ICON V.S. 2.5 Piggyback CDC Rear Shocks for 2007-2018 GM 1500, Pair

The ICON Vehicle Dynamics V.S. 2.5 Aluminum Series Piggyback Reservoir Shocks with CDC Valve are a vehicle-specific rear shock pair engineered for 2007–2018 GM 1500 trucks running 0–1.5 inches of rear lift. Each shock is tuned in both length and damping specifically for this application, combining a nitrogen-charged monotube body with a piggyback reservoir and ICON's externally adjustable CDC Valve for on-the-fly compression control.

Shipping: ICON parts ship direct from ICON Vehicle Dynamics, mostly by UPS Ground. Lead times vary by part and some items are built to order, so please allow extra time. We email tracking as soon as your order ships.

Bump Zone Technology Prevents Harsh Bottom-Outs

A 6061 billet aluminum manifold positioned below the top cap creates an internal Bump Zone that increases damping force by 20% as the shock approaches full compression. For a GM 1500 used off-road at speed, that progressive resistance means the suspension slows down before it runs out of travel rather than slamming to a stop, reducing chassis stress and keeping the truck composed over repeated hits.

Ten Levels of Compression Adjustment

The CDC (Compression Damping Control) Valve is an externally adjustable knob that restricts oil flow into the piggyback reservoir, producing 10 distinct compression damping ranges. Dialing up adds resistance for loaded hauling or high-speed trail running; dialing down softens the ride for daily driving. No tools are required, and the shock does not need to be removed to make the adjustment. The piggyback reservoir also improves heat dissipation during prolonged off-road use, reducing shock fade when the suspension is working hardest.

Built to Be Rebuilt

The V.S. 2.5 shocks use a one-piece digressive piston, a 7/8-inch induction-hardened chrome-plated shaft, PTFE-lined spherical bearings, and one-piece impact-extruded aluminum cylinders. Premium 5WT shock oil maintains consistent damping across a wide temperature range. Every unit is 100% rebuildable and 100% revalveable, so the shock can be serviced and retuned rather than replaced when wear or a change in use case demands it.

Features

• CDC Valve: 10-level external compression damping adjustment with a single knob
• Internal Bump Zone: 6061 billet aluminum manifold adds 20% damping force near full compression
• Piggyback Reservoir: nitrogen-charged monotube with separate reservoir for improved heat dissipation
• 7/8" Hardened Shaft: induction-hardened, chrome-plated for durability and corrosion resistance
• PTFE Spherical Bearings: application-specific mounting hardware included
• Rebuildable and Revalveable: fully serviceable; 5WT shock oil for wide-temperature consistency

Specifications

Who This Is For and Isn't

These shocks suit 2007–2018 GM 1500 owners running 0–1.5 inches of rear lift who want adjustable, rebuildable performance shocks for mixed on-road and off-road use, including loaded hauling, high-speed trail driving, and daily driving where ride quality matters.

These shocks are not compatible with GM 1500 models equipped with Magnetic Ride Control, are not recommended for Hybrid model variants, and are not a fit for trucks with more than 1.5 inches of rear lift. Installation may require slight modifications to the rear shock absorber mounts. California residents: this product contains chemicals known to the State of California to cause cancer, birth anomalies, or other reproductive harm (Prop 65).

Common Questions

What GM 1500 model years do these shocks fit?

The ICON V.S. 2.5 Piggyback CDC rear shocks (SKU 77700CP) are fitment-specific to 2007–2018 GM 1500 trucks with 0–1.5 inches of rear lift. They are not compatible with Magnetic Ride Control-equipped models and are not recommended for Hybrid variants of that generation.

How does the CDC Valve adjustment work?

The CDC (Compression Damping Control) Valve is an external knob on the piggyback reservoir that restricts oil flow between the shock body and reservoir. Turning it cycles through 10 distinct compression damping levels, with no tools required, allowing the driver to firm up for off-road or loaded use and soften for daily driving without removing the shock.

What is the Bump Zone and why does it matter?

The Bump Zone is created by a 6061 billet aluminum manifold positioned below the shock's top cap. As the shock nears full compression, this manifold increases damping force by 20%, progressively slowing suspension travel before it bottoms out. For high-speed off-road use, that means less harsh impact on the chassis and better control through repeated compression events.

Are these shocks rebuildable?

Yes. The ICON V.S. 2.5 Aluminum Series shocks are 100% rebuildable and 100% revalveable. The one-piece digressive piston, 5WT shock oil, and CNC-machined aluminum components are all serviceable, meaning the shocks can be rebuilt or retuned to a different valving specification rather than replaced outright.

What mounting hardware is included?

The ICON V.S. 2.5 Piggyback CDC rear shock pair includes PTFE-lined spherical bearings and application-specific mounting hardware for the 2007–2018 GM 1500 fitment. Slight modifications to the rear shock absorber mounts may be required during installation.