Whiteline Rear Crossmember Mount Insert Kit – 2015-2021 Subaru WRX / STI

Whiteline Rear Crossmember Mount Insert Kit – 2015-2021 Subaru WRX / STI

Lock the Rear Subframe on the VA WRX and STI
The rear subframe crossmember on the 2015-2021 Subaru WRX and STI (VA chassis) uses rubber mounts with deliberate compliance for ride quality. Under performance driving loads, that compliance allows the subframe to shift — changing rear wheel geometry dynamically and reducing chassis consistency. Whiteline’s insert kit fills the void in the OEM mount housings with polyurethane, firming up the subframe connection without requiring full mount replacement.

DETAILS

• Polyurethane inserts for rear crossmember mount positions on VA WRX/STI
• Reduces rear subframe movement under performance driving loads
• Improves rear wheel geometry consistency and chassis response
• Insert design — simpler installation than full mount replacement
• Fitment: 2015-2021 Subaru WRX and STI (VA chassis)

VA Subframe Compliance and Its Effects
When the VA WRX or STI rear subframe moves under hard cornering, the entire rear suspension geometry shifts simultaneously — toe, camber, and thrust angle all change. On a car used for autocross or track days, this shows up as rear axle inconsistency that limits performance at the limit. Whiteline’s inserts address this directly.

Insert vs. Full Mount Replacement
Full subframe mount replacement requires pressing out the OEM rubber — significant effort and specialized tooling. Whiteline’s insert approach fills the void in the existing housing, achieving a significant compliance reduction with a far simpler installation. The result is most of the benefit with a fraction of the labor.

Part of the VA Rear Suspension Package
The rear crossmember insert kit works alongside rear differential mount bushings, trailing arm bushings, and rear sway bar upgrades to produce a fully sorted VA rear end. Doing the crossmember inserts alongside other rear mounts in one session is the most efficient approach.

Why Choose Whiteline

Whiteline has been engineering suspension components from their facility in Australia since 1979. Every product in their catalog is developed with a clear goal: measurable improvement in handling, stability, and tyre contact. Whiteline’s polyurethane bushings, sway bars, control arms, and alignment correction kits are engineered using finite element analysis and validated on track before they reach the market. Their components are direct-fit, bolt-on solutions designed for enthusiasts who want real performance gains without fabrication or custom work.

The RallySport Take

A high-value, easy-to-install improvement for the VA WRX and STI. Significant reduction in rear subframe movement with a straightforward installation. The install is straightforward but doing it correctly matters — clean the housing thoroughly before installation and apply grease to all polyurethane-to-metal contact surfaces. The improvement in drivetrain feel shows up immediately on the first hard acceleration run after installation.

What’s in the Box

• Polyurethane inserts for rear crossmember mount positions on VA WRX/STI
• Reduces rear subframe movement under performance driving loads
• Improves rear wheel geometry consistency and chassis response

Fitment