Radflo 2.5 Front Coilover Kit – Toyota FJ Cruiser / 4Runner – 6" Rough Country Lift | 6CT-001-20

Upgrade the front suspension of your 6-inch lifted Toyota or Lexus with the Radflo 2.5-Inch Front Coilover Kit, part #6CT-001-20, specifically designed for vehicles equipped with a 6-inch Rough Country suspension lift.

This complete front coilover pair combines large 2.5-inch Radflo shock bodies with Eibach coil springs, providing a premium replacement or performance upgrade for the front struts supplied with compatible 6-inch Rough Country suspension systems.

Radflo's 6CT-001-20 coilovers feature an Internal Floating Piston (IFP) design, nitrogen-gas pressurization, velocity-sensitive deflective-disc valving and Radflo's aluminum Freeflo piston for controlled, consistent performance on the street and off-road.

Each Radflo OE replacement shock is built to order and uniquely valved for the vehicle and application, providing a serviceable and tunable alternative to conventional replacement struts.

Sold as a pair – one complete front coilover kit services both sides of the vehicle.

Vehicle Fitment

Designed for applicable vehicles equipped with a:

6-Inch Rough Country Suspension Lift

Toyota FJ Cruiser

• 2007 FJ Cruiser

• 2007 TRD Special Edition

• 2008 FJ Cruiser

• 2008 Trail Teams Special Edition

• 2009 FJ Cruiser

Toyota 4Runner

• 2003-2009 4Runner SR5

• 2003-2009 4Runner Sport

• 2003-2009 4Runner Limited

Lexus GX470

• 2003-2009 GX470

Critical Fitment Note

This is NOT a conventional stock-height or 2-3 inch lift coilover.

Radflo specifically configures 6CT-001-20 for vehicles using a 6-inch Rough Country suspension lift.

A 6-inch Rough Country IFS lift changes the suspension geometry and coilover mounting relationship compared with a conventional suspension lift. The coilover used with this system must therefore be designed around that specific lifted configuration.

Customers with stock suspension or a typical 2-3 inch suspension lift should select the appropriate standard Radflo coilover instead.

Key Features

• Genuine Radflo Suspension Technology

• Part number 6CT-001-20

• Sold as a pair

• Designed for compatible 6-inch Rough Country lift systems

• Front coilover assembly

• 2.5-inch diameter shock bodies

• Eibach coil springs included

• Internal Floating Piston (IFP) design

• Nitrogen-gas pressurized to 250 PSI

• Radflo aluminum Freeflo piston

• Velocity-sensitive deflective-disc valving

• Self-adjusting damping

• SSID alloy-steel shock bodies

• CNC-machined 6061 aluminum body-cap eyelets

• Black-anodized body-cap components

• High-temperature foam-resistant Radflo suspension fluid

• Mirror-polished chrome-plated steel shock rods

• PTFE-coated machined bronze rod guides

• Rebuildable combination quad-ring and lip seals

• Consumer or factory tunable

• Consumer or factory serviceable

• OE-location mounting

• Built to order

• Application-specific valving

• Made in the USA

• 1-Year Limited Warranty

Designed for 6-Inch Rough Country Lift Systems

The 6CT-001-20 is a specialized coilover rather than a conventional lifted FJ Cruiser or 4Runner coilover.

It is designed specifically around the suspension configuration created by a 6-inch Rough Country lift.

This makes the Radflo kit particularly useful for owners who already have a Rough Country 6-inch suspension system but want to replace the original front struts with a higher-performance, rebuildable coilover.

Rather than removing the entire 6-inch lift system, the Radflo coilovers allow customers to retain the lift configuration while upgrading the front dampers.

Excellent Replacement for Worn 6-Inch-Lift Front Struts

Front struts supplied with an older 6-inch suspension lift eventually wear just like any other shock absorber.

The Radflo 6CT-001-20 provides a premium replacement solution for customers who want more than a basic replacement strut.

The Radflo upgrade provides:

• Larger 2.5-inch shock bodies

• Eibach coil springs

• Application-specific valving

• Rebuildable construction

• Tunable valving

• Premium internal components

• Nitrogen-gas pressurization

• Long-term serviceability

This makes the kit particularly attractive for an older FJ Cruiser, 4Runner or GX470 where the original 6-inch lift remains in place but the front dampers need replacement.

Complete Coilovers with Eibach Springs

The 6CT-001-20 includes Eibach coil springs.

This is an important distinction from replacement shock cartridges or bare front dampers.

Radflo combines its 2.5-inch shock assembly with quality Eibach springs to create a complete front coilover solution for the 6-inch Rough Country application.

Sold as a Pair

Unlike the matching Radflo rear shocks, the 6CT-001-20 front coilover kit is sold as a pair.

