This YukonGM 14-Bolt 40 Spline Spool is built from high quality steel to deliver maximum strength and durability in extreme off-road and competition use. This GM 14-Bolt Steel Spool replaces the factory differential, locking both rear wheels together for f
This YukonGM 14-Bolt 40 Spline Spool is built from high quality steel to deliver maximum strength and durability in extreme off-road and competition use. This GM 14-Bolt Steel Spool replaces the factory differential, locking both rear wheels together for full-time traction. Ideal for trail rigs, mud trucks, and rock bouncers running 10.5" 14-Bolt axles.
Includes:
Specifications
| Specification | Detail |
|---|---|
| Brand | Yukon Gear & Axle |
| Material | Steel |
| Axle Type | GM 10.5" 14-Bolt Truck |
| Spline Count | 40 Spline |
| Gear Ratio Compatibility |
4.10-and-down gear ratio |
| Traction Type | Full Spool (Locked 100%) |
| Recommended Use |
Off-Road / Competition Only |
Fitment
| Year | Make | Model |
|---|---|---|
| 1973 2020 | Chevrolet | C20 / C30 / K20 / K30 / Silverado 2500 / Silverado 3500 |
| 1973 2020 | GMC | C25 / C35 / K25 / K35 / Sierra 2500 / Sierra 3500 |
| 1975 1993 | Chevrolet / GMC | Suburban 2500 / 3500 |
| 1975 1993 | Chevrolet / GMC | Van G30 / G35 |
| 1973 1991 | Chevrolet | Blazer / K5 (with 14 Bolt Rear Swap) |
Tech Insight
A spool permanently locks both axle shafts together, sending equal torque to both wheels at all times. Unlike a locker or limited-slip differential, a spool contains no moving parts and provides constant 100% traction.
This Yukon spool is designed for GM 14 Bolt applications using 4.56 and numerically higher gear ratios, including 4.56, 4.88, 5.13, and 5.38 gear sets.
Generally, yes. Because a spool has no internal gears, clutches, or locking mechanisms, it is one of the strongest differential options available. This makes it popular in rock bouncers, drag cars, mud trucks, and dedicated off-road vehicles.
A spool is not recommended for regular street use. Because both wheels are permanently locked together, turning on pavement causes tire scrub, increased driveline stress, and reduced handling characteristics.
A 40 spline setup provides increased axle shaft strength compared to smaller spline counts. Combined with a spool, it creates an extremely durable drivetrain package capable of handling large tires, V8 horsepower, and severe off-road abuse.
