3500 lb Tandem Axle Kit (7K Capacity) 89/74 – Master Kit (614T/616T)

SKU # 35TA8974545MK

Build a complete 6′ x 14′ or 6′ x 16′ tandem axle utility trailer with this comprehensive 7,000 lb Master Kit. Designed around two 3,500 lb axles with an 89″ hub face / 74″ spring center, this package combines an idler axle and electric brake axle with the trailer blueprints, suspension, tires and wheels, tandem fenders, coupler, jack, lighting, wiring, breakaway system, gate hardware, tie-down points, and other essential fabrication components.

This Master Kit is a major step beyond a basic rolling kit, providing the core running gear along with the electrical, braking, body, and safety hardware needed for a more complete tandem axle trailer build.

What’s Included

Blueprints

• (1) Utility Trailer 6′ x 14′ / 6′ x 16′ Tandem Axle Flat / Dove Tail Blueprint Package

Axles & Suspension

• (1) 3,500 lb Idler Axle – 89″ Hub Face / 74″ Spring Center
• (1) 3,500 lb Electric Brake Axle – 89″ Hub Face / 74″ Spring Center
• Double Eye Leaf Springs
• U-Bolt Mounting Hardware
• (1) Tandem Axle Hanger Kit

Tires, Wheels & Fenders

• (4) ST205/75R15 Trailer Tires & Wheels – 5 Lug
• (20) Lug Nuts
• (2) Smooth Rolled Tandem Axle Fenders
• (2) Tandem Fender Backs
• (2) Fender Steps with Holes – LH/RH
• (2) Fender Steps without Holes – LH/RH

Coupler, Jack & Safety Equipment

• (1) 2″ Trailer Coupler
• (1) 5,000 lb Trailer Jack
• (1) Jack Plate
• (1) Jack Foot Plate
• (2) 5/16″ x 30″ Grade 70 Safety Chains with 7,600 lb S-Hooks
• (2) Chain Loops
• (1) Breakaway Kit

Frame & Fabrication Components

• (1) Cover Plate
• (2) Joining Plates
• (2) Indicator Tabs

Trailer Wiring & Lighting

• (1) 7-Way Trailer Plug
• (50′) Color-Coded Trailer Wire
• (1) 12V LED Left / Right Tail Light Set
• (1) 3-Light LED Identification Light Bar
• (4) 3/4″ Amber LED Side Marker Lights
• (1) License Plate Bracket
• (2) Light Brackets

Gate & Latch Hardware

• (6) Inner Gate Hinges
• (2) Outer Gate Hinges
• (2) Tailgate Latches – Left & Right
• (2) U-Latches

Cargo & Visibility Components

• (4) Tie-Down Rings
• (4) 2″ x 12″ Conspicuity Tape Strips
• (2) 1″ x 12″ Conspicuity Tape Strips

Kit Specifications

Features & Benefits

Complete Tandem Axle Trailer Build Package

This Master Kit combines the major mechanical, braking, electrical, safety, and body components needed for a 6-foot-wide tandem axle utility trailer build.

7,000 lb Combined Axle Capacity

The tandem setup uses two 3,500 lb axles for a combined axle capacity of 7,000 lbs, making it a strong foundation for larger utility, landscape, and equipment trailer applications.

Idler & Electric Brake Axle Combination

The kit includes one idler axle and one electric brake axle, providing braking capability while keeping the overall tandem setup straightforward and cost-effective.

89/74 Axle Configuration

Both axles feature an 89-inch hub face and 74-inch spring center, making the critical axle dimensions easy to confirm before fabrication.

Complete Tandem Suspension System

The axles, leaf springs, U-bolt hardware, and tandem hanger kit provide the core suspension components needed to mount and support the complete tandem axle assembly.

Four ST205/75R15 Tires & Wheels

Four ST205/75R15 5-lug trailer tire and wheel assemblies are included along with the required lug nuts, providing the complete wheel package for the tandem setup.

Tandem Fenders & Fender Steps

Smooth rolled tandem fenders, fender backs, and both left- and right-hand fender steps are included to help complete the trailer body and provide a finished, functional appearance.

Electric Brake Wiring & Breakaway System

A 7-way plug, 50 feet of color-coded wiring, electric brake axle, and breakaway kit provide the primary electrical components needed for the trailer braking system.

Complete LED Lighting Package

The kit includes LED tail lights, four amber side marker lights, a three-light identification bar, license plate bracket, and light mounting brackets for a complete trailer lighting setup.

Gate & Latch Hardware

Inner and outer gate hinges, tailgate latches, U-latches, and indicator tabs provide the primary hardware needed to fabricate and secure the trailer gate.

Cargo & Safety Components

Four tie-down rings provide convenient cargo securement points, while Grade 70 safety chains, chain loops, conspicuity tape, and the breakaway system add important towing and safety components.

Common Applications

• 6′ x 14′ Utility Trailers
• 6′ x 16′ Utility Trailers
• Tandem Axle Landscape Trailers
• Equipment Trailers
• ATV & UTV Trailers
• Lawn Care Trailers
• Farm & Property Trailers
• General-Purpose Cargo Trailers
• Dove Tail Utility Trailers
• Flat Deck Utility Trailers
• DIY Trailer Builds
• Custom Trailer Fabrication

Why Choose a Master Kit?

Building a tandem axle trailer from scratch requires dozens of separate parts across the running gear, braking, electrical, body, and safety systems. This Master Kit simplifies the process by combining the blueprints, axles, suspension, wheels, fenders, towing hardware, wiring, lighting, brake components, gate hardware, tie-downs, and fabrication pieces into one coordinated package.

That means fewer individual components to source and a clearer path from raw material to a completed tandem axle trailer.

Important Fitment & Build Information

Please verify all measurements, capacities, and component requirements before beginning your trailer build.

• Trailer Size: 6′ x 14′ / 6′ x 16′
• Hub Face: 89″
• Spring Center: 74″
• Individual Axle Capacity: 3,500 lbs
• Combined Axle Capacity: 7,000 lbs
• Axle Setup: 1 Idler + 1 Electric Brake
• Tire Size: ST205/75R15
• Coupler Size: 2″
• Electrical Connection: 7-Way
• Breakaway Kit: Included

The 7,000 lb combined axle rating does not automatically mean the completed trailer is rated for 7,000 lbs of payload. Final trailer capacity and legal GVWR depend on the completed trailer design and the lowest-rated component in the assembly, including the frame, suspension, tires, wheels, coupler, brakes, and other hardware.

Need help with your build or selecting the correct tandem axle kit? Contact Highway 96 Trailers and our team can help you choose the right setup for your project.