KYB SR4521 Suspension Strut and Coil Spring Assembly - Front Left

KYB Strut-Plus Front Left Suspension Assembly

The KYB Strut-Plus SR4521 is a front left suspension strut and coil spring assembly built for direct replacement on select Toyota Prius V and Scion tC applications. It combines OE-style ride height restoration with application-specific damping to help bring back predictable handling, steering response, and stability.

Key Features

• OE-style replacement choice for Asian vehicles
• Includes a KYB Excel-G strut, a stronger steel outer shell, and precision-designed damping valves
• Pre-assembled for exact fitment and professional results
• Side-specific design for the left front position, as the vehicle manufacturer intended
• Engineered to help vehicles with electronic safety systems such as ESC and ABS
• High-carbon steel coil spring is developed around vehicle attributes and corner weights to help restore ride height within OE specifications
• Recipient of a 2018 industry award in the import aftermarket category

Product Details

KYB, an original equipment supplier, designs the Strut-Plus line to restore handling and control characteristics with a complete strut and spring assembly. The SR4521 is engineered for the front left corner and is built around the vehicle’s original suspension geometry, helping maintain proper ride height and steering feel. This part cross-references Monroe Shocks & Struts (e.g., 172683) for the same application. Fits 2012-2017 Toyota Prius V, front left. Fits 2011-2016 Scion tC, front left. KYB SR4521 is a direct-fit suspension solution for drivers looking to replace a worn front left strut assembly on a Toyota Prius V or Scion tC with an OE-style unit.

Common Issues This Part Can Address

• Excessive bouncing or poor damping from a worn front strut
• Uneven or sagging ride height at the front left corner
• Noisy or unstable suspension behavior over bumps
• Reduced steering precision or body control during cornering
• Suspension wear that affects ESC, ABS, or other electronic safety system performance

Installation Notes and Tips

Install the KYB SR4521 on the front left side only and follow the vehicle manufacturer’s instructions for strut and coil spring assembly replacement. Because this is a pre-assembled Strut-Plus unit, it is designed for exact fitment and professional installation on the specified Prius V and Scion tC applications. Verify position and application before installation.

Quality Assurance

KYB builds the Strut-Plus line using OE-supplier engineering standards and application-specific damping components to help restore factory-like ride and control characteristics. The SR4521 is designed around the original suspension layout and ride-height requirements for the listed vehicles.