Spicer Dana 60 Front Axle Upper Kingpin Bushing Preload Tension Spring (1975-1999 Ford, GM & Dodge)

Eliminate violent front-end shimmy, cure loose steering play, and restore critical knuckle alignment with this genuine Spicer Upper Kingpin Bushing Preload Tension Spring. Specifically engineered as a direct original equipment manufacturer (OEM) replacement component, this high-tensile coil spring (Part Number: 37300) is designed to fit classic open-knuckle solid Dana 60 front steering axles found on vintage Ford, GM, and Dodge heavy-duty 4x4 trucks.

On a classic kingpin solid front axle, handling stability depends entirely on continuous vertical preload applied to the upper steering knuckle components. Positioned inside the top steering knuckle cap, this heavy-duty spring pushes directly down against a steel retainer plate, which in turn tightly seats and centers the tapered nylon kingpin bushing. Over years of hard off-road trail wheeling, commercial hauling, or heavy snowplowing with oversized mud-terrain tires, this spring naturally suffers metal fatigue. As it heat-cycles and compresses millions of times, it sags, loses its spring rate, or cracks. When this tension drops, slack is instantly introduced into the steering knuckle assembly. This loss of preload results in rapid, uneven front tire wear, persistent lane drift, and aggressive front-end steering oscillations commonly referred to as the "death wobble."

Sourcing a genuine Spicer 37300 spring guarantees your front end is restored using the exact spring rate and wire diameter specified by the factory blueprints. Fabricated from premium, case-hardened spring steel, this heavy-coil replacement resists permanent sagging or premature collapse under extreme impact loads and rough terrain. Whether you are performing a preventative front axle overhaul or fixing a dangerous steering wobble on a classic work truck, installing a fresh OEM tension spring ensures your knuckle geometry remains tight and responsive.

Component Highlights:

• Restores Critical Preload: Delivers the exact downward vertical force required to anchor the internal nylon steering bushing firmly against the upper kingpin, keeping steering play at zero.

• Cures Leaf-Spring Death Wobble: Eradicates the destructive front-end steering wheel oscillations and vibrations caused by worn-out, sagged, or broken internal knuckle springs.

• Genuine Spicer OEM Quality: Precision-coiled by the vehicle’s original factory drivetrain supplier to guarantee exact metallurgical limits and an extended operational lifespan.

• Heavy-Duty Spring Steel: Engineered to withstand extreme cyclic compression without taking a permanent set or losing its tension profile under high torque loads.

Vehicle & Axle Fitment:

• Axle Profile: Open-Knuckle, Solid Front Dana 60 Axles running classic upper spring-loaded kingpin configurations. Does not fit later ball-joint style front axles, newer generation Super Duty trucks, or modern AAM axle housings.

• Ford Trucks: 1978 to 1998 Ford F-250 and F-350 4x4 heavy-duty truck platforms utilizing kingpin Dana 60 front axle housings.

• GM / Chevrolet Trucks: 1979 to 1991 K30, K3500, and V3500 1-ton 4x4 heavy-duty trucks.

• Dodge Trucks: 1975 to 1993 Dodge W200, W250, W300, W350, D600, and D700 4x4 models running Dana 60 front axles.

• Position: Front Axle Steering Knuckle Assemblies — Inside Top Kingpin Cover Cap (Left or Right Side). Note: Springs are sold individually. Two springs are required to fully service both sides of the front axle housing.