LEAF SPRING US-1091: 1-3/4” wide, 8 Leaf, 14″ (26″) approx: 4,000 lbs.

Description

Generic Trailer Spring: 1-3/4” wide, 8 Leaf spring, 14″ (26″) approx: 4,000 lbs.

Repair or replace your trailer’s suspension with our double-eye leaf spring, also known as an eye-by-eye trailer spring, designed for reliable performance and optimum load carrying capacity on light-duty trailers. This is a common style of leaf spring that features an “eye” at both ends of the spring with nylon or brass bushings. This spring mounts either above or below the trailer axle and secures to standard hangers and shackles for a smooth, controlled ride. 

Built from heat-treated spring steel, each trailer spring is engineered to handle loads while reducing bounce, excessive friction, and sway on the roughest of roads. Whether you’re replacing worn springs, upgrading your suspension, or building a new trailer, these springs offer a perfect combination of strength, stability, and durability. These are available in a variety of leaf counts and weight ratings to match your axle capacity. Our double eye leaf springs are ideal for single, tandem, or triple axle trailer configurations.

Key Features of the US‑1091 8‑Leaf Spring

• Constructed from heat-treated spring steel for strength and durability
• 8-leaf design for dependable load support and stability
• Double-eye configuration for secure suspension attachment
• Pre-installed nylon bushings to help reduce friction and wear
• 9/16″ eye diameter for compatibility with appropriate mounting hardware
• Designed for demanding trailer and hauling applications
• Helps maintain proper ride height under load
• Built to withstand repeated towing and heavy-duty use

Best Applications for a 4,000 lb Trailer Leaf Spring

The US-1091 8-leaf spring is well-suited for a variety of light-duty towing and hauling applications where reliable load support and suspension performance are essential, such as:

• Boat trailers
• Campers
• Small RVs and travel trailers
• Utility trailers
• Snowmobile trailers
• Landscape and equipment trailers
• Cargo trailers
• ATV and UTV trailers
• Small construction trailers
• Recreational towing applications

How to Measure an 8‑Leaf Trailer Spring

Selecting the correct replacement spring starts with accurate measurements. Follow these simple steps:

Step 1: Measure Eye-to-Eye Length:

Measure from the center of one spring eye to the center of the other. This spring measures 26 inches.

Step 2: Measure the Eye Diameter:

Measure the inside diameter of the spring eye where the mounting bolt passes through. This spring features a 9/16-inch eye diameter.

Step 3: Count the Leaves:

Count the individual spring leaves in the pack. This model has 8 leaves, providing support for 4,000 lb trailer leaf springs applications.

8-Leaf Spring vs 7-Leaf vs 5-Leaf: Choosing the Right Capacity

Choose a trailer spring based on your trailer’s weight and application. Having the proper capacity helps maintain ride height, improve stability, reduce wear, and support safer towing performance.

8‑Leaf: 4,000 lbs, provides a softer ride for boat trailers & RVs

Ideal for boat trailers, campers, and utility trailers requiring balanced load support and comfort.

7‑Leaf (US‑1092): 4,550 lbs, offers a stiffer ride for heavy utility trailers

For heavier loads and demanding utility-trailer applications, it offers greater capacity and additional support. Its stiffer suspension characteristics make it well-suited for equipment trailers and commercial hauling.

→ Need a stiffer 4,550 lb spring? See the 7‑Leaf US‑1092 here

5‑Leaf (US‑1075): 3,000 lbs, ideal for light‑duty applications

Designed for lighter-duty trailers where lower load capacity and a more flexible suspension are preferred. It is commonly used on smaller utility, recreational, and cargo trailers.

→ Need a lighter 3,000 lb spring? See the 5‑Leaf US‑1075 here

Installation Tips for Double-Eye Trailer Springs

Proper installation helps maximize suspension performance, safety, and component lifespan. Following recommended hardware, replacement, and torque guidelines can help prevent premature wear and future suspension issues.

Do I Need New U-Bolts When Replacing Leaf Springs?

New U-bolts are strongly recommended whenever leaf springs are replaced. U-bolts stretch under load and may not provide proper clamping force if reused.

Should I Replace Both Left and Right Springs at the Same Time?

It is recommended that both springs be replaced together to maintain balanced ride height and load support. Installing only one new spring may create uneven suspension performance.

Torque Specs for 9/16” Spring Eye Bolts

Always follow the trailer or hardware manufacturer’s specifications for torque values. Proper torque helps secure the spring assembly while preventing excessive wear on bushings and mounting components.

Frequently Asked Questions About 8-Leaf Springs

What is the exact weight capacity of an 8-leaf 26” trailer spring?

The US-1091 8-leaf trailer spring is rated for 4,000 lbs of capacity. It is commonly used on boat trailers, utility trailers, small RVs, and other light-duty towing applications requiring dependable load support.

Can I replace a 5-leaf spring with an 8-leaf spring?

An 8-leaf spring can replace a 5-leaf spring if the dimensions and trailer requirements match. Because an 8-leaf trailer spring provides greater load support, it may affect ride characteristics and suspension performance.

Will a 4,000 lb spring ride softer than a 4,550 lb spring?

A 4,000 lb spring typically provides a softer ride than a 4,550 lb spring. Springs with higher capacities are generally designed to handle heavier loads and may feel stiffer when carrying lighter weights.

What bushings fit a 9/16” eye diameter spring?

Bushings designed for a 9/16-inch spring eye diameter should be used with this leaf spring. Always verify bushing dimensions and hardware compatibility before installation to ensure proper fitment.

How long do light-duty trailer leaf springs last?

Light-duty trailer leaf springs can last many years when properly maintained and used within their rated capacity. Factors such as load weight, road conditions, corrosion, and maintenance practices can affect service life.

Do you ship to Canada?

No, currently John’s Spring only ships within the continental U.S.

What is the return policy if this spring does not fit?

Return eligibility depends on the product’s condition and the purchase terms. Contact us before installation if you have fitment concerns, and we can help determine the best solution.

Can I use this 8-leaf spring on a heavy equipment trailer?

Heavy equipment trailers often require springs with higher weight capacities than this 4,000-lb model offers. For heavier-duty applications, consider the US-1092 7-leaf spring, which offers a 4,550 lb capacity and is better suited for demanding loads.