Best 3 Leaf Springs for Trailer: 5 Options Compared

If your trailer sags, bounces, or just doesn’t ride like it used to, worn leaf springs are likely the culprit. Upgrading to a quality 3-leaf set can restore stability, improve load support, and give you peace of mind on the road.

This guide compares five top options, including direct-fit replacements and heavy-duty pairs. You’ll see how each spring’s length, arch, and capacity match different trailer types, so you can pick the best 3 leaf springs for your trailer without guesswork.

Dorman 929-1029 – Reliable 1500 lb Replacement

The Dorman 929-1029 is a direct replacement leaf spring designed to match the fit and function of your trailer’s original springs. With a 26-inch length, 4 1/4-inch arch, and 3-leaf construction, it supports up to 1500 pounds. It’s an ideal solution if your current springs are damaged from overloading, collision, or corrosion, or if they’re simply due for replacement.

Dorman builds these springs from quality materials to strict specifications, ensuring reliable performance and a long service life. As a premier aftermarket leaf spring provider in the USA, they back their engineering with solid support. If you need a straightforward, trustworthy swap for a 1500 lb capacity trailer, this spring delivers exactly what you expect.

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• Direct replacement – these leaf springs are designed to match the fit and function of the original leaf springs on specific vehicles or trailers
• Ideal solution – seamlessly replaces leaf springs damaged by overloading, collision, cracking or corrosion, or are due for replacement
• Durable construction – made from quality materials to strict specifications to ensure reliable performance and long service life
• Trustworthy quality – engineered, manufactured and supported by the premier aftermarket leaf spring provider in the USA
• Support available – every Dorman part is backed by Dorman's ASE Blue Seal Certified technical support team

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Trailer Supplies Pair – 1500 lb Capacity Set

This pair of 24.25-inch 3-leaf radius end springs from Trailer Supplies gives you a complete axle upgrade. Each spring supports 750 pounds, for a combined 1500 lb capacity on a single axle. The 1-3/4-inch width fits most 1.5K trailer axles, and the radius end design simplifies installation on many common hangers.

Durable black bushings with a 9/16-inch inner diameter are included to absorb road shock and provide a smoother ride. The set directly replaces popular OEM models like Dexter 4331-07B, UNA-178, and UNA-203. If you want a ready-to-install pair that matches standard trailer specs, this is a convenient and cost-effective choice.

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• Heavy-Duty Load Capacity – Each 3-leaf spring supports up to 750 lbs; combined 1,500 lbs capacity for a single axle trailer.
• Standard Size Fit – Measures 24-1/4" from eye center to hook end, with 1-3/4" wide spring profile to fit most 1.5K trailer axles.
• Durable Construction – Includes high-strength black bushings (9/16" inner diameter); built to absorb road shock and provide a smoother ride.
• OEM Replacement Codes – Direct replacement for Dexter 4331-07B, UNA-178, UNA-203 and compatible with TS820-3, WE-3, WIE-3, LR24503F, and other popular models.
• Universal Application – Ideal for single axle utility trailers, boat trailers, cargo haulers, and other light-duty applications.

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Aeagle 4-Leaf Kit – 1750 lb per Spring

The Aeagle 25-1/4-inch double eye spring kit offers a higher capacity with 4 leaves per spring, supporting 1750 pounds each for a total of 3500 pounds on your trailer axle. It includes two springs and a U-bolt kit with four 5-1/2-inch U-bolts and lock nuts. The 1-3/4-inch width and 3-inch free open fit many 3500 lb axles, but note it only fits round axles, not square.

Each spring features an anti-rust coating for good corrosion resistance, and Aeagle uses high-quality raw materials for strength. This kit replaces part number SW4B and comes with bushings installed. If you need extra load capacity and a complete hardware set, this is a robust option for heavier trailers.

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• Replaces for Part Number: SW4B,not fit square axle,Only fit round axle.
• Includes: 2 x 4-Leaves Double Eyes Springs; 3500lbs axle U-bolt kit(Kit includes: 4 x 5-1/2" long U bolts, U-bolt thread diameter is 1/2",the thread length of the U-bolt bolt is 2 inches.the curvature (inside diameter) of the U-bolt is 2 4/9"; 2 x tie plates for 1-3/4" leaf springs; 8 x 1/2"-20 hex nuts). And this kit used for 2-3/8" dia round trailer axles.
• Parameters: 1750 lb capacity per spring for 3,500 lbs trailers; eye to eye length: 25-1/4", free open: 3", width of leaf: 1-3/4", 4 leaves, 9/16" bushing dia, 2 bushings installed for each spring, leaf thickness: 5/16".（Note: The nut should be tightened horizontally. Failure to do so will affect the final user experience）
• Durability: Each of AEAGLE trailer leaf spring kit with anti-rust coating for good corrosion resistance. We always choose raw material with high quality to make our products strong, durable and ensure reliable performance and long use time.
• Quality Assurance: 12-month warranty! Tested before shipping.

