Finding the right leaf spring setup is crucial for safe and smooth trailer operation. This guide highlights five 3500 lb leaf spring options, each designed to fit SW4B round axles with a 25-1/4″ eye-to-eye length and a 1750 lb per-spring capacity. Explore solid manganese steel construction, corrosion protection, and complete U-bolt or hanger kits to match your trailer’s needs. The table below offers a quick snapshot of the choices to help you compare at a glance.
| Product | Brand | Capacity | Length | Notes |
|---|---|---|---|---|
| Trailer Leaf Spring 4 Leaf Double Eye 1750 lbs Cap for 3500 lbs Axle Suspension 25-1/4″ Length fits for SW4B – Set 2 | Magorfas Store | 1750 lb per spring (3500 lb trailer) | 25-1/4″ | 2nd-grade manganese steel, corrosion-ready coating |
| Youxmoto 3500lb Single Trailer Axle Suspension Kit 1750lb Leaf Springs & Ubolt Kit; Pair of Trailer Leaf Spring 4 Leaf Double Eye, 25-1/4″ L, 1-3/4″ Width | Youxmoto Store | 1750 lb per spring (3500 lb trailer) | 25-1/4″ | Includes U-bolts and hanger components |
| Single Trailer Leaf Spring 4 Leaf Double Eye 1750 lbs Cap for 3500 lbs Axle Suspension, Hanger & U-Bolt kit 25-1/4″ Length fits for SW4B | Magorfas Store | 1750 lb per spring (3500 lb trailer) | 25-1/4″ | Complete hanger and hardware options |
| Single Trailer Leaf Spring 4 Leaf Double Eye 1750 lbs Cap for 3500 lbs Axle Suspension & U-Bolt kit, 25-1/4″ Length fits for SW4B – Set 2 | Magorfas Store | 1750 lb per spring (3500 lb trailer) | 25-1/4″ | Corrosion-protected manganese steel with dual set |
| Trailer Leaf Spring Kit 3500lb Single Trailer Axle 4 Leaf Spring Kit with U-Bolt Kit & Single Trailer Axle Hanger Kit | Autoholic Store | 1750 lb per spring (3500 lb trailer) | 25-1/4″ | Adaptor kit with hangers and U-bolts |
Trailer Leaf Spring 4 Leaf Double Eye 1750 lbs Cap
This kit uses four-leaf springs with a 25-1/4″ eye-to-eye length and a 1-3/4″ leaf width. Each spring provides up to 1750 lb capacity, suitable for a 3500 lb trailer configuration. Constructed from manganese steel (60Si2Mn) for strength and longevity, with dual paint coatings for improved corrosion resistance. The kit is designed for SW4B fitment and includes hardware selections to ensure proper installation. Consider this option when replacing a complete spring pair and upgrading to a robust, corrosion-resistant suspension solution.
Youxmoto 3500lb Leaf Spring & U-Bolt Kit
The Youxmoto 3500 lb kit includes four 5-1/2″ long U-bolts, two tie plates for 1-3/4″ springs, and a complete 2-3/8″ axle design. The four-leaf springs feature a 25-1/4″ eye-to-eye length, 1-3/4″ leaf width, and 5/16″ thickness, rated at 1750 lb per spring for a 3,500 lb trailer. The design highlights a horizontal nut tightening requirement to maintain proper fit and operation. This set aims to deliver enhanced strength, longevity, and ease of assembly for systems using SW4B round axles.
Single Trailer Leaf Spring 4 Leaf Double Eye Set
This set repeats the 4-leaf, 25-1/4″ eye-to-eye dimension with a 1-3/4″ leaf width and 5/16″ leaf thickness. It features 1750 lb per-spring capacity for a 3,500 lb trailer and includes a U-bolt kit for 2-3/8″ round axles. The kit also provides complete hanger components and shackle hardware. Emphasizing horizontal tightening, the package ensures accurate assembly and long-term reliability in SW4B applications, backed by a manganese steel composition and protective coating.
Single Trailer Leaf Spring 4 Leaf Double Eye Set With U-Bolt Kit
This option mirrors the four-leaf design with a 25-1/4″ eye-to-eye length and 1-3/4″ leaf width, offering 1750 lb per spring capacity for a 3500 lb trailer. The package includes corrosion-resistant manganese steel springs with two coats of paint for protection. A U-bolt kit and hanger hardware is included to support a straightforward swap on SW4B round axles. Applicants should verify load rating compatibility with their trailer model before installation.
Trailer Leaf Spring Kit 3500lb Single Trailer Axle
This kit emphasizes an adaptation for standard 3500 lb trailer axles with four-leaf, double-eye springs measuring 25-1/4″ in eye-to-eye length. Each spring supports up to 1750 lb, for a total of up to 3500 lb. It includes a complete set of U-bolts and hanger hardware, along with engineered manganese steel springs to withstand frequent use. The design focuses on effective cushioning and reduced chassis stress, offering a balanced approach to trailer suspension upgrades without overhauling existing axle configurations.
Buying Guide
- Load rating and axle compatibility: Confirm the total trailer weight and axle diameter (commonly 2-3/8″ for these sets) to ensure correct fitment and performance.
- Spring configuration: A 4-leaf, double-eye design provides higher load capacity and durability than simpler configurations, but assess ride harshness and intended use.
- Material and finish: Manganese steel (60Si2Mn) offers strength and resilience; surface coatings improve corrosion resistance for outdoor use.
- Length and geometry: Eye-to-eye length of 25-1/4″ is common for SW4B applications; verify exact measurements for your trailer.
- Hardware included: U-bolts, tie plates, hangers, and shackle bolts should be checked to match your axle and frame setup.
- Installation considerations: Some sets require horizontal nut tightening for proper acceptance; follow manufacturer instructions to avoid improper seating.
- Maintenance and lifespan: Regular inspection for cracks, wear at mounts, and coating integrity extends suspension life.
- Warranty and replacement parts: Look for kits that provide complete hardware and easy access to replacement springs or components.