Product Overview
Build your own heavy-duty 6’10” × 20′ tandem-axle car hauler and equipment trailer with these professionally engineered trailer plans. Designed to be built in either a 14,000 lb or 16,000 lb Gross Vehicle Weight Rating (GVWR) configuration, these plans are ideal for hauling cars, trucks, Jeeps, UTVs, tractors, skid steers, compact construction equipment, and a wide variety of commercial equipment.
Engineered around heavy-duty tandem leaf-spring axles, the trailer can be configured using 7,000 lb straight axles, 7,000 lb 4″ drop axles (14K configuration), or 8,000 lb straight axles (16K configuration). The rugged welded steel I-beam frame provides exceptional strength while maintaining a low deck height for easier loading. Multiple engineered configuration options are included throughout the plans, allowing you to build the trailer that best fits your hauling needs.
Included options include multiple deck styles, removable or fixed fenders, loading ramps, tie-down anchor locations, front rail options, winch mounting, tongue accessories, and much more.
Complete Plan Package Includes
Plan Model: Mu720DS14C (7×20-140ds-cctrailer)
- 41 pages of detailed engineering drawings
- 29 pages of instructions, materials lists, options, engineering considerations, and illustrated building guidance
- Material Cut List
- Purchased Components List (BOM)
- Trailer Frame, Tongue, Axle, and Suspension Details
- Multiple Deck, Fender, and Ramp Configurations
- Steel Loading Ramp Designs and Slide-Under Storage Options
- Tie-Down Anchor, Front Rail, and Winch Options
- Toolbox, Tongue Jack, and Rear Support Options
- Illustrated Construction Techniques and Practical Building Guidance
Trailer components, steel, axles, suspension, brakes, wheels, tires, decking, ramps, winches, electrical components, and fabrication materials are NOT included with the plans. Matching Trailer Parts Kits are available separately.
Available Plan Formats
Instant PDF Download
Download your plans immediately after checkout and begin building right away. The downloadable ZIP file contains the complete engineering drawing package, instructions, materials information, and supporting documents.
Printed Paper Copy
Prefer working from paper in the shop? Choose our printed paper 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
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.
Heavy-Duty I-Beam Construction
The trailer is built around a heavy-duty welded steel I-beam frame engineered to provide exceptional strength, rigidity, and long-term durability for demanding hauling applications. Structural I-beams are combined with welded C-channel, angle, and other steel components to create a durable fixed-deck trailer that can be built in either a 14,000 lb or 16,000 lb Gross Vehicle Weight Rating (GVWR) configuration.
The plans include multiple axle configurations to match your intended application. Builders may choose 7,000 lb straight axles, 7,000 lb 4″ drop axles for the 14,000 lb configuration, or 8,000 lb straight axles for the 16,000 lb configuration. The I-beam design provides exceptional structural strength while maintaining a low deck height for easier loading of vehicles and equipment.
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
These plans include numerous engineered configuration options, allowing you to build the trailer that best fits your hauling needs.
- 14,000 lb or 16,000 lb GVWR Configuration
- 7,000 lb Straight, 7,000 lb 4″ Drop, or 8,000 lb Straight Axle Options
- Double-Eye or Slipper Leaf Spring Suspension
- Solid, Plank, Split, or Full Metal Deck
- Wood or Metal Decking
- Removable, Welded, or Bolted Fenders
- Multiple Loading Ramp Lengths, Widths, Materials, and Capacities
- Hidden Slide-Under Ramp Storage
- Multiple Tie-Down Anchor Locations
- Optional Front Rail (Short or Tall)
- Fixed or Removable Winch Mount
- Tongue-Mounted Toolbox
- Multiple Tongue Jack Options
- Rear Support Options
Thinking about customizing these trailer plans? Read When Safe to Customize the Plans before making modifications to the original engineered design.
Matching Trailer Parts Kits
Complete your build with our matching 6’10” × 20′ Car Hauler / Equipment Trailer Parts Kits. Choose either our 14,000 lb or 16,000 lb kit, each designed specifically for these plans to simplify your build by grouping compatible major trailer components into one convenient package.
View the Matching 14K Trailer Parts Kit
View the Matching 16K Trailer Parts Kit
Professionally Engineered Plans
These trailer plans were professionally engineered by Synthesis Engineering Services. The engineering package evaluates structural members, frame geometry, suspension placement, connection points, and load paths to provide a strong, durable 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, brake system installation, and 12-volt trailer wiring is recommended before beginning the project.
Understanding Trailer Weight, GVWR, and Payload
These plans can be built in either a 14,000 lb or 16,000 lb Gross Vehicle Weight Rating (GVWR) configuration. GVWR represents the maximum allowable weight of the completed trailer and everything loaded on it, including cargo, equipment, accessories, and the trailer itself.
The base 14,000 lb trailer weighs approximately 2,200+ lbs before decking and optional equipment. A typical completed trailer with wood decking, ramps, tie-downs, and common accessories weighs approximately 3,000 lbs, although final weight will vary depending on your material selection, decking, ramps, tie-down options, toolbox, winch, battery, tongue accessories, jack configuration, wheels, tires, axles, and other builder-selected options.
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?
Your purchase includes complete professionally engineered trailer plans consisting of 41 pages of engineering drawings and 29 pages of instructions, material lists, configuration options, engineering considerations, and illustrated building guidance. The plans are available as either an instant PDF download or a printed paper copy.
Can I build this trailer as either a 14,000 lb or 16,000 lb GVWR trailer?
Yes. These plans include the information required to build either a 14,000 lb or 16,000 lb Gross Vehicle Weight Rating (GVWR) trailer. Material specifications and component requirements for each configuration are included throughout the plans.
What axle configurations are these plans designed for?
The plans support multiple heavy-duty axle configurations, including 7,000 lb straight axles, 7,000 lb 4″ drop axles for the 14,000 lb configuration, and 8,000 lb straight axles for the 16,000 lb configuration. Builders may also choose either double-eye or slipper leaf spring suspension.
Can I customize these trailer plans?
Yes. The plans include numerous engineered options, including multiple deck styles, removable or fixed fenders, loading ramp designs, tie-down locations, front rail options, winch mounting, toolbox configurations, tongue accessories, and more. Structural modifications should always be carefully evaluated before construction.
Are these plans available as a PDF download or printed paper copy?
Yes. Choose an instant PDF download available immediately after checkout or a printed paper copy shipped flat for convenient workshop use. Both versions contain the same engineering information.
What builder experience is recommended?
These plans are intended for builders with intermediate welding and metal fabrication experience. Familiarity with trailer construction, suspension installation, brake system installation, and 12-volt trailer wiring is recommended.
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, hydraulic systems, lighting, and thousands of trailer parts backed by knowledgeable customer support before and after the sale.
Whether you’re building your first 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











