Rockwell American 3,500 lb Idler Trailer Axle Kits

Rockwell American 3,500 lb Idler Trailer Axle Kits

Whether you’re replacing a worn axle or building a trailer from the ground up, these Rockwell American 3,500 lb idler trailer axle kits provide a reliable starting point for utility trailers, cargo trailers, landscape trailers, boat trailers, and other light-duty single-axle applications.

Rockwell American trailer axles are part of the Dexter family of trailer axle brands and are trusted by trailer builders, repair shops, and haulers across the U.S. for dependable towing performance and durable construction.

Choose from axle-only, suspension, build, and running gear configurations to match your trailer project, whether you need a simple replacement or a complete setup.

Available in multiple hub face and spring center sizes, these kits range from axle-only replacements to complete running gear systems with wheels and ST205/75R15 radial trailer tires.

All configurations feature Rockwell American axle components with Posi-Lube® greaseable spindles, cambered axle tubes, and durable powder-coated construction designed for long-term trailer performance and easier maintenance.

Free shipping in the lower 48 states.

Compare Kit Options

Select the trailer axle package that best matches your trailer build or repair requirements.

← Swipe left/right to compare all kit options →

Axle Only: Includes a Rockwell American 3,500 lb idler axle with pre-installed idler hubs and Posi-Lube® spindles. Ideal for replacing an existing axle while reusing your current suspension components.

Suspension Kit: Includes the axle, double-eye leaf springs, and U-bolt kit for replacing the primary suspension components on a single-axle trailer.

Build Kit: Complete single-axle suspension package including the axle, leaf springs, U-bolt kit, and single-axle hanger kit for new trailer builds or full suspension replacements.

Running Gear Kit: Complete running gear package including the axle, leaf springs, U-bolt kit, hanger kit, wheels, and ST205/75R15 radial trailer tires for a near bolt-on trailer setup.

Build Kit and Running Gear Kit configurations are commonly selected for complete trailer builds, while Axle Only and Suspension Kit options are popular for repairs and partial upgrades.

Choose Your Axle Size (Hub Face / Spring Center)

Select the hub face (HF) and spring center (SC) measurements that match your trailer frame and suspension setup for proper alignment, tire clearance, and safe towing performance.

• Hub Face (HF): Measured from the outer face of one hub to the outer face of the opposite hub
• Spring Center (SC): Measured from the center of one spring seat to the center of the opposite spring seat

Matching the correct hub face and spring center measurements helps ensure proper fender clearance, spring alignment, wheel positioning, and overall trailer fitment.

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

Key Features

• Rockwell American Quality: Genuine Rockwell American axles are made in the USA and supported by the Dexter family of trailer axle brands.
• 3,500 lb Capacity: Designed for utility trailers, cargo trailers, landscape trailers, boat trailers, and other light-duty towing applications.
• Idler Axle Configuration: Pre-welded 4-bolt brake flanges allow compatible electric trailer brakes to be added later if desired.
• Posi-Lube® Spindles: Built-in grease zerks allow quick bearing lubrication without removing the hubs.
• Durable Powder-Coated Finish: Helps resist corrosion from road debris, weather, and moisture exposure.
• Cambered Axle Beam: Designed to improve tire wear, towing stability, and tracking performance under load.

Fitment Notes

These Rockwell American 3,500 lb idler trailer axle kits fit many common single-axle trailer applications including utility trailers, cargo trailers, landscape trailers, boat trailers, and equipment trailers.

Always verify your trailer’s overall GVWR, wheel ratings, tire ratings, and suspension capacity before loading.

Be sure to verify your hub face measurement, spring center measurement, bolt pattern, wheel and tire specifications, and included components before ordering since exact specifications vary by selected configuration.

Frequently Asked Questions

Helpful Resources

• Rockwell American Axle Service Guide
• Trailer Hanger Kit Spacing Guide
• How to Measure a Trailer Axle
• Johnson Trailer Parts YouTube Channel

Installation Video

Watch our video for trailer axle tips, measurements, installation guidance, and trailer suspension setup information.

Questions?

Need help choosing the right axle size or trailer axle kit configuration? We can help confirm your measurements and fitment before you order.

Call (602) 292-9690,
email sales@johnsontrailerparts.com,
or contact us through our website.