One kit includes the front coilovers needed for:

Driver Side + Passenger Side

You do not need to order quantity two to complete the front axle.

2.5-Inch Shock Bodies

Each Radflo front coilover uses a large:

2.5-Inch Diameter Shock Body

The larger shock body provides increased suspension-fluid capacity and improved heat management compared with smaller conventional replacement shocks.

This is particularly useful for lifted SUVs used for:

• Daily driving

• Highway driving

• Rough roads

• Washboard roads

• Trail use

• Overlanding

• High-speed off-road driving

• Repeated suspension cycling

Internal Floating Piston Design

The front coilovers use an:

IFP – Internal Floating Piston

The floating piston separates the suspension fluid from the pressurized nitrogen gas.

This design helps minimize aeration and cavitation of the shock fluid during repeated suspension cycling, allowing the damper to maintain more consistent performance as operating conditions become more demanding.

250 PSI Nitrogen Pressurization

Radflo specifies the 6CT-001-20 at:

250 PSI

The nitrogen charge helps maintain positive pressure on the suspension fluid, reducing the potential for cavitation and helping the shock maintain consistent damping during rapid suspension movement.

Velocity-Sensitive Deflective-Disc Valving

Radflo uses:

Velocity-Sensitive Deflective-Disc Valving

The valving responds to the velocity of shock movement, allowing damping characteristics to change based on how quickly the suspension is moving.

This helps provide a balance between:

• Everyday ride quality

• Steering control

• Body control

• Small-bump compliance

• Larger suspension impacts

• Off-road suspension movement

Radflo lists the damping adjustment as self-adjusting.

Radflo Freeflo Piston

Each coilover incorporates Radflo's:

Aluminum Freeflo Piston

The Freeflo piston works with the deflective-disc valving to control the movement of suspension fluid through the shock.

The system is designed to provide predictable damping characteristics across varying road and trail conditions.

High-Temperature Suspension Fluid

Radflo uses its:

High-Temp Foam-Resistant Suspension Fluid

Suspension fluid can become extremely hot during repeated shock cycling. Excessive heat and aeration can reduce damping consistency.

Radflo's high-temperature fluid is designed to resist foaming and maintain more consistent damping as operating temperatures increase.

Premium Internal Construction

Radflo uses high-quality materials throughout the 6CT-001-20.

Shock Body: SSID alloy steel
Body Style: SSID alloy-steel tube
Body Cap/Eyelets: CNC-machined 6061 aluminum
Body Cap Finish: Black anodized
Piston: Radflo aluminum Freeflo piston
Shock Rod: Steel
Rod Finish: Mirror-polished chrome plating
Rod Guide: Machined bronze
Rod Guide Finish: PTFE coating
Seal: Rebuildable combination quad-ring and lip seal
Spring: Eibach
Suspension Fluid: Radflo high-temperature foam-resistant oil

Rebuildable & Serviceable

One of the major advantages of upgrading to Radflo is long-term serviceability.

Radflo lists the 6CT-001-20 as consumer or factory serviceable.

Rather than treating the entire coilover as a disposable component when the seals and fluid eventually wear, the shock can be serviced and rebuilt.

This can be particularly valuable for an FJ Cruiser, 4Runner or GX470 that will remain in service for many years.

Tunable Valving

Radflo also specifies the 6CT-001-20 as:

Consumer or Factory Tunable

This provides the ability to tailor damping characteristics for specialized vehicle configurations.

Custom tuning may be beneficial for vehicles carrying substantial additional front-end weight from equipment such as:

• Steel front bumpers

• Winches

• Skid plates

• Brush guards

• Auxiliary lighting

• Dual-battery systems

• Other permanent accessories

Built to Order

Radflo states that its OE replacement shocks are:

Custom Built to Order

The shocks are uniquely valved to meet the requirements of the vehicle and application.

Radflo currently lists an average build turnaround of approximately 10 days.

Build time can vary, so customers with a vehicle apart or an upcoming installation should allow sufficient time when ordering.

OE-Location Mounting

Radflo lists the mounting configuration as:

OE Location and Hardware

The 6CT-001-20 is designed to integrate with the suspension arrangement used by the compatible 6-inch Rough Country lift rather than requiring a custom fabricated coilover mount.

Matching Rear Shock Option

For customers replacing the complete suspension on a compatible 6-inch Rough Country lifted FJ Cruiser, 4Runner or GX470, Radflo also offers a matching 2.5-inch rear shock application.

Matching Rear Radflo Shock: 6ST-001-20

The rear 6ST-001-20 uses a 2.5-inch shock body with a remote reservoir and is also specifically configured for the 6-inch Rough Country lift.

NOTE: The rear shocks are sold individually, so quantity 2 is required for a complete rear set.

