Rockwell American Tandem 7,000 lb Electric Brake Trailer Axle Kits – Slipper Springs

Rockwell American Tandem 7,000 lb Electric Brake Trailer Axle Kits – Slipper Springs

Build, repair, or upgrade your trailer with genuine Rockwell American Tandem 7,000 lb Electric Brake Trailer Axle Kits with Slipper Springs. Designed for equipment trailers, car haulers, dump trailers, gooseneck trailers, flatbed trailers, enclosed cargo trailers, and other heavy-duty tandem applications, these complete running gear packages deliver dependable braking, heavy-duty slipper spring suspension, and long-lasting performance.

Each kit includes (2) genuine Rockwell American 7,000 lb electric brake trailer axles for a combined 14,000 lb Gross Axle Weight Rating (GAWR). Choose from Axle Only, Suspension Kit, Build Kit, or Running Gear Kit configurations, with multiple Hub Face (HF) and Spring Center (SC) sizes to match your trailer.

Rockwell American trailer axles are part of the Dexter family of trailer axle brands and feature 12″ × 2″ electric brakes, Posi-Lube® greaseable spindles, and heavy-duty powder-coated axle beams. Suspension, Build, and Running Gear Kits include slipper springs, while Build and Running Gear Kits also include the tandem slipper spring hanger kit. Running Gear Kits add 16″ 8-lug trailer wheels with ST235/80R16 radial trailer tires for a complete trailer running gear solution.

Made in America. Free Shipping in the Lower 48 States.

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Compare Kit Options

Select the tandem trailer axle package that best fits your trailer repair, running gear replacement, or new trailer build.

← Swipe left/right to compare all kit options →

Axle Only: Includes (2) Rockwell American 7,000 lb electric brake trailer axles with hubs, drums, electric brakes, and Posi-Lube® greaseable spindles.

Suspension Kit: Includes (2) Rockwell American 7,000 lb electric brake trailer axles, (4) Slipper springs, and (2) U-bolt kits.

Build Kit: Includes (2) Rockwell American 7,000 lb electric brake trailer axles, (4) Slipper springs, (2) U-bolt kits, and (1) Tandem slipper spring hanger kit.

Running Gear Kit: Includes (2) Rockwell American 7,000 lb electric brake trailer axles, (4) Slipper springs, (2) U-bolt kits, (1) Tandem slipper spring hanger kit, (4) 16″ 8-lug trailer wheels, and (4) ST235/80R16 radial trailer tires.

Axle Only and Suspension Kit configurations are ideal for trailer repairs and suspension upgrades, while Build Kit and Running Gear Kit configurations provide complete solutions for new trailer construction, trailer rebuilds, and full running gear replacement.

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Choose Your Axle Size (Hub Face / Spring Center)

All available Hub Face (HF) and Spring Center (SC) sizes are manufactured using the same premium Rockwell American components. Simply select the dimensions that match your trailer frame and suspension for proper axle alignment, wheel positioning, tire clearance, and safe towing performance.

• Hub Face (HF): Measured from the wheel mounting surface on one hub to the wheel mounting surface on the opposite hub.
• Spring Center (SC): Measured from the center of one spring seat to the center of the opposite spring seat.

Correct Hub Face and Spring Center measurements help ensure proper tandem axle spacing, suspension alignment, tire clearance, fender clearance, and overall trailer fitment.

Not sure which axle size you need? Read our How to Measure a Trailer Axle Guide before ordering, or contact us and we’ll help verify your measurements.

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Why Choose Rockwell American?

