Subaru STI Differential Lockdown System - Rear - PERRIN Performance ('15-'21) is a direct-fit upgrade that helps reduce rear differential movement and refines drivetrain behavior. It’s engineered to tighten the connection between the differential and chassis for a more predictable response under throttle and load.

This PERRIN Rear Differential Lockdown mounts to the factory locations and is designed to increase drivetrain rigidity, which can improve throttle response, traction feedback, and consistency during spirited driving or track use. The design focuses on controlling unwanted differential rotation and movement without altering OEM alignment or driveline geometry. Installation is straightforward for anyone familiar with basic drivetrain work, and the part is made for owners who want tangible mechanical improvement without extensive modification.

Features

• Vehicle fitment: Subaru STI '15-'21 rear differential
• Reduces rear differential movement for crisper throttle feel
• Direct-fit design that uses factory mounting locations
• Engineered by PERRIN Performance for compatibility and durability

If you have questions or want to confirm fitment for your build, call us directly and our technicians can help: 512-982-9393 (TX) or 562-981-6800 (CA). We have two service locations in Austin, Texas and the Los Angeles, California area where we offer professional installation and customization services.

If you are considering purchasing multiple items, please contact us for possible shipping discounts. We install on premises at both locations.

CA Residents: WARNING: Cancer and Reproductive Harm - www.P65Warnings.ca.gov