Kartboy Rear Diff/Carrier Wedge Lock System 2015-2021 WRX / 2015-2021 STI

Upgrade your 2015-2021 Subaru WRX STI’s rear differential stability with the Kartboy Rear Diff/Carrier Wedge Lock System. This premium drivetrain enhancement reduces unwanted movement in the rear differential, delivering a more connected and responsive driving experience. Perfect for spirited street driving or track use, it improves rear-end control and overall vehicle stability during aggressive cornering.

The kit includes four precision-machined aluminum inserts that lock the rear differential bushing inserts in place, plus four carrier inserts, all finished in durable black. These components work together to reinforce the rear diff carrier, minimizing slop and enhancing drivetrain response under harsh conditions. Designed specifically for Subaru WRX STI models from 2015 to 2021, this wedge lock system is a practical upgrade for enthusiasts seeking improved handling and reliability.

Ideal for Subaru performance enthusiasts, this Kartboy system offers a straightforward installation and long-lasting durability. Trust Subimods for quality Subaru drivetrain upgrades and elevate your WRX STI’s handling and confidence on the road or track. Shop drivetrain upgrades for your Subaru at Subimods today.