Axiom Supply Stage 3 FOX 2.5" Performance Leveling System GM HD Truck 2500 / 3500 Silverado / Sierra 2011-2019

Fitment

The Axiom Supply Stage 3 FOX 2.5 Performance Leveling System is a complete suspension upgrade engineered specifically for GM HD trucks requiring increased ride height, corrected suspension geometry, enhanced wheel travel, and premium on-road and off-road ride quality.

Applications include:

2011-2019 Chevrolet Silverado 2500HD

2011-2019 GMC Sierra 2500HD

2011-2019 Chevrolet Silverado 3500HD

2011-2019 GMC Sierra 3500HD

Fitment Notes

Provides up to 2" of front ride height adjustment.

Designed for stock, leveled, and lifted applications.

Includes vehicle-specific FOX 2.5 Performance Series HTO shocks properly sized and valved for leveled GM HD trucks.

Compatible with most aftermarket suspension systems utilizing factory-style upper control arm mounting locations.

Oversized tires exceeding 11.50" in width may contact the control arm when used with certain factory wheel configurations.

Additional wheel offset or wheel spacers may be required depending on tire size and wheel combination.

Features

FOX 2.5 Performance Series HTO Shocks – Includes a complete set of FOX 2.5 Performance Series Hydraulic Top Out (HTO) shocks featuring position-sensitive damping technology, application-specific valving, and large 2.5-inch shock bodies engineered to significantly improve ride quality, suspension control, and performance both on and off-road.

Hydraulic Top Out Technology – FOX HTO technology provides position-sensitive rebound control that reduces harsh top-out events by slowing shock shaft velocity near full extension. This improves ride comfort, suspension stability, and overall vehicle control, especially on leveled trucks running larger and heavier wheel and tire combinations.

Large-Bore 2.5-Inch Shock Bodies – Increased piston area and fluid capacity provide greater damping control and improved resistance to shock fade during towing, off-road use, and extended operation.

Internal Floating Piston Design – FOX IFP technology separates shock oil from high-pressure nitrogen to maintain consistent damping performance and responsiveness under demanding conditions.

Type II Hard-Anodized Aluminum Bodies – Lightweight aluminum construction efficiently dissipates heat while providing outstanding corrosion resistance and long-term durability.

True Double-Shear Construction – Built from identical upper and lower 3/16" steel plates that are precision laser cut and hand welded into a single rigid structure. This true double-shear architecture distributes suspension loads evenly while maximizing strength, rigidity, and long-term durability.

Equipped with AX6292 Grade 12.9 Ball Joints – Every kit includes a pair of Axiom Supply AX6292 bolt-on upper ball joints featuring our Grade 12.9 Extreme-Duty Ball Stud technology for exceptional strength, steering precision, and resistance to deformation under heavy loads.

Forged Torsion Leveling Keys – Designed to provide additional front ride height while maintaining proper torsion bar indexing and adjustment range.

Corrected Suspension Geometry – Restores proper suspension operating angles while improving droop travel and overall suspension performance.

Dual-Position Ball Joint Mounting – Allows the ball joint to be mounted above or below the control arm mounting plate, providing additional flexibility when dialing in alignment settings and suspension geometry.

Precision Laser-Cut Components – Manufactured using computer-designed, laser-cut steel components for exceptional fitment consistency and manufacturing accuracy.

Service-Friendly Design – Improved grease fitting access simplifies routine maintenance and lubrication regardless of control arm orientation.

Premium Bushing System – High-quality bushings and sleeves provide smooth articulation while minimizing unwanted suspension deflection.

Built for Heavy-Duty Use – Engineered to withstand the demands of towing, oversized tires, lifted suspension systems, off-road use, and daily driving.

Lifetime Warranty Protection – Backed by the Axiom No-Nonsense Lifetime Warranty for the original purchaser.

Description

The Axiom Supply Stage 3 FOX 2.5 Performance Leveling System was developed for GM HD truck owners seeking the ultimate combination of ride quality, suspension performance, and long-term durability. By combining premium suspension correction components with a complete FOX 2.5 Performance Series HTO shock package, this system delivers improved stance, enhanced control, and confidence both on and off the pavement.

At the foundation of the system are Axiom Supply forged torsion leveling keys, providing up to 2" of front ride height adjustment to eliminate factory rake and create clearance for larger tire and wheel combinations. Unlike traditional leveling kits that simply raise the front of the truck, the Stage 3 System addresses the suspension changes created by leveling while dramatically improving shock performance.

The included FOX 2.5 Performance Series HTO shocks are specifically selected and valved for leveled GM HD applications. Featuring large 2.5-inch shock bodies, increased fluid capacity, and vehicle-specific damping characteristics, these shocks provide superior control and heat management compared to factory shock absorbers. FOX's Internal Floating Piston (IFP) design separates shock oil from high-pressure nitrogen, ensuring consistent damping performance and reducing fade under demanding conditions.

FOX Hydraulic Top Out (HTO) technology further enhances performance by providing position-sensitive rebound control near full shock extension. By slowing shaft speed as the suspension reaches the end of its travel, HTO technology reduces harsh top-out events while improving comfort, stability, and overall suspension composure. This is particularly beneficial for leveled trucks running larger tires, towing heavy loads, or operating in rough off-road environments where suspension control is critical.

To ensure suspension geometry remains optimized after leveling, the system includes Axiom Supply Heavy-Duty Upper Control Arms featuring a true double-shear construction utilizing identical upper and lower 3/16" steel plates hand welded into a rigid boxed structure. This design distributes suspension loads evenly through the ball joint mounting area while minimizing flex and maintaining alignment integrity under demanding conditions.

Each control arm is equipped with Axiom Supply AX6292 Bolt-On Upper Ball Joints featuring our Grade 12.9 Extreme-Duty Ball Stud technology. Combined with the arm's dual-position ball joint mounting system, installers gain additional alignment flexibility while benefiting from one of the strongest bolt-on upper ball joints available for the GM HD platform.

The result is a complete suspension package engineered to improve appearance, ride quality, wheel travel, suspension performance, and long-term durability without compromise.

Whether your truck spends its time towing, hauling, exploring off-road terrain, or serving as a daily driver, the Axiom Supply Stage 3 FOX 2.5 Performance Leveling System delivers premium ride quality, superior suspension control, and the confidence to tackle any challenge.

Maintenance

Apply 3 pumps of grease to each ball joint during installation.

For continued performance, service each ball joint every 5,000–7,000 miles. Use only the amount of grease necessary to lubricate the joint and avoid over-greasing.

Includes

(2) Axiom Supply Heavy-Duty Upper Control Arms

(2) Axiom Supply AX6292 Grade 12.9 Bolt-On Upper Ball Joints

(2) Axiom Supply Forged Torsion Leveling Keys

(2) FOX 2.5 Performance Series HTO Front Shocks

(2) FOX 2.5 Performance Series HTO Rear Shocks

(4) Control Arm Sleeves

(8) Control Arm Bushings

(1) Complete Installation Hardware Kit

The Axiom No-Nonsense Lifetime Warranty

Our suspension and steering components are warrantied for life to the original purchaser against manufacturer defects, premature wear, or breakage.

Push it to the limit—we don't care.

If the part lets you down, we'll make it right.