Pairing the 6CT-001-20 front coilovers with the 6ST-001-20 rear shocks provides a premium Radflo suspension solution for an existing 6-inch Rough Country lift system.

What's Included

The Radflo 6CT-001-20 Front Coilover Kit includes:

• (2) Radflo 2.5-inch front coilover shock assemblies

• (2) Eibach coil springs

• Application-specific mounting configuration

Sold as one complete front pair.

Product Specifications

Manufacturer: Radflo Suspension Technology
Part Number: 6CT-001-20
Series: 600R Pro
Product Type: Front Coilover Kit
Position: Front
Sold As: Pair
Lift Application: 6-Inch Rough Country Lift
Lift Height: 6.0 Inch
Shock Diameter: 2.5 Inch
Shock Type: IFP
Shock Style: Coilover
Springs: Eibach
Top Mount: Top Hat
Bottom Mount: Eye
Reservoir Type: Internal Floating Piston
Pressurization: Nitrogen Gas
Nitrogen Pressure: 250 PSI
Adjustment: Self-Adjusting
Valving: Velocity-Sensitive Deflective Disc
Piston: Radflo Aluminum Freeflo Piston
Body Material: SSID Alloy Steel
Body Style: SSID Alloy-Steel Tube
Body Cap Material: CNC-Machined 6061 Aluminum
Body Cap Finish: Anodized
Rod: Steel
Rod Finish: Mirror-Polished Chrome Plating
Rod Guide: Machined Bronze
Rod Guide Finish: PTFE Coating
Seal: Rebuildable Combination Quad Ring & Lip Seal
Shock Oil: Radflo High-Temp Foam-Resistant Suspension Fluid
Mounting: OE Location & Hardware
Tuning: Consumer or Factory Tunable
Service: Consumer or Factory Serviceable
Vehicle Type: Truck/SUV
Country of Origin: USA
Warranty: 1-Year Limited Warranty

Frequently Asked Questions

What is Radflo part #6CT-001-20?
The 6CT-001-20 is a pair of 2.5-inch Radflo front coilovers with Eibach springs, specifically configured for compatible Toyota and Lexus vehicles equipped with a 6-inch Rough Country suspension lift.

Are the Radflo 6CT-001-20 coilovers sold individually or as a pair?
They are sold as a pair. One kit provides both front coilovers.

Do the coilovers include springs?
Yes. Radflo specifies Eibach coil springs with the 6CT-001-20.

Will these fit a 2007-2009 Toyota FJ Cruiser?
Yes. Radflo specifically lists the 2007, 2008 and 2009 Toyota FJ Cruiser, including the 2007 TRD Special Edition and 2008 Trail Teams Special Edition.

Will these fit a 2010-2014 FJ Cruiser?
Radflo's current fitment data for 6CT-001-20 stops at the 2009 FJ Cruiser. Do not assume compatibility with 2010-2014 models without confirming the suspension application with Radflo.

Will these fit a Toyota 4Runner?
Yes. Radflo's current application data includes 2003-2009 Toyota 4Runner SR5, Sport and Limited models equipped with the applicable 6-inch Rough Country suspension lift.

Will these fit a Lexus GX470?
Yes. Radflo currently lists 2003-2009 Lexus GX470 applications.

Will these work on a stock-height FJ Cruiser?
No. This particular version is specifically configured for the 6-inch Rough Country lift.

Can I use these with a normal 2-3 inch suspension lift?
No. Customers with a conventional 2-3 inch suspension lift should use the appropriate Radflo standard-lift coilover application instead.

Are these remote-reservoir coilovers?
No. Radflo specifies the 6CT-001-20 as an Internal Floating Piston (IFP) coilover. Do not confuse these with Radflo remote-reservoir front coilover models.

Are the coilovers adjustable?
Radflo lists the damping adjustment as self-adjusting. These do not use an external compression-adjuster knob.

Can the Radflo coilovers be rebuilt?
Yes. Radflo lists the 6CT-001-20 as consumer or factory serviceable.

Can the valving be changed?
Yes. Radflo specifies the coilovers as consumer or factory tunable.

What rear shocks match these front coilovers?
For the corresponding 6-inch Rough Country lift application, use Radflo 6ST-001-20 2.5-inch rear remote-reservoir shocks. Rear shocks are sold individually, so order quantity 2.

Are these a good replacement for worn Rough Country front struts?
The 6CT-001-20 is specifically designed around the 6-inch Rough Country lift application, making it a premium rebuildable and tunable replacement option when the original front dampers need replacement.

Where are Radflo shocks made?
Radflo lists the country of origin as USA.

What warranty does Radflo provide?
Radflo lists a 1-Year Limited Warranty for the 6CT-001-20.