• Made in America: Genuine Rockwell American trailer axle components manufactured in the USA and backed by the Dexter family of trailer axle brands.
• 14,000 lb Combined Axle Capacity: Two 7,000 lb trailer axles provide a combined 14,000 lb Gross Axle Weight Rating (GAWR) for heavy-duty tandem trailer applications.
• Electric Brakes on Both Axles: Four pre-installed 12″ × 2″ electric brake assemblies provide dependable stopping power, balanced braking, and improved towing control.
• Heavy-Duty Slipper Spring Suspension: Slipper springs are designed for durability, dependable load support, and long service life in demanding trailer applications.
• Posi-Lube® Spindles: Integrated grease fittings simplify routine bearing lubrication without removing the hubs.
• Heavy-Duty 3″ Axle Tubes: High-strength cambered axle beams help promote proper wheel alignment, stable towing, and even tire wear under load.
• Durable Powder-Coated Finish: Helps protect the axle beams against corrosion, weather exposure, road debris, and everyday trailer use.
• Complete Trailer Running Gear Packages: Available from Axle Only through complete Running Gear Kits with suspension components, wheels, and tires.

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Key Features

• (2) Rockwell American 7,000 lb electric brake trailer axles
• 14,000 lb combined Gross Axle Weight Rating (GAWR)
• Electric brakes on both axles
• 12″ × 2″ electric brake assemblies
• 8 on 6.5″ wheel bolt pattern
• #42 Posi-Lube® greaseable spindles
• Heavy-duty 3″ round cambered axle tubes
• Powder-coated axle beam finish
• Slipper springs
• Tandem slipper spring hanger kit available with Build Kit and Running Gear Kit configurations
• Multiple Hub Face (HF) and Spring Center (SC) sizes
• Four available kit configurations
• Optional 16″ 8-lug trailer wheels with ST235/80R16 radial trailer tires

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Posi-Lube® Spindle System

Every Rockwell American 7,000 lb trailer axle included in these tandem axle kits features genuine Posi-Lube® greaseable spindles, making routine bearing maintenance quicker and more convenient than traditional spindle designs.

Grease is delivered through the center of each spindle and directed into the hub assembly, helping distribute fresh grease through the bearings while pushing older grease outward. This allows routine bearing lubrication to be completed without removing the hub-and-drum assemblies.

When serviced correctly and according to the manufacturer’s maintenance recommendations, Posi-Lube® spindles can help reduce service time, protect wheel bearings, and support dependable trailer operation.

Posi-Lube® systems are intended to simplify routine lubrication but do not eliminate the need for regular bearing, seal, brake, and hub inspections.

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Common Applications

• Equipment Trailers
• Car Haulers
• Dump Trailers
• Gooseneck Trailers
• Flatbed Trailers
• Cargo Trailers
• Enclosed Trailers
• Utility Trailers
• Construction Trailers
• Farm and Ranch Trailers
• Skid Steer Trailers
• Custom Trailer Builds

These Rockwell American Tandem 7,000 lb Electric Brake Trailer Axle Kits with Slipper Springs are ideal for tandem axle replacement, trailer suspension upgrades, complete running gear replacement, and new heavy-duty trailer construction.

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Fitment & Capacity Notes

• Verify the required Hub Face (HF) and Spring Center (SC) measurements before ordering.
• Both axles must use matching Hub Face, Spring Center, capacity, brake, and suspension specifications.
• Confirm the selected 8 on 6.5″ bolt pattern matches your existing or planned trailer wheels.
• Verify slipper spring length, spring capacity, hanger spacing, and suspension configuration before installation.
• Check for adequate tire, wheel, fender, frame, brake wiring, and suspension clearance throughout the full range of suspension travel.
• Electric brakes require a compatible in-cab brake controller and properly functioning trailer brake wiring.
• A correctly installed and operational trailer breakaway system may be required and should be used where applicable.
• Brake assemblies on both axles must be wired correctly and adjusted according to the brake manufacturer’s recommendations.
• The combined 14,000 lb GAWR represents the maximum rated capacity of the two axles and does not determine the trailer’s overall GVWR or payload capacity.
• Overall trailer capacity is limited by the lowest-rated component in the complete trailer system, including the frame, coupler, suspension, wheels, tires, hubs, brakes, safety equipment, and tow vehicle.
• Do not assume that installing two 7,000 lb axles automatically gives an existing trailer a 14,000 lb GVWR.
• Verify wheel and tire load ratings before loading the trailer.
• Hanger installation, axle alignment, suspension setup, and frame welding should be completed by a qualified trailer fabricator when applicable.
• Axles should be installed square and parallel to each other to promote proper tracking and reduce premature tire wear.
• Follow the wheel manufacturer’s recommended lug nut torque specifications and tightening sequence.
• Recheck lug nut torque after the initial installation and again after the first period of towing.
• Inspect the brakes, wiring, breakaway system, suspension hardware, bearings, seals, wheels, tires, and lug nuts before placing the trailer into service.

