Tein Flex Z Coilovers – 1998-2005 Lexus GS300 / 1998-2000 GS400 / 2001-2005 GS430

Transform the ride height, handling, and stance of your JZS160/UZS160-platform Lexus GS with Tein Flex Z Coilovers — a complete, application-specific coilover system engineered for the 1998–2005 GS300, 1998–2000 GS400, and 2001–2005 GS430 with 16-way damping adjustability, ride height adjustment, and Tein’s proven monotube shock construction. The Flex Z delivers a meaningful improvement in handling precision and body control over the factory suspension while offering the ride height flexibility to achieve the stance your build demands — all from one of Japan’s most respected suspension manufacturers.

Key Features:

• 16-way damping adjustability — 16 clicks of rebound damping adjustment for precise tuning between comfort and performance
• Ride height adjustable — threaded lower mounts allow independent ride height adjustment for stance and corner balancing
• Monotube shock construction — single-tube design for improved heat dissipation and more consistent damping performance versus twin-tube designs
• Application-specific engineering — designed specifically for the JZS160/UZS160 Lexus GS platform suspension geometry
• Complete kit — includes all four corner coilover assemblies for a full vehicle suspension upgrade
• Tein quality — engineered and manufactured in Japan by one of the most respected suspension brands in the enthusiast community
• TEIN Lifetime TechSupport — backed by Tein’s technical support program

Performance Benefits:

• Improved Handling Precision: Stiffer spring rates and monotube shock construction reduce body roll, improve cornering composure, and deliver a more direct, connected steering feel compared to the factory suspension
• 16-Way Damping Tuning: 16 clicks of rebound adjustment allow precise damping tuning for any driving condition — softer settings for daily comfort, firmer settings for canyon or track driving
• Ride Height Flexibility: Threaded lower mounts allow ride height adjustment independent of spring preload, enabling a lowered stance without sacrificing suspension travel or spring rate
• Reduced Body Roll: Higher spring rates and improved shock damping reduce the body roll that affects the GS platform’s handling balance under hard cornering
• Consistent Damping Performance: Monotube construction separates oil and gas chambers for more consistent damping performance and better heat management than twin-tube designs

Specifications:

• Brand: Tein
• Part Number: VST76-C1SA3-C
• Model: Flex Z
• Shock Type: Monotube
• Damping Adjustment: 16-way (rebound)
• Ride Height Adjustment: Yes (threaded lower mounts)
• Kit Coverage: Complete — all four corners

Fitment Information:

• 1998–2005 Lexus GS300 (JZS160L / JZS161) — 2JZ-GE engine
• 1998–2000 Lexus GS400 (UZS160) — 1UZ-FE V8 engine
• 2001–2005 Lexus GS430 (UZS161) — 3UZ-FE V8 engine
• Note: Verify your specific chassis code before ordering. The JZS160L designation is for left-hand drive GS300; JZS161 is the turbocharged variant — confirm your exact chassis code to ensure correct fitment.
• Installation: Professional installation strongly recommended
• Alignment: Full alignment required after installation

What’s Included:

• Tein Flex Z coilover assemblies — complete set (all four corners)
• Adjustment tools
• Installation instructions
• Tein Lifetime TechSupport registration

Installation Notes:

• Professional installation strongly recommended
• Full alignment required after installation — do not skip this step
• Set ride height with the vehicle at kerb weight before final alignment
• Torque all fasteners to Tein’s specified values
• Allow suspension to settle for 500–1,000 km before final alignment check
• Re-torque all fasteners after the settling period
• Damping adjustment is made via the adjustment knob on the shock body — start at a mid-range setting and adjust to preference

Tein Flex Z – The Platform:

The Tein Flex Z is Tein’s entry-level performance coilover lineup — a monotube, ride-height-adjustable, damping-adjustable coilover system that delivers genuine performance improvement over factory suspension at an accessible price point. The Flex Z is designed for enthusiasts who want the core benefits of a coilover system — ride height adjustment, improved handling, and damping tuning — without the cost of Tein’s higher-specification Street Advance Z or Super Racing lineups. For the GS platform, the Flex Z represents a significant step up from the factory suspension in both handling capability and stance flexibility.

The JZS160 / UZS160 Lexus GS Platform:

The 1998–2005 Lexus GS series (JZS160/UZS160 platform) is a rear-wheel-drive luxury sports sedan lineup that shares its underpinnings with the Toyota Aristo. The GS300 is powered by the Toyota 2JZ-GE inline-six — the naturally aspirated variant of the legendary 2JZ engine family. The GS400 and GS430 use Lexus’s 1UZ-FE and 3UZ-FE V8 engines respectively, delivering effortless torque in a refined package. All three variants share the same suspension architecture, making the Tein Flex Z a platform-wide coilover solution. A coilover upgrade is one of the most impactful handling modifications available for the GS platform, transforming the comfortable but body-roll-prone factory suspension into a more composed, driver-focused setup.

Why Tein?

Tein has been manufacturing performance suspension components in Japan since 1985. Their coilover lineup — from the entry-level Flex Z to the motorsport-grade Super Racing — is trusted by enthusiasts and professional racing teams worldwide. Tein’s application-specific engineering ensures correct spring rates, shock valving, and fitment for each platform rather than a generic universal approach, delivering a suspension system that works correctly from the first installation.

Perfect For:

• 1998–2005 Lexus GS300 (JZS160L/JZS161) owners seeking improved handling and ride height adjustment
• 1998–2000 Lexus GS400 (UZS160) builds wanting a lowered stance with genuine suspension performance improvement
• 2001–2005 Lexus GS430 (UZS161) owners upgrading from worn factory suspension to a complete coilover system
• Daily-driven GS builds seeking a balance of improved handling and adjustable ride comfort via 16-way damping
• 2JZ-GE and UZ-series V8 platform builds where the factory suspension is limiting handling capability

Pro Tip: Start with a mid-range damping setting (around 8 of 16) after installation and adjust from there based on your road conditions and driving style. Softer settings (1–6) suit rough roads and daily comfort; firmer settings (10–16) suit smooth roads and spirited driving.

Note: Full alignment is required after installation. Verify your exact chassis code (JZS160L, JZS161, UZS160, or UZS161) before ordering to confirm fitment.