Aeagle Trailer Leaf Spring Kit 25-1/4" 4-Leaf Double-Eye 1750 lb Springs with U-Bolt Kit

Aeagle's 25-1/4" 4-leaf double-eye trailer spring kit is a direct-fit replacement for SW4B-style round-axle setups, offering 1,750 lb capacity per spring and a complete 3500 lb axle U-bolt kit for 2-3/8" round trailer axles.

This kit combines two pre-assembled 4-leaf double-eye springs with a matched U-bolt, tie plate and nut set so you can replace worn suspension components in one service visit. Each spring is designed for round trailer axles (not square axles) and includes installed bushings, an anti-rust finish, and specification details printed for installers. The kit aims to restore factory ride height and load-handling on trailers rated around 3,500 lb.

How does this spring kit match my trailer's load and axle type?

The springs are rated at 1,750 lb each, so the pair supports a combined 3,500 lb axle capacity when installed as intended. They are tailored for round axles with a 2-3/8" diameter and replace SW4B-style parts; they are not compatible with square axles.

• Rated capacity: 1,750 lb per spring (3,500 lb per axle pair).
• Designed for 2-3/8" round trailer axles, not for square axles.
• Part cross-reference: replaces SW4B-style components.
• Eye-to-eye length: 25-1/4"; free open height: 3".

What components are included and what are their dimensions?

The package contains two 4-leaf double-eye springs plus all hardware needed to secure them to the axle: four U-bolts, two tie plates and matching nuts. The U-bolts and plates are sized to clamp a 1-3/4" leaf spring on a 2-3/8" round axle with standard thread engagement.

• 2 x 4-leaf double-eye springs with 9/16" bushings installed (2 per spring).
• 4 x U-bolts — 5-1/2" long, 1/2" thread diameter, ~2" thread length, inside curvature ≈ 2.4".
• 2 x tie plates for 1-3/4" leaf packs and 8 x 1/2-20 hex nuts.
• Leaf thickness: 5/16"; leaf width: 1-3/4"; 25-1/4" eye-to-eye length.

How durable and easy to install are these replacement springs?

Aeagle applies an anti-rust coating to each spring for corrosion resistance and uses high-quality raw steel to improve longevity under trailer conditions. The springs ship with installed bushings and include all U-bolt hardware so you can replace the leaf packs and clamp them without sourcing extra parts.

• Anti-corrosion coating for outdoor durability and longer service life.
• Pre-installed bushings reduce installation steps and alignment issues.
• Kit includes U-bolts, tie plates and nuts—no additional hardware required.
• Manufacturer recommendation: tighten nuts horizontally to avoid assembly issues.

Who is this kit best for? This Aeagle kit is ideal for trailer owners, DIY mechanics, and repair shops that need a drop-in replacement for worn SW4B-style leaf springs on 2-3/8" round-axle trailers rated near 3,500 lb. Choose this set when you want factory-style dimensions—25-1/4" eye-to-eye length, 1-3/4" leaf width, and 4-leaf pack construction—plus a bundled U-bolt kit to complete the axle reassembly. If your trailer uses a square axle or has different suspension geometry, consult your axle or spring specifications before purchasing.