ICON Stage 2 S2 Secondary Shock Upgrade System for 2007-2021 Toyota Tundra

The ICON Vehicle Dynamics Stage 2 S2 Secondary Shock Upgrade System is a front suspension upgrade for 2007–2021 Toyota Tundra trucks that adds a 2.5 Series CDC Valve secondary shock alongside an existing ICON coilover, effectively doubling the front suspension's damping capacity for more demanding off-road terrain.

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Double the Damping, Same Track Width

Adding a secondary shock to an existing ICON coilover setup means the front suspension can absorb rougher terrain and larger obstacles without the compromise of a single-shock arrangement. The S2 system uses the factory lower control arms and maintains OE track width, so wheel fitment and handling geometry stay consistent with the original build. For Tundra owners who have already invested in an ICON coilover and want meaningfully more capability without replacing what they have, the S2 upgrade extends that investment rather than starting over.

Ten-Position Compression Adjustment On-Trail

ICON's Compression Damping Control Valve (CDC Valve) technology gives the driver 10 distinct compression curve settings, adjustable without tools on the trail. Softer settings absorb washboard and high-frequency chop; firmer settings control body motion on fast, open terrain. That range of adjustment means one setup can serve daily driving and weekend off-road use without a shop visit between the two.

Modular, Rebuildable Construction

The S2 system fits within a staged upgrade path. Tundra owners can add it to an existing ICON coilover system rather than committing to a full long-travel kit. The 2.5 Series secondary shocks are fully rebuildable and revalveable, so the investment holds its value over the life of the vehicle. Mounting hardware includes billet aluminum shock tower adapters, fabricated shock hoops, and steel lower shock mounts.

Features

• 2.5 Series CDC Valve secondary shocks: vehicle-specific tuning with increased damping and oil volume
• 10-position compression adjustment: quick on-trail damping changes via CDC Valve technology
• Factory lower control arm compatibility: no replacement control arms required; OE track width maintained
• Billet aluminum shock tower adapters: included with fabricated shock hoops and steel lower shock mounts
• Fully rebuildable and revalveable shocks: serviceable for long-term use
• Modular design: integrates with existing ICON coilover setups as a staged upgrade

Specifications

California Residents: This product contains chemicals known to the State of California to cause cancer, birth anomalies, or other reproductive harm.

Who This Is For and Isn't

The S2 Secondary Shock Upgrade System suits 2007–2021 Toyota Tundra owners who already have an ICON coilover installed on the front suspension and want to add a secondary shock for greater damping capacity on rough off-road terrain. It is compatible with OEM wheels and tires and with the recommended ICON Alloys fitments listed above.

This system is not a standalone lift kit and cannot be used without an existing ICON coilover setup already installed. It is not compatible with other aftermarket suspension kits (Application Note #17). Installation requires welding (Application Note #59); this is not a tool-free or drill-only install. Tires larger than 35x12.50 in may require fender trimming and additional modifications.

Common Questions

Does this system work without an existing ICON coilover installed?

No. The ICON Stage 2 S2 Secondary Shock Upgrade System is designed to add a secondary shock alongside an existing ICON coilover on 2007–2021 Toyota Tundra trucks. It is not a standalone suspension kit and will not function as a complete front suspension solution on its own.

Does installation require welding?

Yes. Application Note #59 states that welding is required as part of the S2 system installation on the 2007–2021 Toyota Tundra. This is not a fully bolt-on install, and professional installation by a qualified fabricator or suspension shop is advisable.

Can this system be used with other aftermarket suspension kits?

No. Application Note #17 states that the Stage 2 S2 Secondary Shock Upgrade System is a stand-alone kit and must not be used in conjunction with any other aftermarket suspension kits. It is designed specifically to pair with an existing ICON coilover setup.

What does the CDC Valve adjustment do?

The CDC Valve (Compression Damping Control Valve) on the 2.5 Series secondary shocks provides 10 distinct compression curve settings. Adjusting the valve changes how the shock responds to compression inputs, allowing the driver to tune the front suspension for different terrain types or driving conditions without removing the shock from the vehicle.

What is included in the kit?

The ICON Stage 2 S2 Secondary Shock Upgrade System includes one S2 Hoop Kit (part 56109) and one pair of S2 2.5 Series CDC Valve secondary shocks (part 57722CP), along with billet aluminum shock tower adapters, fabricated shock hoops, and steel lower shock mounts. The system ships in multiple boxes.