Aeagle 4-Leaf Double-Eye Trailer Spring Kit for 3,500 lb Axle — 25-1/4" Length, 1,750 lb Each, Includes U-Bolts & Hangers

The AEagle 4-leaf double-eye spring kit is a complete suspension replacement designed for 3,500 lb trailer axles, offering 1,750 lb capacity per spring with U-bolts, hangers and shackles included.

This all-in-one trailer suspension kit from AEagle replaces SW4B-style round-axle springs and gives you the parts to rebuild a single 3,500 lb axle assembly. It combines two 4-leaf, double-eye springs with a full U-bolt kit, hangers, shackle straps and fasteners — everything needed to restore ride height, support and axle alignment on trailers that use 1-3/4" wide leaf springs and 2-3/8" round axles.

What does the kit include and how does it fit my trailer?

The kit is built for round trailer axles rated to 3,500 lb and includes two matching springs plus mounting hardware so you can service one axle. It replaces part number SW4B but is not compatible with square axles.

• 2 x 4-leaf double-eye springs (1,750 lb capacity each)
• 4 x 5-1/2" long U-bolts, 1/2" diameter
• 2 x tie plates for 1-3/4" leaf springs, 8 x 1/2"-20 hex nuts
• Hanger kit: 2 x 3" tall hangers, 2 x 2.1" tall hangers
• 4 x shackle straps (eye-to-eye 3.09"), 6 x 9/16"-18 shackle bolts with locknuts

What are the key dimensions and load ratings?

Knowing the measurements helps ensure correct fit and safe loading. Each spring measures 25-1/4" eye-to-eye, 1-3/4" wide, with a 3" free-open height and four leaves composed of 5/16" thick steel per leaf.

• Capacity: 1,750 lb per spring (3,500 lb axle total)
• Eye-to-eye length: 25-1/4"; free-open: 3"
• Width: 1-3/4"; leaf thickness: 5/16"; bushing dia: 9/16"
• 2 bushings installed per spring for secure mounting

How durable is the AEagle spring and what maintenance tips matter?

AEagle uses high-quality raw steel and an anti-rust coating to extend service life and resist corrosion in wet or salty environments. Basic upkeep and correct installation will maximize performance and safety.

• Corrosion-resistant coating for longer life in outdoor use
• Inspect bushings and bolts periodically for wear or looseness
• Important: tighten nuts horizontally to ensure proper fit and ride
• 12-month warranty and pre-shipment testing provided

Can I install this kit myself and what should I watch for during installation?

Experienced DIYers with proper tools can install the kit, but safe installation requires lifting equipment and attention to torque and alignment. If unsure, use a qualified trailer mechanic to avoid safety risks.

• Requires jack stands or a lift for axle support during install
• Follow torque specs for U-bolts and shackle bolts; tighten nuts horizontally
• Confirm axle is round 2-3/8" diameter before purchasing
• Not compatible with square axles — check axle type first

Who this is for: The AEagle 4-leaf double-eye spring kit is aimed at trailer owners, hobbyists and small fleet operators who need a reliable, OEM-style replacement for a 3,500 lb axle using 1-3/4" leaf springs. It’s ideal when you want a complete hardware set to rebuild one axle — including springs, U-bolts, hangers and shackles — and prefer corrosion-resistant components with a one-year warranty. If you have a square axle or need springs for a different capacity, choose a kit matched to those specific requirements.