Best 4 Leaf Springs For Trailer: Compare Sizes and Kits

#1 · Best Overall

1. Youxmoto 3500lb Single Axle Kit

• Weight: 28.7 lb

Best for: Single-Axle Hardware Bundle.

Why it ranks #1: It pairs two 25-1/4-inch, 1,750-pound springs with U-bolts, tie plates, and nuts for a stated 3,500-pound, 2-3/8-inch round axle.

A pair of 1,750-pound springs arrives with U-bolts, tie plates, and nuts in this Youxmoto single-axle kit. Its stated application is a 3,500-pound trailer with a 2-3/8-inch round axle, giving buyers a defined spring-and-hardware package.

The two four-leaf, double-eye springs are rated at 1,750 pounds each for a 3,500-pound trailer, while the included four 5-1/2-inch U-bolts, two tie plates, and eight nuts support a bundled replacement workflow. The kit is specified for a 2-3/8-inch round axle and lists SW4B fitment. Youxmoto cautions that nuts must be tightened horizontally, so installation technique is part of getting the assembly into service as intended.

Skip it if you need four springs for tandem suspension; Youxmoto’s LFLS0005-LYF2 package lists two pairs and a U-bolt and hanger kit.

For a single 3,500-pound round-axle trailer, this kit combines the spring pair with listed mounting hardware. Confirm the 2-3/8-inch axle configuration and follow the horizontal-tightening instruction; the stated kit is not for square axles.

Listed on Amazon as: 3500lb Single Trailer Axle Suspension Kit 1750lb Leaf Springs & Ubolt Kit; Pair of Trailer Leaf Spring 4 Leaf Double Eye, 25-1/4" L, 1-3/4" Width, 9/16 Eye I.D

#2 · Best Hardware Kit

2. Aeagle SW4B Spring Kit

• Package Dimensions: 29.3 x 13 x 4.7 in
• Weight: 29.2 lb

Best for: Spring And U-Bolt Kit Buyers.

Why it ranks #2: This SW4B replacement pair provides 1,750-pound springs and a U-bolt kit specified for 2-3/8-inch round axles.

This Aeagle set combines two 1,750-pound double-eye springs with a U-bolt kit for a 2-3/8-inch round axle. That bundled hardware can streamline a 3,500-pound axle replacement, while the listing identifies the SW4B reference and excludes square axles.

Each spring’s 1,750-pound rating corresponds to the stated 3,500-pound axle application, and the 25-1/4-inch length and 1-3/4-inch width help identify the spring dimensions. The kit includes four 5-1/2-inch U-bolts, tie plates, and eight nuts, so buyers sourcing a spring-and-mounting-hardware package can handle more of the replacement in one order. Its fit is limited to 2-3/8-inch round axles, not square axles, a key installation boundary.

Skip it if you have a square axle; SEHNSUCHT’s LS0002 pair lists springs without specifying a round-axle U-bolt kit.

This Aeagle kit fits buyers replacing springs and mounting hardware on a 3,500-pound trailer axle with a 2-3/8-inch round beam. The round-axle restriction is decisive, so do not choose it for square-axle installations.

Listed on Amazon as: Aeagle 25-1/4" 4-Leaf 1750lb Capacity Double Eye Spring for 3500lb Trailer Axle & U-Bolt Kit, 1.75" Width, 3" Free Open, Replaces for SW4B, 2PCS

#3 · Best Spec Detail

3. SEHNSUCHT SW4B Suspension Kit

• Package Dimensions: 28.49 x 12.14 x 4.96 in
• Weight: 28.8 lb

Best for: SW4B Spring Pair Replacements.

Why it ranks #3: Its pair is specified at 25-1/4 inches, 1,750 pounds per spring, 1-3/4-inch width, and 9/16-inch bushing ID.

Pre-installed bushings are a practical detail on this SEHNSUCHT pair, which lists two 1,750-pound springs for a 3,500-pound axle. Its 25-1/4-inch eye-to-eye length and SW4B replacement reference help buyers focus on a defined suspension application.

