Parts 8.5 x 20 Deck Over Trailer Plans, 10,400 lb Capacity, DIY Blueprints, Step-by-Step Instructions, MDO820DS104

Johnson Trailer Parts 8.5 x 20 Deck Over Trailer Plans, MDO820DS104 Trailer BlueprintsBuild your own heavy-duty 8' 6" x 20' deck over trailer with these detailed MDO820DS104 blueprints. Designed for a 10,400 lb capacity tandem axle trailer, this plan set includes step-by-step instructions, steel cut list, material guidance, and fabrication details for a full-width deck-over design. Plans engineered by Synthesis Engineering Services, Inc. for a precise, heavy-duty trailer design.Specifications:Model: MDO820DS104Bed Size: 8' 6" x 20'Max Capacity: 10,400 lbsTrailer Type: Deck Over TrailerFrame: Welded steel constructionThis plan package includes 39 pages of drawings plus 20 pages of instructions. Pages ship flat for easier use on a standard workbench and are easier to handle in the shop than rolled plans while still providing large, detailed drawings across multiple pages.Designed with multiple build options, these plans can be adapted to suit a range of trailer uses. Optional features include ramp configurations and ramp length options, raised front stop rail, deck choices, stake pockets, side rub rails, tongue storage tray, adjustable hitch setup, and other practical trailer details. Johnson Trailer Parts also offers a matching trailer parts kit for this plan. Ideal for Do-It-Yourselfers, Builders, and Shop Classes.Note: These blueprints show how to build the trailer and install major components. They do not include physical trailer parts or instructions for manufacturing purchased components such as axles or other trailer hardware.Legal Notice: 2026 Johnson Trailer Parts. All rights reserved. These plans are licensed for personal use only. Copying, scanning, digital sharing, distribution, or reselling of this publication is strictly prohibited under U.S. copyright law.

• Deck Over Trailer Plans: Detailed engineered blueprints with step-by-step instructions for building an 8.5 x 20 deck over trailer from the ground up. Includes steel cut list, material guidance, and fabrication details for a full-width trailer design
• 10,400 lb Capacity Design: Engineered for a heavy-duty tandem axle configuration with a 10,400 lb maximum capacity. Ideal for hauling equipment, vehicles, materials, and general-purpose cargo
• Detailed Drawings Shipped Flat: Includes 39 pages of drawings plus 20 pages of instructions. Ships flat for easier use on a standard workbench without the frustration of rolled-up plans
• Component Installation & Mounting: Includes layout and mounting guidance for standard trailer axles and related trailer components. These plans show how to build the trailer and install major components, but do not include instructions for manufacturing axles or other trailer parts
• Customizable Build Options: Includes multiple options such as ramp configurations, raised front design, deck choices, stake pockets, side rub rails, tongue storage tray, and adjustable hitch setup to help tailor the trailer to your build