4-inch Black Rubber Spool Roller with 5/8" Bore – Fits Boat Trailers (Replaces Yates 23739)

4-inch Black Rubber Spool Roller with 5/8" Bore – Fits Boat Trailers (Replaces Yates 23739)

This 4-inch black rubber spool roller features a 5/8-inch inner diameter bore and is designed for a wide variety of boat trailers. The spool design helps guide the boat's keel, providing smoother loading and unloading operations.

This part is a direct replacement for: Yates 23739, Valmar 80782, and Craton SK344.

• Material: Heavy-duty black rubber for durability.
• Design: Spool shape for self-centering boat alignment.
• Installation: Mounts on a standard 5/8" diameter roller shaft.

Technical Specifications

Recommended Assembly Components

Package Contents

Please Note: This listing is for the roller only. Mounting hardware is sold separately.

• 1 x 4-inch Black Rubber Spool Roller (23739)

Installation Guide

This spool roller is typically mounted on a 5/8" diameter roller shaft (a 5-1/4" long shaft is common for a 4" roller), which fits into a 4" galvanized roller bracket. The roller and shaft are secured together using 5/8" pal nuts hammered onto each end of the shaft. The entire roller bracket assembly then attaches to the trailer's crossmember using U-bolts or other appropriate mounting hardware. The heavy-duty rubber construction and spool design allow for easy loading and unloading of various boat hull types.

Troubleshooting & FAQ

How do I know if this roller will fit my trailer?

This roller is designed for a 4" wide mounting bracket and a 5/8" diameter roller shaft. Measure your existing bracket and shaft to ensure compatibility. It works with most boat trailer frames when used with the correct hardware.

What else do I need to install this roller?

You will need a 5/8" diameter roller shaft (typically 5-1/4" long for a 4" roller), a 4" roller bracket, and 5/8" pal nuts to secure the roller onto the shaft. These are usually sold separately.

What is the difference between a spool roller and a straight roller?

The spool (or "self-centering") design helps guide the boat's keel during loading and unloading, making it easier to center the boat on the trailer. Straight rollers provide a flat support surface without the guiding edges.

OEM vs. Aftermarket?

This listing is an aftermarket replacement part (not an OEM component). We build to OEM specifications using comparable-grade materials. Production is done in an ISO9002-certified facility, and each batch is inspected for consistent performance.

How fast do you ship and how much does it cost?

We offer fast global shipping—typically 5–15 days worldwide—and standard shipping is free. Expedited options are available at checkout depending on your location.

What is your warranty and return policy?

This product includes a 1-year warranty against manufacturing defects under normal use. If something goes wrong, contact our support team with your order details. Returns are accepted within our standard return window (unused & in original condition); please see our policy page or reach out for instructions.

Important Notes

• Verify that the product images and specifications match your original part. If discrepancies exist—even if your model is listed—do not proceed with the purchase.
• This product is an aftermarket replacement part and is not an OEM component.
• Professional installation is recommended to ensure safety and optimal performance.

Why Choose JLM MARINE?

• Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
• Fast Global Shipping: Free delivery worldwide in 5–15 days.
• Direct from Manufacturer: Competitive pricing without compromising quality.