The listed 9/16-inch bushing ID and two bushings installed per spring specify the connection detail before installation, while the 25-1/4-inch eye-to-eye length, 1-3/4-inch width, and 3-inch free arch further describe the fit. Each four-leaf spring is rated for 1,750 pounds, supporting the stated 3,500-pound axle class as a pair. SEHNSUCHT also calls out horizontal nut tightening during installation, making that instruction relevant to the replacement workflow.

Skip it if you want U-bolts and tie plates included; Aeagle’s AELS0003Q2 kit lists both for a 2-3/8-inch round axle.

For a 3,500-pound trailer axle using SW4B-style springs, this pair offers specified dimensions and bushings already installed. Follow the horizontal nut-tightening guidance, and treat mounting hardware as a separate requirement because kit contents are not specified.

Listed on Amazon as: 2 Pieces of Replacement for SW4B 4 Leaf Trailer Leaf Spring, 3500lb Single Trailer Axle Suspension Kit, 25-1/4" Length with 1750lb Capacity Double Eyes Leaf Springs and U-Bolt

#4 · Best Spring Pair

4. SEHNSUCHT Double-Eye Springs

• Package Dimensions: 28.3 x 12 x 4.8 in
• Weight: 24.2 lb

Best for: SW4B Spring-Only Pair.

Why it ranks #4: The two SW4B replacement springs state 25-1/4-inch eye-to-eye length, 1,750-pound capacity each, and preinstalled bushings.

Each SEHNSUCHT spring is rated for 1,750 pounds and lists a 25-1/4-inch eye-to-eye length, targeting standard 3,500-pound trailer axles. The pair has pre-installed bushings and a stated SW4B replacement reference, keeping its application and dimensions clear.

The four-leaf springs specify 1-3/4-inch width, 3-inch free opening, 9/16-inch bushing diameter, and 5/16-inch leaf thickness, which helps buyers compare key dimensions with the original suspension. Two bushings are installed on each spring, and the 1,750-pound rating per spring aligns with the stated 3,500-pound axle class. The package is a pair of springs rather than a listed hardware kit, so buyers replacing mounting components will need to source those separately.

Skip it if you need mounting hardware bundled with the springs; Aeagle’s AELS0003Q2 set includes U-bolts, tie plates, and nuts.

This pair suits owners replacing SW4B-style springs on a standard 3,500-pound trailer axle who want the dimensions and bushings specified. Its spring-only listing means you should plan separately for U-bolts and tie plates if needed.

Listed on Amazon as: SEHNSUCHT Trailer Leaf Spring, 4 Leaf 1750lb Capacity Double Eye Leaf Springs for 3500lb Trailer Axle, 25-1/4"L, 1.75" Width, 3” Free Open of Leaf Spring, Replace for SW4B, 2 Pieces

#5

5. Magorfas 3500lb Springs

• Package Dimensions: 28.3 x 12 x 4.7 in
• Weight: 24.3 lb

Best for: 3500-Pound Axle Replacement.

Why it ranks #5: This double-eye pair is listed at 25-1/4 inches and 1,750 pounds per spring for trailers with a 3,500-pound axle.

A 1,750-pound rating per spring gives this Magorfas pair a clear role on trailers with a 3,500-pound axle. Its four-leaf, double-eye layout and 25-1/4-inch length make it a targeted replacement option for SW4B applications, with the set supplying two matching springs.

The listed 25-1/4-inch length and SW4B fit reference help narrow the replacement search to a specific spring setup, while the double-eye ends identify the mounting style. Each spring is rated for 1,750 pounds, corresponding to a 3,500-pound trailer axle when used as a pair. The four-leaf construction is specified, but the listing does not include installation hardware, so buyers replacing a complete suspension assembly should account for that separately.

Skip it if you need axle-mounting hardware in the same package; Aeagle’s 25-1/4-inch spring set includes a U-bolt kit.

For owners replacing a pair of SW4B-style springs on a 3,500-pound trailer axle, this Magorfas set keeps the spring rating and length explicit. Check that the double-eye layout matches your suspension and source mounting hardware separately.

