Single Trailer Leaf Spring 4 Leaf Double Eye 1750 lb Cap - Hanger

In this review of the Single Trailer Leaf Spring kit, the bottom line is straightforward: this set is aimed at trailer owners who need a direct, heavy-duty replacement spring assembly for a 3,500 lb axle. It blends a compact 25-1/4' eye-to-eye leaf spring with a complete hanger and U-bolt kit, and the single biggest reason to buy is the matched fitment and materials choice that give dependable load support and straightforward installation for trailers built around SW4B round axles.

Key Features

• 4-leaf construction: Provides layered strength and controlled flex so the trailer maintains stability under typical 1,750 lb per-spring loads.
• 25-1/4' eye-to-eye length: A common OEM-compatible length that makes this a practical swap for trailers specified for SW4B springs.
• Complete hanger kit included: Comes with tall and short hangers plus shackle straps and bolts so mounting hardware matches the springs and reduces sourcing extra parts.
• 3,500 lb axle U-bolt kit: Includes four 5-1/2' U-bolts, tie plates and nuts sized for 2-3/8' round axles which simplifies axle-to-spring clamping during install.
• 60Si2Mn manganese steel: Heat-treatable material with a two-coat painted surface for increased strength and corrosion resistance in trailer use.

Who It's For

This kit is best for owners of small utility, landscape, or light equipment trailers using a 3,500 lb axle and SW4B-compatible springs who want a matched replacement set. The included hangers, shackle straps and axle U-bolts make it a convenient single-purchase option for a two-spring replacement job.

It is not appropriate for cars, trucks, vans, tractors, or any vehicle other than trailers; do not buy this product if you need automotive suspension parts for motorized vehicles. Also, if you need leaf springs with different eye-to-eye length or higher per-spring capacity, look for a different assembly.

Pros & Cons

Pros

• Durable material and paint finish deliver solid corrosion resistance and long service life for trailer use.
• Matched hardware bundle saves time sourcing hangers, shackle straps and U-bolts separately.
• Straightforward fit for SW4B and standard 2-3/8' round axles, making installation faster for experienced DIYers.

Cons

• Designed only for trailers and will not fit or function on automobiles or other motor vehicles.
• Some buyers may debate value for money despite good functionality and fit; cost expectations vary.

Specifications

Leaves	4
Eye-to-eye length	25-1/4' (25.25 in)
Free open	3' (3 in)
Leaf width	1-3/4' (1.75 in)
Bushing diameter	9/16' (0.5625 in)
Leaf thickness	5/16' (0.3125 in)
Spring capacity	1,750 lb per spring (kit fits 3,500 lb axle)

Our Verdict

The Single Trailer Leaf Spring kit is a practical, no-surprises replacement for trailers built around SW4B springs and 3,500 lb axles. With heat-treatable manganese steel leaves, a full hanger and U-bolt kit, and common OEM dimensions, it is a sensible value for trailer owners who prioritize fit and straightforward installation over specialized or vehicle-grade suspension parts.

Frequently Asked Questions

Will these springs fit my 3,500 lb axle?
Yes, the kit is specified for a 3,500 lb axle using 2-3/8' round trailer axles and supplies the matching U-bolt hardware.

Are these springs suitable for cars or trucks?
No. These leaf springs are designed only for trailers and are not compatible with cars, trucks, vans, or tractors.

What hardware is included?
The kit includes U-bolts, tie plates, hex nuts, hangers, shackle straps, shackle bolts and locknuts so you get a complete mounting set for installation.