This 37-spline steel spool for Dana 80 axles is a cost-effective solution for achieving 100% traction in off-road and racing applications. Designed to replace the factory differential carrier, it permanently locks both axle shafts together, ensuring equal torque delivery to both wheels at all times.

Manufactured from high-quality 8620 steel and heat treated for added strength, this spool is built to handle extreme loads and harsh conditions. Ideal for rock crawlers, mud trucks, and drag racing vehicles, it provides a simple, durable, and reliable drivetrain upgrade.

Includes:

• (1) Yukon Dana 80 37-Spline Steel Spool for 4.10 & Up Gear Ratios

Specifications

• Manufacturer: Yukon
• P/N: YP FSD80-4-37
• Fits: Dana 80 rear axles
• 37-spline axle compatibility
• Designed for 4.10 and up gear ratios
• Provides 100% traction to both wheels
• 8620 heat-treated steel construction
• Installs in place of factory differential carrier
• Designed for off-road and racing use
• Not recommended for street-driven vehicles

Fitment

• Dana 80 Rear Axle (Chrysler Dana Spicer)
• 37-spline applications
• 4.10 and numerically higher gear ratios only

Tech Insight

What is a spool and how does it work in a Dana 80 axle?

A spool replaces the factory differential carrier and permanently locks both axle shafts together. Unlike an open differential or locker, a spool has no moving internal parts and delivers 100% of available torque to both wheels at all times. This provides maximum traction and strength for off-road and racing applications.

What are the advantages of a Dana 80 spool over a locker?

A spool is typically stronger, simpler, and more affordable than a locking differential. Because it contains no gears, clutches, or locking mechanisms, there are fewer potential failure points. For dedicated race vehicles, mud trucks, and rock crawlers, a spool often provides the ultimate combination of reliability and traction.

Is a Dana 80 spool suitable for street driving?

No. A spool permanently locks both axle shafts together, forcing both tires to rotate at the same speed. On pavement, this causes tire scrub, increased drivetrain stress, and poor turning characteristics. Spools are best reserved for dedicated off-road, competition, or race vehicles where maximum traction is the primary goal.

What gear ratios does this Dana 80 spool fit?

This Yukon Dana 80 spool is designed for 4.10 and numerically higher gear ratios. Always verify your axle configuration, carrier requirements, and gear ratio before ordering to ensure compatibility with your Dana 80 differential.

Why is a Dana 80 axle popular in extreme off-road builds?

The Dana 80 is one of the strongest production truck axles ever built, featuring a massive ring gear, large axle shafts, and exceptional load-carrying capacity. Combined with a steel spool, a Dana 80 becomes a highly durable drivetrain solution for rock bouncers, mud trucks, diesel performance trucks, drag vehicles, and extreme off-road applications.