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Frequently Asked Questions

What is included with each kit configuration?

Axle Only includes (2) genuine Rockwell American 7,000 lb electric brake trailer axles with pre-installed hub-and-drum assemblies and Posi-Lube® greaseable spindles.

Suspension Kit includes everything in the Axle Only configuration plus (4) genuine Rockwell American 1203T3 slipper springs and (2) U-bolt kits.

Build Kit includes everything in the Suspension Kit plus a complete Rockwell American APT6SE tandem slipper spring hanger kit for new trailer construction or complete suspension replacement.

Running Gear Kit includes everything in the Build Kit plus (4) 16″ 8-lug trailer wheels and (4) ST235/80R16 radial trailer tires for a nearly complete tandem trailer running gear solution.

How do I measure my trailer axle?

The two primary measurements are Hub Face (HF) and Spring Center (SC). Hub Face is measured from the wheel mounting surface on one hub to the wheel mounting surface on the opposite hub. Spring Center is measured from the center of one spring seat to the center of the other.

For additional guidance, visit our How to Measure a Trailer Axle Guide.

What size brakes are included?

Each axle includes pre-installed 12″ × 2″ electric brake assemblies. Since this is a tandem axle kit, braking components are installed on both axles, providing four brake assemblies for dependable stopping performance and improved towing control.

What are Posi-Lube® spindles?

Rockwell American Posi-Lube® spindles feature an integrated grease fitting and internal lubrication passage that allows fresh grease to be distributed through the hub assembly during routine maintenance. This simplifies bearing lubrication while helping extend bearing life when serviced according to the manufacturer’s recommendations.

Why choose slipper springs instead of double-eye springs?

Slipper spring suspensions are commonly used on heavy-duty tandem axle trailers because they offer a simple, durable design with fewer moving parts. They are well suited for equipment trailers, dump trailers, car haulers, and commercial applications where strength, reliability, and easy maintenance are important.

What trailers are these tandem axle kits commonly used on?

These Rockwell American Tandem 7,000 lb Electric Brake Trailer Axle Kits with Slipper Springs are commonly used on equipment trailers, car haulers, dump trailers, gooseneck trailers, flatbed trailers, enclosed cargo trailers, utility trailers, farm trailers, and custom heavy-duty trailer builds.

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Resources & Downloads

• Rockwell American Trailer Axle Service Manual
• How to Measure a Trailer Axle
• Shop Trailer Axles
• Documents & Downloads
• Johnson Trailer Parts YouTube Channel

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Installation Video

Watch our installation video for helpful guidance on trailer axle measurements, tandem suspension setup, hanger placement, axle replacement, and general trailer axle installation.

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Questions?

Need help selecting the correct tandem axle kit, verifying your Hub Face (HF) and Spring Center (SC) measurements, or choosing the right suspension configuration? Our knowledgeable team is happy to help verify your trailer measurements and ensure you receive the correct components before you order.

Call or Text: (602) 292-9690

Email: sales@johnsontrailerparts.com

Whether you’re replacing worn trailer axles, upgrading your suspension, or building a new trailer from the ground up, we’re here to help you complete your project with confidence.