Cusco Rear Strut Tower Brace Type-OS 19+ Toyota Rav4 (XA5)

Upgrade the RAV4 XA5 Rear Sway Bar With Cusco's 24mm Solid Steel Replacement

The Cusco 1C4 311 B24 is a direct-replacement rear sway bar (stabilizer bar) for the 2019-2024 Toyota RAV4 XA5 in both 2WD and 4WD configurations, including gas and hybrid drivetrains. The CUS1C4 311 B24 replaces the factory hollow sway bar with a 24mm outer diameter solid steel unit, providing a 124% increase in effective stiffness over the OE 23.2mm hollow bar. Two Cusco bushings are included, and the installation reuses the original factory mounting brackets for a straightforward bolt-on fitment with no cutting or drilling required.

Key Features

• 1C4 311 B24 solid steel bar at 24mm OD replaces the OE 23.2mm hollow rear sway bar for a 124% stiffness increase
• Solid construction eliminates the flex inherent in hollow factory sway bars, improving lateral body roll resistance through corners
• Direct OE replacement fitment for 2019-2024 Toyota RAV4 XA5 in both 2WD and 4WD drivetrains, covering gasoline and hybrid models
• Two Cusco replacement bushings included for a complete installation without purchasing additional hardware
• Reuses the existing OE mounting brackets, keeping the installation reversible and eliminating the need for adapter hardware
• Estimated installation time of approximately 1 hour with standard hand tools
• Made in Japan by Cusco, a suspension manufacturer with over 40 years of motorsport development experience
• CUS1C4 311 B24 is compatible with all standard RAV4 XA5 trim levels across the production run, including hybrid (AXAH52/AXAH54) and gasoline (MXAA52/MXAA54) models

Vehicle Fitment

Specifications

What's Included

• 1x Cusco 1C4 311 B24 rear sway bar, 24mm solid steel
• 2x Cusco replacement bushings

About Cusco

Cusco has been developing suspension and chassis components in Japan since 1980, with decades of motorsport experience across rally, circuit racing, and time attack competition. Their sway bar lineup is built to OE-spec dimensional standards with upgraded diameter and solid construction to provide a measurable handling improvement without compromising ride quality on street-driven vehicles. The CUS1C4 311 B24 reflects the same engineering discipline Cusco applies across their full RAV4 XA5 suspension catalog.

FAQ

Is the Cusco 1C4 311 B24 a sway bar or a strut tower brace?

The CUS1C4 311 B24 is a rear sway bar (stabilizer bar) designed as a direct OE replacement for the 2019-2024 Toyota RAV4 XA5. It is not a strut tower brace. The Cusco strut tower brace for the RAV4 XA5 (front) carries part number 1C4-540-A. The 1C4 311 B24 mounts in the rear of the vehicle at the original sway bar brackets and reduces body roll through an increase in bar diameter and solid construction.

Does the Cusco 1C4 311 B24 fit the RAV4 Hybrid?

Yes. The Cusco 1C4 311 B24 is compatible with both the gasoline (MXAA52/MXAA54) and hybrid (AXAH52/AXAH54) variants of the 2019-2024 Toyota RAV4 XA5. The rear suspension mounting architecture is shared across gas and hybrid drivetrains in the XA5 generation, so the 1C4 311 B24 fits both configurations without modification.

Does the Cusco 1C4 311 B24 fit the RAV4 Prime?

The RAV4 Prime (AXAP54) uses a different chassis designation from the standard RAV4 and RAV4 Hybrid XA5. While the Prime shares the XA5 generation platform, its rear suspension and powertrain architecture may differ from the standard RAV4 XA5. Cusco has not confirmed compatibility with the RAV4 Prime for the 1C4 311 B24. Verify fitment with Cusco or the retailer before purchasing for a Prime application.

What is the stiffness difference between the Cusco 1C4 311 B24 and the stock RAV4 rear sway bar?

The stock 2019+ RAV4 XA5 rear sway bar uses a hollow 23.2mm outer diameter tube. The Cusco 1C4 311 B24 replaces it with a solid 24mm bar. Going from hollow to solid and increasing the diameter simultaneously provides approximately a 124% increase in torsional stiffness, which directly reduces body roll in cornering without requiring changes to ride height or spring rates.

Do I need new mounting brackets to install the Cusco 1C4 311 B24?

No. The Cusco 1C4 311 B24 is designed to reuse the original OE mounting brackets. Two replacement bushings are included in the kit. You do not need to purchase or fabricate adapter brackets. The installation is a straightforward swap of the OE sway bar and bushings using standard hand tools, with an estimated completion time of approximately 1 hour.

Will the Cusco 1C4 311 B24 affect my RAV4's ride quality on the street?

A stiffer rear sway bar reduces body roll in cornering but increases the coupling between the left and right rear wheels over bumps. For most drivers on street-driven RAV4s, the change is noticeable as improved cornering composure without a significant degradation in straight-line ride comfort. The 124% stiffness increase over OE is a meaningful upgrade but not an extreme one, and the solid bar is well-suited to street driving on the RAV4 platform.

Does the Cusco 1C4 311 B24 require an alignment after installation?

A sway bar replacement does not change toe, camber, or caster settings and does not require a four-wheel alignment. The sway bar affects roll stiffness only and does not alter the geometric relationship between the suspension and the chassis. No alignment is needed following installation of the CUS1C4 311 B24.

What tools are required to install the Cusco 1C4 311 B24 on the RAV4 XA5?

The installation reuses OE mounting brackets and only requires standard metric hand tools. A floor jack and jack stands to safely raise and support the rear of the vehicle, a set of metric sockets (17mm, 14mm commonly), and basic hand tools are sufficient for most installers. No specialty tools or press equipment are required for the 1C4 311 B24 installation. The estimated time is approximately 1 hour for a competent home mechanic with the vehicle safely supported.

What is the difference between the Cusco 1C4 311 B24 and adjustable sway bar options?

The CUS1C4 311 B24 is a fixed-rate OE-replacement sway bar. It does not have adjustable end links or multiple mounting hole positions to vary the effective spring rate. If your application requires tunable roll stiffness for track days or suspension setup adjustments, Cusco offers adjustable sway bars for some platforms. For street use and moderate performance driving, the fixed 24mm solid bar in the 1C4 311 B24 provides a well-defined, consistent improvement over the OE hollow bar without requiring periodic adjustment.

Installation Instructions

1. Safely raise and support the rear of the vehicle on jack stands. Do not work under a vehicle supported only by a floor jack.
2. Locate the OE rear sway bar, end links, and factory mounting brackets at the rear subframe.
3. Disconnect the OE sway bar end links from both sides of the sway bar.
4. Remove the two OE sway bar bracket bolts on each side. Retain the brackets for reinstallation with the Cusco bar.
5. Slide out the OE factory rear sway bar and set aside.
6. Remove the old OE bushings from the brackets. Install the two new Cusco bushings included with the 1C4 311 B24 into the original mounting brackets.
7. Position the Cusco 1C4 311 B24 solid 24mm bar into the bushing brackets at the original mounting locations.
8. Reinstall and torque the bracket bolts to the OE specification using a torque wrench.
9. Reconnect the end links to the Cusco sway bar on both sides and torque to OE specification.
10. Lower the vehicle, verify all fasteners are secure, and perform a short test drive to confirm the installation is complete and no noise or vibration is present.