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Dorman 929-1019 – 2000 lb Eye/Eye Spring

The Dorman 929-1019 is another direct replacement leaf spring, but with a higher 2000-pound capacity. It measures 25 1/4 inches eye-to-eye with a 3-inch arch and 3-leaf construction. Like its sibling, it’s built to match the fit and function of original springs on specific vehicles or trailers, making it a seamless swap for damaged or worn parts.

Dorman’s durable construction uses quality materials to strict specifications, ensuring reliable performance and long service life. As a premier aftermarket leaf spring provider in the USA, they engineer and support their products thoroughly. If your trailer needs a 2000 lb capacity and you want a trusted brand, this spring is a solid choice.

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• Direct replacement – these leaf springs are designed to match the fit and function of the original leaf springs on specific vehicles or trailers
• Ideal solution – seamlessly replaces leaf springs damaged by overloading, collision, cracking or corrosion, or are due for replacement
• Durable construction – made from quality materials to strict specifications to ensure reliable performance and long service life
• Trustworthy quality – engineered, manufactured and supported by the premier aftermarket leaf spring provider in the USA
• Support available – every Dorman part is backed by Dorman's ASE Blue Seal Certified technical support team

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Johntruck Shackle Bolts – Installation Hardware

The Johntruck 4-pack of 9/16-18 x 3-inch leaf spring shackle bolts with lock nuts is essential hardware for installing 1-3/4-inch wide leaf springs. These bolts fit double eye leaf springs and are common on trailers with 2,000 lb and 3,500 lb axles. They secure your springs to hanger brackets or equalizers, ensuring a safe and stable setup.

Made from heat-treated Grade 5 steel, these bolts are sturdy, high strength, and durable. The threads are deep and clear for even force and good tightening strength. You get four bolts and four lock nuts for easy installation. If you’re replacing springs or building a trailer, this hardware kit is a practical addition.

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• 【Fitment】Fits for installing 1-3/4” wide leaf spring and double eye leaf springs onto hanger bracket or equalizers. It is common on trailers that have a 2,000lb and 3,500lb axles.
• 【Function】These 9/16"-18 x 3" trailer leaf spring shackle bolts with lock nuts are used to fix your leaf springs to the leaf spring hangers and also to the center equalizer bar of the trailer.
• 【High Quality】Grade 5. Made of heat-treated steel, sturdy, high strength and durable. Threads per inch: 18. The threads are deep and clear, with even force and good tightening strength when used. Good rust and corrosion resistant.
• 【What You Will Get】Comes with 4 bolts and 4 lock nuts. Easy installation.
• 【100% Satisfaction Guarantee】The johntruck Team aims to provide you the best products and services. We support 30 days returns and 12 months warranty. Please feel free to contact us if you have any question.

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Buyer’s Guide: What to Consider

Choosing the right 3 leaf springs for your trailer involves a few key factors. Here’s what to consider before you buy.

• Load Capacity: Match the spring's capacity to your trailer's gross axle weight rating (GAWR). Overloading can cause sagging or failure.
• Spring Length & Arch: Measure eye-to-eye length and arch height to ensure proper ride height and alignment with your trailer's hangers.
• Leaf Count: More leaves generally mean higher capacity but a stiffer ride. 3-leaf springs balance load support and comfort.
• End Type: Eye/eye, eye/hook, or radius ends must match your hanger brackets. Double eye springs are common for many trailers.
• Hardware Included: Some kits come with U-bolts, bushings, or shackle bolts. Check what you need for a complete installation.

Conclusion

Finding the best 3 leaf springs for your trailer comes down to matching capacity, length, and end type to your axle. The Dorman springs offer reliable direct replacements, while the Trailer Supplies pair gives you a complete set. For heavier loads, the Aeagle 4-leaf kit provides extra strength.

Don’t forget the Johntruck shackle bolts if you need installation hardware. Review your trailer’s specs and pick the spring that fits your needs. A proper upgrade will restore your trailer’s ride and safety.