Listed on Amazon as: Trailer Leaf Spring 4 Leaf Double Eye 1750 lbs Cap for 3500 lbs Axle Suspension 25-1/4" Length fits for SW4B – Set 2

#6 · Best Tandem Set

6. Youxmoto Tandem Spring Kit

• Weight: 73.8 lb

Best for: Tandem-Axle Spring Kit.

Why it ranks #6: The listing supplies four springs for a tandem trailer axle, each rated at 1,750 pounds, plus U-bolt and hanger hardware.

Four springs and a U-bolt and hanger kit make this Youxmoto package a broad replacement option for tandem trailer suspension. Each spring is rated at 1,750 pounds, and the listed 25-1/4-inch length and SW4B reference identify its spring format.

The package contains two pairs of four-leaf, double-eye springs, with each spring rated for 1,750 pounds, plus U-bolt and hanger hardware. That makes it relevant to tandem-axle replacement work where multiple springs and related components are needed together. The springs list a 25-1/4-inch eye-to-eye length, 1-3/4-inch width, 9/16-inch bushing diameter, and 3-inch free opening. The U-bolt kit is specified for 2-3/8-inch round axles, and the listing instructs horizontal nut tightening.

Skip it if you need only a pair for one 3,500-pound axle; Youxmoto’s LFLS0003-LYF lists a single-axle spring-and-U-bolt kit.

This package suits owners handling a tandem trailer spring replacement who need four springs and associated hardware together. Check that the listed 2-3/8-inch round-axle U-bolt fit and spring dimensions match the suspension before beginning installation.

Listed on Amazon as: 4 Leaf Springs 1750 lb for 3500lb Tandem Trailer Axle Suspension; U-Bolt & Hanger Kit; 2 Pairs of Trailer Leaf Spring Double Eye, 25-1/4" L, 1-3/4" Width, 9/16 Eye I.D (2 Bushings)

#7

7. Magorfas 5000lb Springs

• Package Dimensions: 28 x 8.5 x 5 in
• Weight: 29.1 lb

Best for: Higher-Capacity Trailer Axles.

Why it ranks #7: Each spring is rated at 2,500 pounds for a stated 5,000-pound trailer application, with 25-1/4-inch double-eye construction.

A 2,500-pound rating per spring puts this Magorfas four-leaf pair in the 5,000-pound trailer-axle category. The 25-1/4-inch double-eye format and SW4 reference give buyers a specific replacement target rather than a general-purpose spring choice.

The stated 2,500-pound capacity per spring aligns the pair with trailers rated for a 5,000-pound axle, making the load class easy to distinguish from lighter options. Its 25-1/4-inch length and SW4 fit reference help identify a potential replacement match, while the double-eye ends and four-leaf build describe the suspension format. The supplied listing does not specify included U-bolts or tie plates, so this is a spring-focused purchase rather than a complete axle kit.

Skip it if you need a complete 3,500-pound axle kit with U-bolts; Youxmoto’s LFLS0003-LYF includes mounting hardware.

Choose this pair when replacing springs for a 5,000-pound trailer axle and the SW4 reference and 25-1/4-inch length suit your setup. Its higher spring rating is the key boundary; verify your application’s required capacity and mounting arrangement.

Listed on Amazon as: Trailer Leaf Spring 4 Leaf Double Eye 2500 lbs Cap for 5000 lbs Axle Suspension 25-1/4" Length fits for SW4 – Set 2

#8

8. Dorman 929-1031 Spring

• Weight: 13.47 lb

Best for: 26-Inch Direct-Replacement Spring.

Why it ranks #8: Its 26-inch, 4-leaf eye-to-eye design is rated for 2,000 pounds, offering a different length and capacity from the common SW4B options.

Dorman specifies a 26-inch eye-to-eye spring with a 4-1/4-inch arch and 2,000-pound capacity, giving replacement shoppers concrete dimensions to compare. Its eye-to-eye design targets utility trailer or vehicle applications where the original spring’s fit and function need to be restored.

