FOX 2.5 Performance Smooth Body HTO 4-6″ Rear Lift IFP Shocks for 2011-2019 GMC Sierra 2500HD

Description
FOX 2.5 Performance Smooth Body HTO 4-6″ Rear Lift IFP Shocks for 2011-2019 GMC Sierra 2500HD

FOX 2.5 Performance Smooth Body HTO 4-6 inches Rear Lift IFP Shocks for 2011-2019 GMC Sierra 2500HD

Part Number: 2×987-24-035_n3

Summary: The FOX 2.5 Performance Series HTO is a bolt-on shock absorber designed to enhance both on and off-road performance for lifted heavy-duty trucks. Featuring an Internal Floating Piston (IFP) and position-sensitive technology, this shock addresses the need for improved damping capacity on vehicles with 4-6 inches of rear lift. The larger 2.5-inch diameter body and aluminum construction work together to manage heat and provide consistent control under demanding conditions.

Features

• Internal Floating Piston (IFP): The internal floating piston (IFP) separates the shock oil from the high-pressure nitrogen to provide optimized damping and prevent oil aeration.
• Hydraulic Top Out (HTO): A secondary HTO shim stack slows down shock shaft speed to reduce harsh top-outs and increase comfort during rebound.
• 6061-T6 Aluminum Body: 2.5” Impact extruded aluminum with Type II clear-anodized plating provides efficient heat dissipation and corrosion resistance to ensure long-term durability.
• High-Flow Damping: Velocity-sensitive damping technology provides vehicle-specific valving to ensure improved ride quality on and off the pavement.

Technical Specifications

Fitment

• 2011-2019 GMC Sierra 2500HD
• Note: Configured for vehicles with 4-6 inches of rear lift.

What’s Included

• Includes 2 Shocks

Why Choose This Product?

• Engineering Advantage: The 2.5-inch smooth body design utilizes Hydraulic Top Out (HTO) technology to manage the increased forces associated with heavier wheel and tire packages and higher lift heights.
• Performance Benefit: Drivers experience reduced harshness during suspension extension and more consistent damping response thanks to the heat-dissipating aluminum body and IFP architecture.

Frequently Asked Questions

What does the Hydraulic Top Out (HTO) technology do?
HTO reduces harsh top-outs by forcing shock oil through a secondary shim stack, which slows the shock shaft speed as it reaches full extension.

How does the Internal Floating Piston (IFP) improve performance?
The IFP separates the high-pressure nitrogen gas from the shock oil, which prevents aeration and allows the shock to maintain consistent damping performance.

Is this shock compatible with my lift kit?
This specific part is engineered for 2011-2019 GMC Sierra 2500HD models equipped with 4 to 6 inches of rear lift.