SMY Precision-Lock Rear Differential Bushing Inserts (08+ WRX, 08-21 STI)

Stop letting factory rubber rob your Subaru of the crisp, connected AWD power transfer it was built to deliver. Under hard acceleration, aggressive launches, and technical cornering, the factory rear differential twists and deflects within its soft, comfort-oriented rubber mounts. This movement creates drivetrain "slop," delays throttle response, and causes the notorious rear-end clunk during fast shifts. Our Precision-Lock Rear Differential Bushing Inserts are engineered to bridge the empty gaps in your OEM mounts, locking down the rear differential to eliminate unwanted movement without the massive headache of pressing out old factory rubber.

Features:

• Zero-Deflection Void-Fill Engineering: Designed using precision 3D-scanned tolerances to slide directly into the void spaces of your OEM rubber bushings. This reinforces the mount from the inside out, transforming a spongy factory assembly into a rigid, performance-ready setup.
• Performance-Tuned 85A Polyurethane: Molded from high-grade, oil- and heat-resistant 85A durometer polyurethane. This hits the ultimate sweet spot—stiff enough to eliminate drivetrain lash and power loss, but forgiving enough to keep street NVH (Noise, Vibration, and Harshness) well within a comfortable, daily-drivable range.
• Sharper Drivetrain Dynamics: By keeping the differential firmly aligned under load, you'll immediately notice crisper throttle response, more direct power delivery to the rear wheels, smoother gear transitions, and significantly enhanced stability when putting power down out of an apex.
• 100% Reversible Drop-In Install: Forget torches, reciprocating saws, and hydraulic presses. These inserts slip right over and around your existing OEM bushings in minutes using basic hand tools. Zero cutting, drilling, or permanent modifications required.

Includes:

• 2 x Front Rear Differential Inserts
• 2 x Rear Rear Differential Inserts
• 2 x Bushing Washers
• 1 x Super Lube Packet