Perrin 02-07 WRX/STi Rear Differential / Subframe Lockdown System

One of the most overlooked upgrades in a performance Subaru build is the elimination of drivetrain slop from the rear subframe and differential mounting points. The factory bushings in these areas are soft and prone to deflection under load, leading to drivetrain "wind-up," delayed throttle response, and vague rear-end behavior under hard acceleration, cornering, or on/off throttle transitions.

The Perrin Rear Differential / Subframe Lockdown System solves this by locking the differential and subframe more firmly to the chassis. Made from precision-machined aluminum and designed to fill the voids in the factory rubber bushings, this kit dramatically improves drivetrain feedback and rear-end stability. You’ll notice more direct throttle response, better traction on corner exit, and a more confidence-inspiring feel when powering through turns.

Installation is straightforward and fully reversible, making it one of the best bang-for-buck upgrades for spirited drivers and track enthusiasts. The parts are anodized for corrosion resistance and long-term durability, with an OEM-style fit that won’t rattle or require cutting or welding.

This upgrade is particularly effective on WRX, STI, and BRZ platforms where Subaru’s factory rear end geometry benefits from added rigidity during high G-loads. Whether you're launching hard, trail-braking, or simply tightening up rear-end feel during fast transitions, the Perrin Lockdown System transforms how planted your Subaru feels.

• Eliminates excessive drivetrain movement in the rear differential and subframe
• Improves throttle response, traction, and rear-end stability
• Machined aluminum lockdown inserts fill factory bushing voids precisely
• Ideal for spirited street driving, canyon carving, and track use
• Corrosion-resistant anodized finish with direct bolt-on installation