The 26-inch length, 1-3/4-inch width, and 4-1/4-inch arch provide useful reference points when matching a worn spring, while the 2,000-pound capacity identifies its load class. Dorman describes it as a direct replacement for specific vehicles or trailers and lists damage from overloading, collision, cracking, or corrosion as replacement scenarios. It is sold as an individual spring, so replacing a pair requires planning for the matching side as well.

Skip it if you need a 25-1/4-inch SW4B spring pair; SEHNSUCHT’s LS0002 lists two springs at that length.

This Dorman spring suits buyers matching a 26-inch, 4-1/4-inch-arch eye-to-eye replacement for a specific trailer or vehicle. Its single-spring listing and application-specific fit make careful dimension matching important before replacing one or both sides.

Listed on Amazon as: Dorman 929-1031 Utility Trailer Leaf Spring, Eye/Eye, 1 3/4" Width, 26" Length, 4 1/4" Arch, 4 Leaf, 2000lb Capacity

#9

9. FWN 791-1060 Spring

• Package Dimensions: 27.8 x 2 x 2 in
• Weight: 13.67 lb

Best for: 26-Inch Four-Leaf Spring.

Why it ranks #9: This 4-leaf spring lists a 26-inch length, 1-3/4-inch width, 4-1/4-inch arch, and 2,000-pound maximum load capacity.

A 4-1/4-inch arch and 26-inch length distinguish this FWN four-leaf spring, which carries a stated maximum load capacity of 2,000 pounds. Those concrete measurements help buyers seeking a dimension-specific replacement rather than a 25-1/4-inch spring.

FWN lists a 1-3/4-inch width, 26-inch length, and 4-1/4-inch arch, allowing a direct comparison with the spring being replaced. The four-leaf design and 2,000-pound maximum capacity identify its construction and load class, while the single-spring listing matters when planning a full pair replacement. The supplied details do not specify an axle application or mounting hardware, so buyers should use the listed dimensions and capacity to assess whether it suits their setup.

Skip it if you need a pair of 25-1/4-inch springs for a 3,500-pound axle; SEHNSUCHT’s LS0002 lists that pair and application.

For a buyer matching a 26-inch, 4-1/4-inch-arch, 2,000-pound four-leaf spring, FWN provides the key dimensions and capacity. The listing is for one spring and gives no axle application, so assess both requirements before choosing it.

Listed on Amazon as: Trailer Leaf Spring, 4 Leaf 2000lb, 26"L, 1.75" W, 4.25" Arch FWN 791-1060

#10

10. Sturdy Built Slipper Springs

• Package Dimensions: 26 x 11.4 x 2.6 in
• Weight: 3.69 lb

Best for: Slipper-Style Hanger Setups.

Why it ranks #10: These 24-1/2-inch slipper-style springs are rated at 1,000 pounds each and require hanger spacing of 24 inches center to center.

Slipper ends distinguish this Sturdy Built pair from double-eye springs, making it a focused option for trailer suspensions using that mounting style. The set contains two four-leaf springs rated at 1,000 pounds each, with stated compatibility for hangers spaced 24 inches center to center.

The slipper-style ends are the central fit consideration: they suit a different hanger arrangement than double-eye springs, so the mounting design should match the trailer before purchase. Sturdy Built lists a 24-inch center-to-center hanger spacing and a 24-1/2-inch spring length, helping buyers compare the assembly against their existing setup. Two springs are supplied, each rated at 1,000 pounds, for 2,000 pounds total capacity across the pair; the listing does not identify included mounting hardware.

Skip it if you need a 3,500-pound axle’s 1,750-pound-per-spring rating; Magorfas’s MFLS0002Q2 pair is listed for that class.

For a trailer with slipper-style hangers spaced 24 inches center to center, this pair offers a clearly stated 2,000-pound total capacity. Match both the hanger geometry and load requirement; it is not a double-eye replacement.

Listed on Amazon as: Trailer Leaf Springs 24 1/2 inch Slipper Style 4 Leaf 2000lb Capacity – Set of 2 24027-2