SEHNSUCHT 4-Leaf Trailer Spring Replacement Kit, 2-Pack 3,500 lb Single-Axle — U-Bolts & Hangers, Pre-Fitted Bushings

This SEHNSUCHT replacement kit supplies everything needed to refresh a single-axle trailer suspension: two 4-leaf springs rated 1,750 lb each (for a combined axle rating of 3,500 lb), U-bolts and tie plates sized for a 2-3/8" round axle, plus hangers, shackle straps and fasteners. Each spring is made from heavy-duty carbon steel with an anti-rust coating, pre-fitted with bushings and sized to match common SW4B arrangements. The kit is aimed at homeowners, mechanics and trailer owners who need a direct-fit replacement rather than a custom rebuild.

How do the springs match my trailer's weight and size requirements?

Each spring is rated at 1,750 lb, making the pair suitable for a standard 3,500 lb single axle. Dimensions and bushing sizes are provided to help confirm fit before purchase.

• Spring capacity: 1,750 lb each (total axle support 3,500 lb)
• Eye-to-eye length: 25-1/4"; free arch: 3"
• Leaf width: 1-3/4"; leaf thickness: 5/16"; 4 leaves per spring
• Bushing diameter: 9/16"; two bushings pre-installed per spring

What components arrive in the U-bolt and hanger assemblies?

The kit includes axle mounting hardware and suspension hangers sized to work with the included 1-3/4" leaf springs and 2-3/8" axle. All parts are matched so you receive a complete, installation-ready set.

• U-bolts: 4 × 5-1/2" long, 1/2" thread diameter, 2 4/9" inside curvature
• Tie plates: 2 plates made for 1-3/4" leaf spring width; 8 hex nuts (1/2"-20)
• Hangers: 2 × 3" tall and 2 × 2.1" tall hangers for standard mounting points
• Shackles/hardware: 4 shackle straps (eye-to-eye 3.09"), 6 × 9/16"-18 × 3" shackle bolts with locknuts

How durable and corrosion-resistant are these replacement parts?

Springs are formed from heavy-duty carbon steel and receive an added anti-rust coating for extended service life in outdoor conditions. Fasteners and plates are sized and treated to resist wear and keep clamping force steady when installed correctly.

• Carbon steel construction for strength and fatigue resistance
• Anti-corrosion finish applied to springs for longer life
• Pre-installed bushings reduce initial fitment work and wear
• Note: tighten nuts horizontally to maintain correct clamping and ride quality

Can I install this myself and what should I check during fitment?

The kit is designed for direct replacement of SW4B-style springs and includes the common hardware needed. Basic mechanical skills and standard tools are sufficient, but carefully verify measurements and torque directions to ensure safe installation.

• Confirm axle diameter (2-3/8") and spring width (1-3/4") before installing
• Replace both springs as a pair to maintain balanced suspension behavior
• Tighten nuts horizontally as recommended to avoid misalignment
• If unsure, consult a trailer technician to verify hanger locations and torque specs

Who is this for: This SEHNSUCHT kit is for trailer owners and repair shops seeking a direct SW4B replacement for a 3,500 lb single-axle trailer. It fits common small to medium utility, boat, or equipment trailers that use 1-3/4" leaf packs and 2-3/8" axles, and for anyone wanting a bundled solution with springs, U-bolts and hangers included.